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Simple Summary: Pseudocirrhosis is a nodularity in the liver that it is typically associated with breast cancer liver metastases, and may occur as a response to chemotherapy and other systemic anticancer treatments. The types of patients who develop pseudocirrhosis, the treatments that they have received, and their outcomes are not well known. This study reviewed 170 patients with a diagnosis of pseudocirrhosis. A variety of different anticancer treatments were received, with taxanes (74.7%) and capecitabine (67.1%) being the most common. The median time between diagnosis of liver metastases and diagnosis of pseudocirrhosis was 17.1 months. The median overall survival once diagnosed with pseudocirrhosis was 7.6 months and patients with HER2+ disease had a statistically significant longer overall survival. To our knowledge, this is the largest dataset of pseudocirrhotic patients that has been published. It provides information to patients and clinicians on risk factors to develop pseudocirrhosis, and prognosis in different subtypes. Pseudocirrhosis is a diffuse nodularity of the liver that radiologically mimics cirrhosis but is a distinct pathological process. It is seen almost exclusively in patients with liver metastases and may represent a response to systemic treatment. Data on the risk factors for pseudocirrhosis and outcomes are limited. In total, 170 patients with a diagnosis of breast cancer and pseudocirrhosis in a 10-year period were identified and retrospectively analysed. Data were collected on baseline patient characteristics, treatments received, and outcomes. Median time between diagnosis of liver metastases and diagnosis of pseudocirrhosis was 17.1 months (range, 0–149 months). In total, 89.4% of patients received chemotherapy between their diagnosis of breast cancer liver metastases and their diagnosis of pseudocirrhosis, most commonly a taxane (74.7%) or capecitabine (67.1%), and the median treatment lines received was 3. Median OS from first diagnosis of pseudocirrhosis was 7.6 months (95% CI: 6.1–9.6 months) and was longer in patients with HER2+ disease at 16.7 months (95% CI: 6.4–32.9 months), which was statistically significant. In our study, pseudocirrhosis occurred in the presence of liver metastases and was associated with a poor prognosis. HER2+ patients with pseudocirrhosis had a better prognosis than other subtypes, but we did not identify other significant predictors of survival. Chemotherapy was not a prerequisite for pseudocirrhosis development, although the majority of patients had received at least one line of chemotherapy before pseudocirrhosis was diagnosed. [ABSTRACT FROM AUTHOR]

Simple Summary: The vaginal microbiome may play a role in racial disparities in ovarian cancer; there is evidence suggesting that it differs according to race and contributes to inflammation by producing or consuming compounds that can shape how ovarian cancer progresses. Our cross-sectional study aimed to investigate the extent to which chemical compounds, or metabolites, from vaginal fluid, also differ by race, and whether these metabolites are linked to systemic inflammation. Our study of 20 White and 16 Black patients identified 1 out of 99 metabolites, arachidonoylcarnitine (C20:4), as occurring at lower levels in Black and higher levels in White patients with ovarian cancer. More than one-third of vaginal fluid metabolites considered showed correlations with biomarkers of systemic inflammation. Our findings suggest that vaginal fluid metabolites likely differ by race, and may play an important role in inflammatory processes, which may be relevant to racial differences in ovarian cancer outcomes. These pilot findings have the potential to improve our understanding of biological mechanisms underlying racial disparities in ovarian cancer but need verification with larger sample sizes. The vaginal microbiome differs by race and contributes to inflammation by directly producing or consuming metabolites or by indirectly inducing host immune response, but its potential contributions to ovarian cancer (OC) disparities remain unclear. In this exploratory cross-sectional study, we examine whether vaginal fluid metabolites differ by race among patients with OC, if they are associated with systemic inflammation, and if such associations differ by race. Study participants were recruited from the Ovarian Cancer Epidemiology, Healthcare Access, and Disparities Study between March 2021 and September 2022. Our study included 36 study participants with ovarian cancer who provided biospecimens; 20 randomly selected White patients and all 16 eligible Black patients, aged 50–70 years. Acylcarnitines (n = 45 species), sphingomyelins (n = 34), and ceramides (n = 21) were assayed on cervicovaginal fluid, while four cytokines (IL-1β, IL-10, TNF-α, and IL-6) were assayed on saliva. Seven metabolites showed >2-fold differences, two showed significant differences using the Wilcoxon rank-sum test (p < 0.05; False Discovery Rate > 0.05), and 30 metabolites had coefficients > ±0.1 in a Penalized Discriminant Analysis that achieved two distinct clusters by race. Arachidonoylcarnitine, the carnitine adduct of arachidonic acid, appeared to be consistently different by race. Thirty-eight vaginal fluid metabolites were significantly correlated with systemic inflammation biomarkers, irrespective of race. These findings suggest that vaginal fluid metabolites may differ by race, are linked with systemic inflammation, and hint at a potential role for mitochondrial dysfunction and sphingolipid metabolism in OC disparities. Larger studies are needed to verify these findings and further establish specific biological mechanisms that may link the vaginal microbiome with OC racial disparities. [ABSTRACT FROM AUTHOR]

Simple Summary: Upfront surgery with adjuvant capecitabine is the only curative treatment for hilar cholangiocarcinoma. Unfortunately, most patients do not present with resectable disease and are treated with a combination of locoregional therapy and systemic therapy. This review will summarize existing literature and ongoing clinical trials focused on the multidisciplinary care of hilar cholangiocarcinoma. Cholangiocarcinoma (CCA) is a rare malignancy of the intrahepatic and extrahepatic biliary ducts. CCA is primarily defined by its anatomic location: intrahepatic cholangiocarcinoma versus extrahepatic cholangiocarcinoma. Hilar cholangiocarcinoma (HC) is a subtype of extrahepatic cholangiocarcinoma that arises from the common hepatic bile duct and can extend to the right and/or left hepatic bile ducts. Upfront surgery with adjuvant capecitabine is the standard of care for patients who present with early disease and the only curative therapy. Unfortunately, most patients present with locally advanced or metastatic disease and must rely on systemic therapy as their primary treatment. However, even with current systemic therapy, survival is still poor. As such, research is focused on developing targeted therapies and multimodal strategies to improve overall prognosis. This review discusses the work-up and management of HC focused on the most up-to-date literature and ongoing clinical trials. [ABSTRACT FROM AUTHOR]

Simple Summary: Drugs used to treat cancer are most often very toxic. Taking their high doses may adversely affect the patient's health, as a result of which the therapy, instead of helping, harms. An example of such a drug is 6-mercaptopurine, described in this paper. Due to these negative properties, it is necessary to create such systems that would release the drug in a controlled manner only in the vicinity of diseased tissues. In this work, a drug carrier was prepared that releases the drug only in the acidic environment of cancer, due to which healthy tissues will not be exposed to it. Systems that release the drug only in an acidic environment have not been described before and the application potential of such a carrier is very large. Hydroxy double salts are layered materials that are considered to be biocompatible. For this reason, research has been initiated on the possibility of their use in drug delivery. Despite their use for several types of drugs, their potential for controlled release of mercaptopurine (MERC) has not been studied. In this work, the synthesized hydroxy double salt (HDS) material was used as a carrier for this drug for the first time. The effectiveness of HDS synthesis has been proven by such techniques as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Based on the FT-IR and energy-dispersive X-ray spectroscopy (EDS) results, the effectiveness of drug sorption was proven. The exact amount of drug retained was determined by the UV-Vis technique. The obtained results indicate that the drug is evenly distributed on the surface of the carrier, which is important during the controlled delivery of drugs. In the most important stage of the research, the effectiveness of drug release in response to changes in the pH of the environment was proven. The drug is not released into an environment that mimics healthy human tissues. It is released only after contact with the acidic environment that usually surrounds cancer cells. The low cellular toxicity of HDS and significant cytotoxic effect of HDS-MERC were confirmed by in vitro studies on MCF-7 human breast and DU145 prostate cancer cell lines and non-cancerous keratinocytes HaCaT. Interestingly, coupling with the HDS carrier increased the cytotoxic effect of MERC towards DU145 cells. Such an "intelligent" drug carrier for mercaptopurine has not been previously described in the literature. The obtained results indicate its great potential. [ABSTRACT FROM AUTHOR]

Simple Summary: Colorectal cancer is one of the most prevalent neoplasms worldwide. Capecitabine is an oral fluoropyrimidine widely used to treat colorectal cancer in early and advanced stages. However, it shows high interindividual variability in its effectiveness and safety. This variability may be due to genetic variants in proteins involved in the pharmacokinetics and pharmacodynamics of the drug. Currently, only four variants of the DPYD gene are clinically relevant for the prediction of severe toxicity, and there are no validated predictive biomarkers of capecitabine effectiveness. Therefore, the search of potential predictive genetic biomarkers to personalize and optimize capecitabine therapy remains necessary. The aim of this study was to systematically review the literature published in the last 10 years on the influence of single-nucleotide polymorphisms in the main genes involved in capecitabine pharmacokinetics and pharmacodynamics on therapy outcomes in patients with colorectal cancer. The aim of this systematic review was to provide a comprehensive overview of the literature published in the last decade on the association of single-nucleotide polymorphisms in genes involved in the pharmacodynamic and pharmacokinetic pathways of capecitabine with treatment outcomes among colorectal cancer patients. A systematic search of the literature published in the last 10 years was carried out in two databases (Medline and Scopus) using keywords related to the objective. Quality assessment of the studies included was performed using an assessment tool derived from the Strengthening the Reporting of Genetic Association (STREGA) statement. Thirteen studies were included in this systematic review. Genes involved in bioactivation, metabolism, transport, mechanism of action of capecitabine, DNA repair, and folate cycle were associated with toxicity. Meanwhile, genes related to DNA repair were associated with therapy effectiveness. This systematic review reveals that several SNPs other than the four DPYD variants that are screened in clinical practice could have an impact on treatment outcomes. These findings suggest the identification of future predictive biomarkers of effectiveness and toxicity in colorectal cancer patients treated with capecitabine. However, the evidence is sparse and requires further validation. [ABSTRACT FROM AUTHOR]

Simple Summary: The introduction of venetoclax (VEN) to combination regimens has dramatically changed the paradigm of treatment for acute myeloid leukemia (AML) patients deemed unfit for intensive chemotherapy. Several researchers have reported that this regimen was successfully used as a bridge to potentially curative allogeneic hematopoietic stem cell transplantation (allo-HCT) in AML patients; however, data about clinical outcomes after allo-HCT are still lacking. In this study, we evaluated the post-transplant outcomes of 50 patients who received VEN-hypomethylating agents (HMA) treatment, either as initial therapy for newly diagnosed AML (n = 10) or as a salvage regimen for relapsed/refractory (R/R) AML (n = 40). The probabilities of overall survival, relapse-free survival, cumulative incidence of relapse, and nonrelapse mortality at 1 year were 63.7%, 59.3%, 28.5%, and 12.2%, respectively. Even though 30% of our data were from a second allo-HCT, our results suggest that allo-HCT following VEN-HMA therapy is a safe and effective treatment option. Recently, the combination of VEN-HMA has been shown to achieve durable responses in patients with both newly diagnosed (ND) and R/R-AML. We retrospectively evaluated the post-allo-HCT outcomes of 50 patients who received VEN-HMA therapy. In total, 10 were ND and 40 were R/R and, at the time of HCT, the median age was 53 years. In the ND- and R/R-AML groups, the percentage of patients who achieved CR/CRi or MLFS was 90% and 92.5%, respectively. In all, after a median follow-up of 13.7 months, the probabilities of overall survival (OS), relapse-free survival (RFS), cumulative incidence of relapse (CIR), and nonrelapse mortality (NRM) at 1 year were 63.7%, 59.3%, 28.5%, and 12.2%, respectively. In addition, the cumulative incidences of grade II–IV acute graft-versus-host disease (GVHD) and moderate–severe chronic GVHD at 1 year were 28.4% and 37.4%, respectively. In multivariate analysis, the factors associated with a statistically significant impact on OS were VEN-HMA cycle (p = 0.021), ELN risk group (p = 0.041), and the response to VEN-HMA therapy before allo-HCT (p = 0.003). Although 80% of our patients had R/R-AML and 30% underwent a second allo-HCT, our data still suggest that allo-HCT following VEN-HMA therapy is a safe and effective treatment option. [ABSTRACT FROM AUTHOR]

Simple Summary: Current treatments for patients with metastatic triple negative breast cancer (TNBC) are generally ineffective. This manuscript shows for the first time that the survival of mice with metastatic TNBC can be markedly increased through dietary manipulation. Our study revealed that the survival of some mice with metastatic TNBC was increased by replacing their normal diet with artificial diets in which the levels of amino acids (AAs) are manipulated, and the levels of lipids are markedly reduced. The anticancer activity of this non-pharmacological strategy was higher than that of drugs currently used in the treatment of patients with metastatic TNBC. This anticancer strategy also increased the survival of mice with other types of metastatic cancers. Manipulation of AA and lipid levels with artificial diets may be a useful strategy to treat patients with metastatic TNBC and other types of disseminated cancer. Patients with metastatic triple negative breast cancer (TNBC) need new therapies to improve the low survival rates achieved with standard treatments. In this work, we show for the first time that the survival of mice with metastatic TNBC can be markedly increased by replacing their normal diet with artificial diets in which the levels of amino acids (AAs) and lipids are strongly manipulated. After observing selective anticancer activity in vitro, we prepared five artificial diets and evaluated their anticancer activity in a challenging model of metastatic TNBC. The model was established by injecting 4T1 murine TNBC cells into the tail vein of immunocompetent BALB/cAnNRj mice. First-line drugs doxorubicin and capecitabine were also tested in this model. AA manipulation led to modest improvements in mice survival when the levels of lipids were normal. Reducing lipid levels to 1% markedly improved the activity of several diets with different AA content. Some mice fed the artificial diets as monotherapy lived much longer than mice treated with doxorubicin and capecitabine. An artificial diet without 10 non-essential AAs, with reduced levels of essential AAs, and with 1% lipids improved the survival not only of mice with TNBC but also of mice with other types of metastatic cancers. [ABSTRACT FROM AUTHOR]

Simple Summary: Colorectal cancer (CRC) is the second leading cause of cancer deaths, with approximately 15–25% of the primary diagnosis. MicroRNA-92a (miR-92a) is considered one of the most promising biomarkers for colorectal cancer diagnosis; however, at present the diagnostic accuracy of miR-92a for CRC remains inconclusive and the upstream regulatory mechanism is not well understood in CRC development. In this study, we firstly found that serum/plasma miR-92a had better diagnostic efficacy compared to stool samples in CRC through meta-analysis. Additionally, we confirmed that decreased miR-92a expression and secretion take place in CRC cells after knockdown of heterogeneous nuclear ribonucleoproteins A2/B1 (HNRNPA2B1) in vitro. The common peaks of N6-methyladenosine (m6A) and HNRNPA2B1 in proximate miR-92a suggested HNRNPA2B1 mediated miR-92a expression through m6A modification. Thus, we identified that miR-92a derived from blood could be a better noninvasive biomarker, and provide insight into the mechanism of miR-92a in the expression and secretion in CRC. MicroRNA-92a (miR-92a) may serve as a novel promising biomarker in multiple cancers, including colorectal cancer (CRC); however, the diagnostic accuracy and the underlying molecular mechanism of miR-92a in CRC is poorly understood. We first carried out meta-analysis and found that serum/plasma miR-92a yield better diagnostic efficacy when compared to stool samples and CRC tissues, and this finding was validated by our independent study through stool sample. Multiple bioinformatics assay indicated that miR-92a expression was positively correlated with heterogeneous nuclear ribonucleoproteins A2/B1 (HNRNPA2B1) expression and closely related with the clinical characteristics of CRC. Experimental evidence showed that knockdown of HNRNPA2B1 could significantly decrease miR-92a expression and secretion in RKO cells. HNRNPA2B1 mediated miR-92a via m6A RNA modification. These findings indicate that HNRNPA2B1-m6A RNA modification-derived MicroRNA-92a upregulation and section from the local CRC acts a candidate noninvasive serum biomarker in colorectal cancer. Our study provides a novel insight into miR-92a mechanisms in relation to both expression and secretion for CRC diagnosis. [ABSTRACT FROM AUTHOR]

Simple Summary: Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer-related death. In this study, we aimed to determine the biological function and regulatory mechanism of GMEB2 in CRC. We found that GMEB2 was highly expressed in CRC and significantly promoted the growth of CRC in vitro and in vivo. Mechanistically, GMEB2 acted as a transcription factor to activate ADRM1/NF-κB signalling and was upregulated by YTHDF1 through enhancing its mRNA stability. Our findings suggest that GMEB2 may serve as a new therapeutic target for CRC treatment in the future. Transcription factors are frequently aberrantly reactivated in various cancers, including colorectal cancer (CRC). However, as a transcription factor, the role of GMEB2 in cancer is still unclear, and further studies are needed. Here, we aimed to identify the function and mechanism of GMEB2 in regulating the malignant progression of CRC. GMEB2 was found to be highly expressed in online data analyses. We demonstrated that GMEB2 was markedly upregulated at both the mRNA and protein levels in CRC cells and tissues. GMEB2 knockdown inhibited CRC cell growth in vitro and in vivo. Mechanistically, as a transcription factor, GMEB2 transactivated the ADRM1 promoter to increase its transcription. Rescue experiments showed that ADRM1 downregulation partially reversed the promoting effects of GMEB2 on CRC growth in vitro. Moreover, the GMEB2/ADRM1 axis induced nuclear translocation of NF-κB, thus activating NF-κB signalling. Finally, we further revealed that YTHDF1 recognized and bound to the m6A site on GMEB2 mRNA, which enhanced its stability. Taken together, our findings reveal the crucial role and regulatory mechanism of GMEB2 in CRC for the first time and provide a novel potential therapeutic target for CRC therapy. [ABSTRACT FROM AUTHOR]

Simple Summary: There is no clear preference between S-1 and capecitabine in combination with platinum agent as first-line therapy for patients with HER2-negative unresectable advanced or recurrent gastric cancer (GC) with measurable disease. Although a distinguishing use of S-1 versus capecitabine based on histological classification has been studied, the present integrated analysis, using 162 individual participant data of GC patients with measurable disease, is the first to show that S-1 plus cisplatin (SP) achieves deeper tumor shrinkage than capecitabine plus cisplatin (XP), leading a longer overall survival although no differences in response rate or progression-free survival in differentiated GC. On the other hand, in undifferentiated GC, SP consistently showed better clinical results than XP. These findings thus have implications for the choice of oral fluoropyrimidine in the era of first line therapy in combination with oxaliplatin and immune checkpoint inhibitor. It has been suggested that the therapeutic efficacy of S-1 + cisplatin (SP) and capecitabine + cisplatin (XP) may differ depending on the histology of the tumor, but no clear evidence exists. Individual participant data were obtained from three randomized phase II trials in which such patients received either SP (S-1 [40–60 mg twice daily for 21 days] plus cisplatin [60 mg/m2 on day 8], every 5 weeks) or XP (capecitabine [1000 mg/m2 twice daily for 14 days] plus cisplatin [80 mg/m2 on day 1], every 3 weeks). A total of 162 patients were included, with 79 patients in the SP arm and 83 patients in the XP arm. Although there was also no difference between arms in ORR according to histological classification, differentiated tumors showed a significantly better OS (but not PFS) for SP versus XP that was associated with a deeper tumor shrinkage. Undifferentiated tumors showed a consistently better OS, and PFS for SP versus XP, likely because cases without tumor shrinkage tended to be fewer for SP. Our data thus showed that SP was superior to XP in this setting, but there were qualitative differences in therapeutic efficacy dependent on tumor histology. [ABSTRACT FROM AUTHOR]

Simple Summary: Pediatric patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) relapse or are refractory to chemotherapy despite the low frequency of TP53 mutations. The nucleolar stress response is one of the mechanisms that activate P53 by ribosomal protein L11 (RPL11). We hypothesized that the lack of nucleolar stress response is related to chemoresistance and relapse in some pediatric BCP-ALL cases. We revealed that clinical BCP-ALL therapeutics, such as 6-mercaptopurine, methotrexate, daunorubicin, and cytarabine, induced the nucleolar stress response, and its treatment susceptibility was dependent on the nucleolar stress response. Furthermore, we observed decreased RPL11 expression at relapse in seven children with BCP-ALL in comparison to that at onset. Our findings provide new insights into the anti-leukemia mechanism in BCP-ALL and multidrug resistance and relapse via the nucleolar stress response, suggesting that the nucleolar stress response may be a potential therapeutic strategy to predict chemosensitivity and improve chemoresistance in pediatric BCP-ALL. Approximately 20% of pediatric patients with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) relapse or are refractory to chemotherapy despite the low frequency of TP53 mutations. The nucleolar stress response is a P53-activating mechanism via MDM2 inhibition by ribosomal protein L11 (RPL11). We analyzed the role of the nucleolar stress response using BCP-ALL cell lines and patient samples by drug sensitivity tests, Western blotting, and reverse transcription polymerase chain reaction. We revealed that the nucleolar stress response works properly in TP53 wild-type human BCP-ALL cell lines. Next, we found that 6-mercaptopurine, methotrexate, daunorubicin, and cytarabine had anti-leukemic effects via the nucleolar stress response within BCP-ALL treatment. Comparing the samples at onset and relapse in children with BCP-ALL, RPL11 mRNA expression decreased at relapse in seven of nine cases. Furthermore, leukemia cells with relapse acquired resistance to these four drugs and suppressed P53 and RPL11 expression. Our findings suggest that the nucleolar stress response is a novel anti-leukemia mechanism in BCP-ALL. As these four drugs are key therapeutics for BCP-ALL treatment, dysfunction of the nucleolar stress response may be related to clinical relapse or refractoriness. Nucleolar stress response may be a target to predict and improve the chemotherapy effect for pediatric BCP-ALL. [ABSTRACT FROM AUTHOR]

Simple Summary: Several novel therapies are being developed to improve the management of patients with myelodysplastic syndromes. They include drugs aimed at improving hematopoiesis and differentiation of myeloid precursors, hypomethylating agents, several compounds that target intracellular molecular pathways, and immunotherapies. In this review article, we discuss how the novel drugs may address the several unmet needs of lower- and higher-risk patients. Myelodysplastic syndromes (MDS) are a very heterogeneous disease, with extremely variable clinical features and outcomes. Current management relies on risk stratification based on IPSS and IPSS-R, which categorizes patients into low (LR-) and high-risk (HR-) MDS. Therapeutic strategies in LR-MDS patients mainly consist of erythropoiesis stimulating agents (ESAs), transfusion support, and luspatercept or lenalidomide for selected patients. Current unmet needs include the limited options available after treatment failure, and the consequent transfusion burden with several hospital admissions and poor quality of life. Therapeutic approaches in HR-MDS patients are aimed at changing the natural course of the disease and hypometylating agents (HMA) are the first choice. The only potentially curative treatment is allogeneic stem cell transplant (allo-HCT), restricted to a minority of young and fit candidates. Patients unfit for or those that relapse after the abovementioned options harbor an adverse prognosis, with limited overall survival and frequent leukemic evolution. Recent advances in genetic mutations and intracellular pathways that are relevant for MDS pathogenesis are improving disease risk stratification and highlighting therapeutic targets addressed by novel agents. Several drugs are under evaluation for LR and HR patients, which differ by their mechanism of action, reported efficacy, and phase of development. This review analyzes the current unmet clinical needs for MDS patients and provides a critical overview of the novel agents under development in this setting. [ABSTRACT FROM AUTHOR]

Simple Summary: Adjuvant chemotherapy regimens tegafur/gimeracil/oteracil (S-1) and capecitabine plus oxaliplatin (CAPOX) have predominated, owing to evidence of their remarkable oncologic outcomes, however, there has been a lack of studies on the difference in efficacy between the two regimens. We conducted pairwise meta-analyses comparing the efficacy of S-1 and CAPOX regimens for overall survival (OS) and disease-free survival (DFS) in stage II or III gastric cancer patients. In all stages (stages II and III), the five-year OS was not different between the two regimens (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.78–1.17; p = 0.56). Additionally, the five-year DFS was not different at any stage (HR 1.00, 95% CI 0.85–1.18; p = 0.21). The present meta-analysis showed that five-year OS and DFS for stage II or III gastric cancer patients were comparable between the S-1 and CAPOX adjuvant chemotherapy regimens. Background: Adjuvant chemotherapy (AC) regimens tegafur/gimeracil/oteracil (S-1) and capecitabine plus oxaliplatin (CAPOX) have predominated, however, there has been a lack of studies on their differences in efficacy. Methods: We conducted pairwise meta-analyses comparing the efficacy of S-1 and CAPOX regimens for overall survival (OS) and disease-free survival (DFS) in stage II or III GC patients. Results: Three studies were enrolled and analyzed using a forest plot for meta-analysis. Two of them were propensity score matching studies, and the remaining one was a retrospective observational study. In all stages, the five-year OS was not different between the two regimens (HR 0.96, 95% CI 0.78–1.17; p = 0.56). Additionally, the 5-year DFS was not different at any stage (HR 1.00, 95% CI 0.85–1.18; p = 0.21). After omitting the retrospective observational study, the five-year OS (HR 1.40, 95% CI 0.53–3.73) and DFS (HR 1.41, 95% CI 0.57–3.44) of S-1 tended to be better in stage II, and the five-year OS (HR 0.81, 95% CI 0.56–1.16) and DFS (HR 0.85, 95% CI 0.63–1.13) of CAPOX tended to be better in stage III, without statistical significance. Conclusions: In the present meta-analysis, the five-year OS and DFS for stage II or III GC patients were comparable between S-1 and CAPOX regimens as AC. [ABSTRACT FROM AUTHOR]

Simple Summary: The development of several antiHuman Epidermal Growth Factor Receptor 2 (HER2) treatments over the last few years has improved the landscape of HER2-positive breast cancer. Despite this, relapse is still the main issue in HER2-positive breast cancer. The reasons for therapeutic failure lie in the heterogeneity of the disease itself, as well as in the drug resistance mechanisms. In this review, we intended to understand the milestones that have had an impact on this disease up to their implementation in clinical practice. In addition, understanding the underlying molecular biology of HER2-positive disease is essential for the optimization and personalization of the different treatment options. For this reason, we focused on two relevant aspects, which are triple-positive disease and the role that modulation of the immune response might play in treatment and prognosis. Despite the improvement achieved by the introduction of HER2-targeted therapy, up to 25% of early human epidermal growth factor receptor 2-positive (HER2+) breast cancer (BC) patients will relapse. Beyond trastuzumab, other agents approved for early HER2+ BC include the monoclonal antibody pertuzumab, the antibody-drug conjugate (ADC) trastuzumab-emtansine (T-DM1) and the reversible HER2 inhibitor lapatinib. New agents, such as trastuzumab-deruxtecan or tucatinib in combination with capecitabine and trastuzumab, have also shown a significant improvement in the metastatic setting. Other therapeutic strategies to overcome treatment resistance have been explored in HER2+ BC, mainly in HER2+ that also overexpress estrogen receptors (ER+). In ER+ HER2+ patients, target therapies such as phosphoinositide-3-kinase (PI3K) pathway inhibition or cyclin-dependent kinases 4/6 blocking may be effective in controlling downstream of HER2 and many of the cellular pathways associated with resistance to HER2-targeted therapies. Multiple trials have explored these strategies with some promising results, and probably, in the next years conclusive results will succeed. In addition, HER2+ BC is known to be more immunogenic than other BC subgroups, with high variability between tumors. Different immunotherapeutic agents such as HER-2 therapy plus checkpoint inhibitors, or new vaccines approaches have been investigated in this setting, with promising but controversial results obtained to date. [ABSTRACT FROM AUTHOR]

Simple Summary: In this paper we perform an introduction about pregnancy-associated cancer (PAC) and transplacental passage of antineoplastic agents. Furthermore, we describe therapeutic use and potential toxic effects of chemotherapeutic drug (alkylating agents, antimetabolites agents, anthracyclines, topoisomerase inhibitors, antimitotic agents, actinomycin-D, bleomycin) and targeted agents during pregnancy. This manuscript may be a useful and practical guide for the management of PAC, which is a challenge for clinicians that have to consider alike maternal benefits and fetal potential risks correlated to the antineoplastic treatment. The incidence of PAC is relatively infrequent among pregnant women. However, it has gradually increased in recent years, becoming a challenging area for clinicians that should take into account in the same way maternal benefits and fetal potential risks correlated to the antineoplastic treatment. None of the antineoplastic drugs is completely risk-free during the pregnancy, the timing of exposure and transplacental transfer properties influence the toxicity of the fetus. Despite the lack of guidelines about the management of PAC, several studies have described the use and the potential fetal and neonatal adverse events of antineoplastic drugs during pregnancy. We provide a review of the available literature about the transplacental passage and fetal effects of chemotherapy and targeted agents, to guide the clinicians in the most appropriate choices for the management of PAC. [ABSTRACT FROM AUTHOR]

Simple Summary: Surgical resection is the only potentially curative treatment for pancreatic cancer, and its indication relies on precise imaging criteria and on patients' operability. Chemotherapy is recommended, except for patients a with very short life expectancy. We sought to provide real-world information on the management and outcomes of pancreatic cancer. Among patients with a surgically resectable tumor, only half of those aged 75–84 and none after 85 actually underwent resection, even though the prognosis following pancreatectomy in elderly patients was similar to that in younger patients. Patients' refusal of chemotherapy increased from 7% before 75 years to 73% after 85 years. These results underline the need to develop guidelines for the management of elderly patients with pancreatic cancer and to generalize geriatric assessments. Background: Our objective was to describe real-world patterns of care and outcomes in pancreatic cancer. Methods: 912 patients diagnosed with pancreatic cancer from 2014 to 2017 were registered by the population-based cancer registry of Burgundy (France). Progression-free and net survival were estimated. Results: at diagnosis, 52% of tumors were associated with metastases. Among the 20% of patients fulfilling resectability criteria, half of those aged 75–84 years and none of those ≥85 years actually underwent resection. Age was not associated with 3-year observed survival in patients who underwent resection. Overall, 77% of patients aged <75 years, 55% of those aged 75–84 years and 8% of those ≥85 years received chemotherapy. Among patients who were offered chemotherapy, 73% of those aged ≥85 years refused. Chemotherapy toxicity was higher with Gemcitabine_Oxaliplatin/Gemcitabine_Abraxane and FOLFIRINOX than with Gemcitabine alone. Patients resected after induction FOLFIRINOX and those treated with adjuvant Gemcitabine presented the lowest risk of progression. Three-year net survival was 35% in patients with non-metastatic resectable tumors and under 10% for other patients. Conclusions: Only half of patients aged 75–84 years with a resectable tumor actually underwent resection. Two thirds of patients aged ≥85 years refused chemotherapy, thus underlining the need to expand geriatric assessments. [ABSTRACT FROM AUTHOR]

Pancreatic ductal adenocarcinoma (PDAC), commonly referred to as pancreatic cancer, ranks among the leading causes of cancer-related deaths in the Western world due to disease presentation at an advanced stage, early metastasis and generally a very limited response to chemotherapy or radiotherapy. Gemcitabine remains a cornerstone of PDAC treatment in all stages of the disease despite suboptimal clinical effects primarily caused by molecular mechanisms limiting its cellular uptake and activation and overall efficacy, as well as the development of chemoresistance within weeks of treatment initiation. To circumvent gemcitabine resistance in PDAC, several novel therapeutic approaches, including chemical modifications of the gemcitabine molecule generating numerous new prodrugs, as well as new entrapment designs of gemcitabine in colloidal systems such as nanoparticles and liposomes, are currently being investigated. Many of these approaches are reported to be more efficient than the parent gemcitabine molecule when tested in cellular systems and in vivo in murine tumor model systems; however, although promising, their translation to clinical use is still in a very early phase. This review discusses gemcitabine metabolism, activation and chemoresistance entities in the gemcitabine cytotoxicity pathway and provides an overview of approaches to override chemoresistance in pancreatic cancer. [ABSTRACT FROM AUTHOR]

Platelets have been demonstrated to be vital in cancer epithelial-mesenchymal transition (EMT), an important step in metastasis. Markers of EMT are associated with chemotherapy resistance. However, the association between the development of chemoresistance, EMT, and the contribution of platelets to the process, is still unclear. Here we report that platelets regulate the expression of (1) human equilibrative nucleoside transporter 1 (hENT1) and (2) cytidine deaminase (CDD), markers of gemcitabine resistance in pancreatic cancer. Human ENT1 (hENT1) is known to enable cellular uptake of gemcitabine while CDD deactivates gemcitabine. Knockdown experiments demonstrate that Slug, a mesenchymal transcriptional factor known to be upregulated during EMT, regulates the expression of hENT1 and CDD. Furthermore, we demonstrate that platelet-derived ADP and ATP regulate Slug and CDD expression in pancreatic cancer cells. Finally, we demonstrate that pancreatic cancer cells express the purinergic receptor P2Y12, an ADP receptor found mainly on platelets. Thus ticagrelor, a P2Y12 inhibitor, was used to examine the potential therapeutic effect of an ADP receptor antagonist on cancer cells. Our data indicate that ticagrelor negated the survival signals initiated in cancer cells by platelet-derived ADP and ATP. In conclusion, our results demonstrate a novel role of platelets in modulating chemoresistance in pancreatic cancer. Moreover, we propose ADP/ATP receptors as additional potential drug targets for treatment of pancreatic cancer. [ABSTRACT FROM AUTHOR]

Simple Summary: Organ preservation is becoming a topic of great interest for rectal cancer. Radiotherapy, often in association with chemotherapy, is playing a major role in achieving tumor sterilization and long-term local control. In order to achieve this goal, a high dose (>70 Gy) of radiotherapy is necessary. To avoid radiation toxicity of such a high dose, an endocavitary approach using contact X-ray 50 kV brachytherapy (CXB) is an attractive method. Historical series and two randomized trials in Europe give good evidence of the merit of CXB. The selection of early tumors is a key prognostic factor to achieve good results. A planned organ preservation treatment using CXB followed by chemoradiotherapy can be proposed to patients with T2–T3 a–b < 3 cm in diameter. At 3 years, the chance of local control should be close to 90% with good bowel function. Rectal adenocarcinoma is a quite radioresistant tumor. In order to achieve non-operative management (NOM) radiotherapy plays a major role. Targeted radiotherapy aiming at high precision 3D radiotherapy uses stereotactic image-guided external beam radiotherapy machines. To further safely increase the tumor dose, endocavitary brachytherapy (ECB) is an original approach. There are two different ways to perform such an ECB: contact X-ray brachytherapy (CXB) using a 50 kV X-ray generator with an X-ray tube positioned under eye guidance into the rectal cavity and high-dose-rate brachytherapy (HDRB) using iridium-192 sources positioned into the rectal cavity under image guidance. This study focused on CXB. CXB uses a small mobile generator that produces 50 kV X-rays with limited penetration. This technique is well adapted to accessible tumors of limited size and especially needs a high dose rate (≥15 Gy/minutes) for rectal tumors. It is performed on an ambulatory basis. A total dose between 80–110 Gy is delivered in 3–4 fractions over 3 to 6 weeks into a small volume (5 cm3). CXB was pioneered in the 1970s by Papillon using the Philips RT 50TM. Since 2009, the Papillon P50TM has been used in 11 institutions in Europe. The OPERA Phase III trial tested the hypothesis that a CXB boost (90 Gy/3 fr) compared to an EBRT boost (9 Gy/5 fr) for T2–T3 ab < 5 cm and N0–N1 < 8 mm will increase the 3-year organ preservation (OP) rate when combined with 45 Gy/5 weeks with concomitant capecitabine. Out of more than 300 patients with tumors < 3 cm (1962–1992), Papillon reported a long-term local control close to 85%. Similar results were published in Europe and USA at that time. The Lyon R96-2 Phase III trial (2004) demonstrated that, when combined with preoperative EBRT, a CXB boost (90 Gy/3 fr) significantly increased the rate of clinical complete response (cCR) and sphincter preservation, with some patients having OP at 10 years. With more than 2000 patients treated in Europe (2010–2020) using the Papillon 50TM, organ preservation appears possible in close to 80% of cases in selected early T2–T3. The OPERA trial closed after 141 inclusions (2015–2020) after an independent data monitoring committee recommendation because of promising results. At the 2-year follow-up (blinded data), the rate of cCR and OP were 77% and 72%, respectively, for the 141 tumors, and for T < 3 cm (61 pts), they were 86% and 85%, respectively, with good bowel function. The final results should be available in 2022. Organ preservation using NOM appears to be a promising approach for rectal cancer. A CXB boost with chemoradiotherapy in selected early T2–T3 could become an attractive option to achieve a planned OP. This approach should be proposed to well-informed patients after discussion in an MDT. [ABSTRACT FROM AUTHOR]

Simple Summary: Leptomeningeal metastases represent an unmet need due to the lack of effective therapy and poor survival. The tyrosine kinase inhibitor, neratinib, has demonstrated promising activity against brain metastases from HER2-positive breast cancer, as reported by the TBCRC and NALA trials, thus suggesting a potential activity also in leptomeningeal metastases when associated with capecitabine. The aim of the study was to investigate the efficacy and tolerability of neratinib in association with capecitabine in leptomeningeal metastases from heavily-pretreated breast cancer patients who failed multiple lines of treatment. Primary endpoints were 6-month overall survival and intracranial progression-free survival. Secondary endpoints were the responses assessed by whole CNS MRI performed every 8 weeks, neurological improvement, and safety. We obtained a median overall survival of 10 months, an intracranial progression-free survival of 4 months, neurological improvement and stable disease on an MRI lasting 6.5 months in six patients (60%). These preliminary findings suggest a potential activity of this treatment in LM from HER2-positive breast cancer that needs to be further investigated in larger datasets. Background: Leptomeningeal metastasis is a neurological complication from HER2-positive breast cancer with a poor prognosis and limited treatment options. This study has evaluated the activity of neratinib in association with capecitabine in 10 patients with LM from HER2-positive BC after the failure of multiple lines of treatment, including trastuzumab-based therapy, within a compassionate program, and a comparison was made with a historical control group of 10 patients. Methods: Patients aged ≥ 18 years with histological diagnosis of primary HER2-positive BC, either amplified or mutated, and newly-diagnosed LM were enrolled. Coexistence of BM that has or has not received radiotherapy, as well as prior chemotherapy, hormone therapy, or monoclonal HER2-targeting antibodies or antibody–drug conjugates, were allowed, with the exclusion of lapatinib. Results: Six-months OS was 60% with a median OS of 10 months (95% CI: 2.00–17.0). Three-month intracranial PFS was 60% with a median intracranial PFS of 4.0 months (95% CI: 2.00–6.0). The neurological benefit was observed in 70% of patients with a median duration of neurological response of 6.5 months. The best radiological response was stable disease in 60% of patients. Conclusions: This small series shows that the combination of neratinib and capecitabine is a safe treatment in LM from heavily pretreated HER2-positive BC with clinical efficacy in some patients and is worth investigating in a larger study. [ABSTRACT FROM AUTHOR]

Simple Summary: Proton pump inhibitors are frequently used in cancer patients to alleviate some symptoms, epigastric pain or heartburn. However, acid suppression decreases the absorption of some oral-targeted anticancer treatments (tyrosine kinase inhibitors, CDK4/6 inhibitors) and induces changes in the gut microbiome. Recent data are showing that these interactions have important clinical impacts and medical oncologists and patients must be aware of these possible interactions. Multikinase inhibitors (MKIs), and particularly tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (CPIs), are currently some of the major breakthroughs in cancer treatment. Proton pump inhibitors (PPIs) revolutionised the treatment of acid-related diseases, but are frequently overused for epigastric pain or heartburn. However, long-term acid suppression from using PPIs may lead to safety concerns, and could have a greater impact in cancer patients undergoing therapy, like bone fractures, renal toxicities, enteric infections, and micronutrient deficiencies (iron and magnesium). Moreover, acid suppression may also affect the pharmacokinetics of drugs (at least during acid suppression) and decrease the absorption of many molecularly-targeted anticancer therapies, which are mostly weak bases with pH-dependent absorption. This type of drug-drug interaction may have detrimental effects on efficacy, with major clinical impacts described for some orally administrated targeted therapies (erlotinib, gefitinib, pazopanib, palbociclib), and conflicting results with many others, including capecitabine. Furthermore, the long-term use of PPIs results in severe alterations to the gut microbiome and recent retrospective analyses have shown that the benefit of using CPIs was suppressed in patients treated with PPIs. These very expensive drugs are of great importance because of their efficacy. As the use of PPIs is not essential, we must apply the precautionary principle. All these data should encourage medical oncologists to refrain from prescribing PPIs, explaining to patients the risks of interaction in order to prevent inappropriate prescription by another physician. [ABSTRACT FROM AUTHOR]

Combination therapy is a common practice in many medical disciplines. It is defined as the use of more than one drug to treat the same disease. Sometimes this expression describes the simultaneous use of therapeutic approaches that target different cellular/molecular pathways, increasing the chances of killing the diseased cell. This short review is concerned with therapeutic combinations in which PDT (Photodynamyc Therapy) is the core therapeutic partner. Besides the description of the principal methods used to assess the efficacy attained by combinations in respect to monotherapy, this review describes experimental results in which PDT was combined with conventional drugs in different experimental conditions. This inventory is far from exhaustive, as the number of photosensitizers used in combination with different drugs is very large. Reports cited in this work have been selected because considered representative. The combinations we have reviewed include the association of PDT with anti-oxidants, chemotherapeutics, drugs targeting topoisomerases I and II, antimetabolites and others. Some paragraphs are dedicated to PDT and immuno-modulation, others to associations of PDT with angiogenesis inhibitors, receptor inhibitors, radiotherapy and more. Finally, a look is dedicated to combinations involving the use of natural compounds and, as new entries, drugs that act as proteasome inhibitors. [ABSTRACT FROM AUTHOR]

Simple Summary: For many years, patients with breast cancer and brain metastases were excluded from participation in clinical trials. It was believed that anticancer drugs could not cross the blood–brain barrier. However, recent evidence strongly suggests that some drugs can act against brain metastases, with the greatest intracranial response rate reported in the case of capecitabine, neratinib plus capecitabine, trastuzumab deruxtecan and tucatinib plus trastuzumab and capecitabine. In this article, we discuss the achievements in systemic therapy of breast cancer patients with brain metastases. We stress on the newest clinical trial results which indicate tremendous progress in HER2-positive breast cancer. On the other hand, in patients with triple-negative breast cancer or hormone-receptor-positive brain metastases, much fewer compounds were discovered. Based on the presented results, patients with active brain metastases should be routinely included in clinical trials with novel agents. Brain metastases are detected in 5% of patients with breast cancer at diagnosis. The rate of brain metastases is higher in HER2-positive and triple-negative breast cancer patients (TNBC). In patients with metastatic breast cancer, the risk of brain metastases is much higher, with up to 50% of the patients having two aggressive biological breast cancer subtypes. The prognosis for such patients is poor. Until recently, little was known about the response to systemic therapy in brain metastases. The number of trials dedicated to breast cancer with brain metastases was scarce. Our review summarizes the current knowledge on this topic including very significant results of clinical trials which have been presented very recently. We focus on the intracranial response rate of modern drugs, including new antibody–drug conjugates, HER2- targeted tyrosine kinase inhibitors and other targeted therapies. We highlight the most effective and promising drugs. On the other hand, we also suggest that further efforts are needed to improve the prognosis, especially patients with TNBC and brain metastases. The information contained in this article can help oncologists make treatment-related decisions. [ABSTRACT FROM AUTHOR]

Simple Summary: Pancreatic cancer is considered incurable, and most cases are detected in the advanced stages. Establishing a new, effective interventional treatment for advanced pancreatic cancer is a pressing issue. Pretreatment with gemcitabine had a restraining effect on the homologous DNA recombination repair (HRR) of DNA crosslinking, inhibiting the function of Rad51, of which expression is found to be increased in pancreatic cancer. The aim of our prospective study was to assess the potential value of the arterial administration of DNA crosslinking agents after intravenous administration of low-dose gemcitabine for patients with advanced pancreatic cancer. We confirmed, among forty-five patients with unresectable advanced pancreatic cancer, that a patient subgroup of locally advanced pancreatic cancer (LAPC, 10 patients) who underwent these treatment courses successively more than twice in the first 6 months had 33 months of overall survival, 31 months of local progression free survival, and a complete response of 40%. This treatment can be a new treatment option for LAPC. (1) Background: Pretreatment by Rad51-inhibitory substances such as gemcitabine followed by arterial chemotherapy using antineoplastic agents causing DNA crosslink might be more beneficial for patients with locally advanced pancreatic cancers than conventional treatments. The efficacy of arterial administration of DNA crosslinking agents with pretreatment of intravenous low-dose gemcitabine for patients with unresectable locally advanced or metastatic pancreatic cancer (LAPC or MPC) is evaluated. (2) Methods: A single-arm, single-center, institutional review board-approved prospective study was conducted between 2005 and 2015. Forty-five patients (23 LAPC, 22 MPC) were included. Patients received a weekly low dose of gemcitabine intravenously for three weeks followed by arterial administration of mitomycin C and epirubicin hydrochloride at tumor-supplying arteries on the fifth or sixth week. This treatment course was repeated at 1.5-to-2-month intervals. Overall survival (OS), local progression-free survival (LPFS), and therapeutic response were evaluated. LAPC or MPC were divided according to treatment compliance, excellent or poor (1 or 2), to subgroups L1, L2, M1, and M2. (3) Results: OS of LAPC and MPC were 23 months and 13 months, respectively. The OS of LAPC with excellent treatment compliance (subgroup L1, 10 patients) was 33 months with 31 months of LPFS, and four patients (40%) had a complete response (CR). The OS of the L1 subgroup was significantly longer than those of other subgroups L2, M1, and M2, which were 17 months, 17 months, and 8 months, respectively. As Grade 3 adverse effects, severe bone marrow suppression, interstitial pneumonitis, and hemolytic uremic syndrome were observed in six (13.0%), three (6.5%), and three (6.5%) patients, respectively. (4) Conclusions: Arterial DNA crosslinking with the systemic restraint of homologous recombination repair can be a new treatment option for LAPC. [ABSTRACT FROM AUTHOR]

Simple Summary: This research suggests a new potential therapeutic approach to pancreatic ductal adenocarcinoma to improve drug effectiveness and overcome drug resistance. A double actively targeted gemcitabine delivery system, consisting of polymeric micelles, was developed by microfluidic technique to ensure a narrow size distribution, a good colloidal stability, and drug-encapsulation efficiency for the selective and controlled release of the loaded drug, in response to the pH variations and uPAR expression in tumors. In vitro studies assessed that the release of the drug in the acidic environment was higher than in the neutral one, and that the pH-responsive and uPAR-targeted polymeric micelles enhanced the antitumor properties of gemcitabine in models resembling the pancreatic tumor microenvironment. Pancreatic ductal adenocarcinoma (PDAC) represents a great challenge to the successful delivery of the anticancer drugs. The intrinsic characteristics of the PDAC microenvironment and drugs resistance make it suitable for therapeutic approaches with stimulus-responsive drug delivery systems (DDSs), such as pH, within the tumor microenvironment (TME). Moreover, the high expression of uPAR in PDAC can be exploited for a drug receptor-mediated active targeting strategy. Here, a pH-responsive and uPAR-targeted Gemcitabine (Gem) DDS, consisting of polymeric micelles (Gem@TpHResMic), was formulated by microfluidic technique to obtain a preparation characterized by a narrow size distribution, good colloidal stability, and high drug-encapsulation efficiency (EE%). The Gem@TpHResMic was able to perform a controlled Gem release in an acidic environment and to selectively target uPAR-expressing tumor cells. The Gem@TpHResMic displayed relevant cellular internalization and greater antitumor properties than free Gem in 2D and 3D models of pancreatic cancer, by generating massive damage to DNA, in terms of H2AX phosphorylation and apoptosis induction. Further investigation into the physiological model of PDAC, obtained by a co-culture of tumor spheroids and cancer-associated fibroblast (CAF), highlighted that the micellar system enhanced the antitumor potential of Gem, and was demonstrated to overcome the TME-dependent drug resistance. In vivo investigation is warranted to consider this new DDS as a new approach to overcome drug resistance in PDAC. [ABSTRACT FROM AUTHOR]

Simple Summary: Pancreatic cancer (PDAC) is a deadly disease, exacerbated by obesity, which lacks effective therapeutic interventions. Most PDAC has a limited response to immune- and chemotherapy. Treating PDAC is made additionally challenging by the rapid emergence of muscle wasting and cachexia, which predict poor response to several therapies. We have found that dietary supplementation with β-hydroxy-β-methylbutyrate promotes immunosurveillance in PDAC tumors and protects muscle. This dietary supplement has the potential to be an important adjuvant in PDAC therapy, opening the doors to immunotherapy response. Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related deaths in the United States, and effective therapies for PDAC are currently lacking. Moreover, PDAC is promoted and exacerbated by obesity, while cachexia and sarcopenia are exceptionally common comorbidities that predict both poor survival and treatment response. Managing PDAC with immunotherapies has thus far proven ineffective, partly due to the metabolically hostile tumor microenvironment. β-hydroxy-β-methylbutyrate (HMB), a metabolite of leucine commonly used as a dietary supplement to boost muscle growth and immune function, may be an attractive candidate to augment PDAC therapy. We therefore sought to test the hypothesis that HMB would enhance antitumor immunity while protecting mouse muscle mass. Control and diet-induced obese C57BL/6 male mice bearing subcutaneously injected Panc02 tumors were supplemented with 1% HMB and treated with or without 50 mg/kg gemcitabine (n = 15/group). HMB was associated with reduced muscle inflammation and increased muscle fiber size. HMB also reduced tumor growth and promoted antitumor immunity in obese, but not lean, mice, independent of the gemcitabine treatment. Separately, in lean tumor-bearing mice, HMB supplementation promoted an anti-PD1 immunotherapy response (n = 15/group). Digital cytometry implicated the decreased abundance of M2-like macrophages in PDAC tumors, an effect that was enhanced by anti-PD1 immunotherapy. We confirmed that HMB augments M1-like macrophage (antitumor) polarization. These preclinical findings suggest that HMB has muscle-sparing and antitumor activities against PDAC in the context of obesity, and that it may sensitize otherwise nonresponsive PDAC to immunotherapy. [ABSTRACT FROM AUTHOR]

Simple Summary: Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers, with a five-year survival rate of less than 8%. There is a need to develop drugs with anti-invasive activity and in vitro tumor models for effective drug screening to improve patient outcomes. Since PDAC invasiveness is mainly induced by tumor-associated stromal cells, we aimed to develop a three-dimensional (3D) PDAC tumor model that mimics in vivo conditions. Additionally, we examined the usefulness of this model for evaluating chemotherapeutic drugs. We succeeded in establishing a 3D co-culture model of multicellular PDAC tumor spheroids, cancer-associated fibroblasts, and tumor-associated macrophages using a microfluidic channel chip platform. We also demonstrated the suitability of this model for evaluating cell-type dependent cytotoxicity, anti-invasive activity, and the association between the two. These results may help develop a novel system for screening the efficacy of chemotherapeutic drugs against PDAC and other solid tumors in the future. Activated pancreatic stellate cells (aPSCs) and M2 macrophages modulate tumor progression and therapeutic efficacy in pancreatic ductal adenocarcinoma (PDAC) via epithelial-mesenchymal transition (EMT). Here, our aim was to analyze the anti-invasion effects of anti-cancer agents where EMT-inducing cancer-stroma interaction occurs under three-dimensional (3D) culture conditions. We used microfluidic channel chips to co-culture pancreatic tumor spheroids (TSs) with aPSCs and THP-1-derived M2 macrophages (M2 THP-1 cells) embedded in type I collagen. Under stromal cell co-culture conditions, PANC-1 TSs displayed elevated expression of EMT-related proteins and increased invasion and migration. When PANC-1 TSs were exposed to gemcitabine, 5-fluorouracil, oxaliplatin, or paclitaxel, 30–50% cells were found unaffected, with no significant changes in the dose-response profiles under stromal cell co-culture conditions. This indicated intrinsic resistance to these drugs and no further induction of drug resistance by stromal cells. Paclitaxel had a significant anti-invasion effect; in contrast, oxaliplatin did not show such effect despite its specific cytotoxicity in M2 THP-1 cells. Overall, our findings demonstrate that the TS-stroma co-culture model of PDAC is useful for activity profiling of anti-cancer agents against cancer and stromal cells, and analyzing the relationship between anti-stromal activity and anti-invasion effects. [ABSTRACT FROM AUTHOR]

Simple Summary: Pancreatic adenocarcinoma (PDAC) is a disease with an incredibly grim prognosis. Most patients die within one year of receiving the diagnosis. There are currently very few tools to help the clinician decide between treatment options and evaluate prognosis at an individual level. The aim of the current study was to assess the effect of promoter hypermethylation of secreted frizzled-related protein 1 (phSFRP1) as an independent prognostic blood-based biomarker in gemcitabine-treated patients with advanced PDAC. The study was conducted as a combined discovery and validation study. Analysis in both cohorts confirmed that patients with phSFRP1 had overall poorer survival compared to those without hypermethylation. Thus, phSFRP1 shows promise as an independent prognostic biomarker in this patient group and can hopefully aid the clinician and patient find the correct balance between quantity and quality of life. No reliable predictive blood-based biomarkers are available for determining survival from pancreatic adenocarcinoma (PDAC). This combined discovery and validation study examines promoter hypermethylation (ph) of secreted frizzled-related protein 1 (SFRP1) in plasma-derived cell-free DNA as an independent prognostic marker for survival and Gemcitabine effectiveness in patients with stage IV PDAC. We conducted methylation-specific polymerase chain reaction analysis of the promoter region of the SFRP1 gene, based on bisulfite treatment. Survival was analyzed with Kaplan–Meier curves, log-rank test, and Cox regression. The discovery cohort included 40 patients, 25 receiving Gem. Gem-treated patients with phSFRP1 had a shorter median overall survival (mOS) (4.4 months) than unmethylated patients (11.6 months). Adjusted Cox-regression yielded a hazard rate (HR) of 3.48 (1.39–8.70). The validation cohort included 58 Gem-treated patients. Patients with phSFRP1 had a shorter mOS (3.2 months) than unmethylated patients (6.3 months). Adjusted Cox regression yielded an HR of 3.53 (1.85–6.74). In both cohorts, phSFRP1 was associated with poorer survival in Gem-treated patients. This may indicate that tumors with phSFRP1 are more aggressive and less sensitive to Gem treatment. This knowledge may facilitate tailored treatment of patients with stage IV PDAC. Further studies are planned to examine phSFRP1 in more intensive chemotherapy regimens. [ABSTRACT FROM AUTHOR]

Simple Summary: Death receptors may induce cellular death upon ligand binding but also activate other pro-inflammatory mechanisms in cancer cells, which may increase malignancy. The transcription factor NFkB works as a central hub in this system and connects the signaling of three major death ligands: TNF, CD95L and TRAIL. In this study, we analyzed the impact of a recombinant inhibitor of CD95L on the respective tri-lateral cross-talk using highly malignant pancreatic cancer cells as a model and in context of the standard chemotherapeutic agent, gemcitabine. We show that the specific "uni-lateral" inhibitor also clearly impacts the two other cytokines and importantly reduces the pro-inflammatory status of pancreatic cancer cells as well as their stem cell phenotype. Consequently, the local recurrent tumor growth after surgery of the primary tumor was reduced. Further, the unwanted, pro-inflammatory side-effects of gemcitabine are inhibited. Despite the potential apoptotic functions, the CD95/CD95L system can stimulate survival as well as pro-inflammatory signaling, particularly through the activation of NFκB. This holds true for the TNF/TNFR and the TRAIL/TRAILR systems. Thus, signaling pathways of these three death ligands converge, yet the specific impact of the CD95/CD95L system in this crosstalk has not been well studied. In this study, we show that gemcitabine stimulates the expression of pro-inflammatory cytokines, such as IL6 and IL8, under the influence of the CD95/CD95L system and the pharmacological inhibitor, sCD95Fc, substantially reduced the expression in two PDAC cell lines, PancTuI-luc and A818-4. The stem cell phenotype was reduced when induced upon gemcitabine as well by sCD95Fc. Moreover, TNF-α as well as TRAIL up-regulate the expression of CD95 and CD95L in both cell lines. Conversely, we detected a significant inhibitory effect of sCD95Fc on the expression of both IL8 and IL6 induced upon TNF-α and TRAIL stimulation. In vivo, CD95L inhibition reduced xeno-transplanted recurrent PDAC growth. Thus, our findings indicate that inhibition of CD95 signaling altered the chemotherapeutic effects of gemcitabine, not only by suppressing the pro-inflammatory responses that arose from the CD95L-positive tumor cells but also from the TNF-α and TRAIL signaling in a bi-lateral crosstalk manner. [ABSTRACT FROM AUTHOR]

Simple Summary: Thymic carcinoma is identified as thoracic neoplasm having low sensitivity to systemic chemotherapy. As first-line setting, platinum-based chemotherapy is administered, but, it is difficult to achieve long-term survival. Therefore, salvage chemotherapy is clinically considered as second or third line treatment. This study reviewed the therapeutic significance of several kinds of cytotoxic agents and molecular targeting drugs in patients with previously treated thymic carcinoma. The clinical trials of salvage chemotherapy in patients with thymic carcinoma are limited, and we cannot draw an optimal conclusion due to the small sample size. However, S-1, amrubicin, docetaxel, pemetrexed, and paclitaxel, sunitinib and lenvatinib yielded some efficacy to such patients. As S-1 and amrubicin are limited to Japan and East Asian, it remains unclear which regimens are better as second-line setting. Further investigation is warranted to establish the clinical evidence of salvage chemotherapy in advanced or metastatic thymic carcinoma by large-scale study. Thymic carcinoma is a rare neoplasm, and it is difficult to achieve complete remission with systemic chemotherapy. In advanced or recurrent thymic carcinoma, platinum-based chemotherapy is chosen as the first-line setting; however, it remains unclear which regimen is better to improve its outcome. It remains unknown whether salvage chemotherapy should be administered to patients with platinum-based chemotherapy-refractory thymic carcinoma. Currently, several clinical studies have investigated the efficacy of second-line settings for advanced thymic carcinoma. As cytotoxic agents, S-1, amrubicin, pemetrexed, docetaxel, paclitaxel, and gemcitabine have been reported as prospective phase II studies or retrospective studies. The overall response rates (ORRs) of S-1, amrubicin, and pemetrexed were 25–50%, 11–44.4%, and 9–10%, respectively. Molecular targeting drugs, such as sunitinib, everolimus, and lenvatinib, also provide clinical effectiveness with tolerability after the failure of platinum-based regimens. Based on the results of the prospective phase II study, the ORR, median progression-free survival, and median overall survival were 16.6% and 5.6 months, respectively, in everolimus, 26% and 7.2 months, respectively, in sunitinib, and 38% and 9.3 months, respectively, in lenvatinib. Although it is difficult to compare each study, lenvatinib appears to be better in increasing efficacy as a second-line setting. However, each study had a small sample size, which may have biased the results of their studies. Further investigation is warranted to elucidate the therapeutic significance of salvage chemotherapy in advanced thymic carcinoma in a large-scale study. [ABSTRACT FROM AUTHOR]

Simple Summary: To investigate a possible treatment strategy for hormone receptor (HR)-positive, HER2-negative advanced and/or metastatic breast cancer (AMBC), we investigated the clinical usefulness of adding capecitabine to maintenance endocrine therapy after induction chemotherapy and the efficacy of reinduction chemotherapy. Patients who had received bevacizumab–paclitaxel induction therapy and did not have progressive disease were randomized to receive maintenance therapy with endocrine therapy alone (group E; n = 46) or endocrine therapy plus capecitabine (group EC; n = 44). The median progression-free survival (PFS) under maintenance therapy (primary endpoint) was significantly longer in group EC than in group E (11.1 vs. 4.3 months; hazard ratio, 0.53; p < 0.01). At 24 months from the induction therapy start, the overall survival (OS) rate was significantly higher in group EC than in group E (83.5% vs. 62.3%; p = 0.02). Therefore, the addition of capecitabine to maintenance endocrine therapy may be a beneficial option after induction chemotherapy for HR-positive, HER2-negative AMBC patients. Optimal treatment strategies for hormone receptor (HR)-positive, HER2-negative advanced and/or metastatic breast cancer (AMBC) remain uncertain. We investigated the clinical usefulness of adding capecitabine to maintenance endocrine therapy after induction chemotherapy and the efficacy of reinduction chemotherapy. Patients who had received bevacizumab–paclitaxel induction therapy and did not have progressive disease (PD) were randomized to maintenance therapy with endocrine therapy alone (group E) or endocrine plus capecitabine (1657 mg/m2/day on days 1–21, q4w) (group EC). In case of PD after maintenance therapy, patients received bevacizumab–paclitaxel reinduction therapy. Ninety patients were randomized. The median progression-free survival (PFS) under maintenance therapy (primary endpoint) was significantly longer in group EC (11.1 {95% CI, 8.0–11.8} months) than in group E (4.3 {3.6–6.0} months) (hazard ratio, 0.53; p < 0.01). At 24 months from the induction therapy start, the overall survival (OS) was significantly longer in group EC than in group E (hazard ratio, 0.41; p = 0.046). No difference was found in the time to failure of strategy (13.9 and 16.6 months in groups E and EC, respectively). Increased capecitabine-associated toxicities in group EC were tolerable. Addition of capecitabine to maintenance endocrine therapy may be a beneficial option after induction chemotherapy for HR-positive, HER2-negative AMBC patients. [ABSTRACT FROM AUTHOR]

Simple Summary: Due to the availability of effective combination chemotherapies such as gemcitabine/nab-paclitaxel (GNP) or FOLFIRINOX, neoadjuvant treatment of borderline resectable (BRPC) and locally advanced pancreatic cancer (LAPC) has been increasingly investigated in recent years. However, due to toxicity, FOLFIRINOX is only available for selected patients and data on GNP are scarce. The aim of this systematic review and meta-analysis, which is to our knowledge the first addressing this question, is to evaluate the value of GNP in patients with BRPC and LAPC. We provide a comprehensive overview on data of 21 studies, comprising 950 patients treated with neoadjuvant GNP. The pooled overall and R0 resection rates were 36% and 26%, respectively. Resection rates were higher in BRPC (49%) compared to LAPC (16%). With acceptable toxicity and a median overall survival rate ranging from 12 to 30 months, neoadjuvant GNP has considerable value in this setting, with more prospective trials being warranted. Therapy with gemcitabine and nab-paclitaxel (GNP) is the most commonly used palliative chemotherapy, but its advantage in the neoadjuvant setting remains unclear. Accordingly, our aim is to evaluate the impact of first-line neoadjuvant therapy with GNP in patients with borderline resectable (BRPC) and locally advanced pancreatic cancer (LAPC). A systematic search for published studies until August 2020 was performed. The primary endpoint included resection and R0 resection rates in the intention-to-treat population. Secondary endpoints were response rate, survival and toxicity. Among 21 studies, 950 patients who received neoadjuvant GNP were evaluated. Treatment with GNP resulted in surgical resection and R0 resection rates as follows: 49% (95% CI 30–68%) and 36% (95% CI 17–58%) for BRPC and 16% (95% CI 7–26%) and 11% (95% CI 5–19%) for LAPC, respectively. The objective response rates and the median overall survival (mOS) ranged from 0 to 67% and 12 to 30 months, respectively. Neutropenia (range 5–77%) and neuropathy (range 0–22%) were the most commonly reported grade 3 to 4 adverse events. Neoadjuvant chemotherapy with GNP can be performed safely and with valuable effects in patients with BRPC and LAPC. The utility of GNP in comparison to FOLFIRINOX in the neoadjuvant setting requires further investigation in prospective randomized trials. [ABSTRACT FROM AUTHOR]

Simple Summary: In the past decade, the interaction between intestinal microbiota and colorectal cancer has been an active research area. Microbial metabolites, which could act locally and systematically, have a significant impact on the development of colorectal cancer, especially by inciting immune responses. In this paper, we systematically reviewed the recent insights on microbial metabolites and their immunoregulation on colorectal cancer and discussed the controversial role of some metabolites, hoping to provide a different understanding of the role of bacterial metabolites in colon carcinogenesis. A growing body of research has found close links between the human gut microbiota and colorectal cancer (CRC), associated with the direct actions of specific bacteria and the activities of microbiota-derived metabolites, which are implicated in complex immune responses, thus influencing carcinogenesis. Diet has a significant impact on the structure of the microbiota and also undergoes microbial metabolism. Some metabolites, such as short-chain fatty acids (SCFAs) and indole derivatives, act as protectors against cancer by regulating immune responses, while others may promote cancer. However, the specific influence of these metabolites on the host is conditional. We reviewed the recent insights on the relationships among diet, microbiota-derived metabolites, and CRC, focusing on their intricate immunomodulatory responses, which might influence the progression of colorectal cancer. [ABSTRACT FROM AUTHOR]

Simple Summary: Triple-negative breast cancers (TNBCs) are mainly treated with standard chemotherapies. Combined therapies have been demonstrated as a promising treatment strategy in clinics. The aim of this study was to develop a new formulation of combined chemotherapies facilitated with a targeted delivery vehicle. We found that the mertansine and gemcitabine with different anti-cancer mechanisms resulted in high cytotoxicity in TNBC cells. The in vivo evaluations using two TNBC xenograft models confirmed the anti-tumor efficacy, i.e., significantly reduced tumor growth rate. Furthermore, the antibody-tagged liposomes effectively delivered the therapeutic drugs to TNBC tumor, which could reduce the side effects. This study is highly translational and the targeted liposomal drug formulation can be further investigated in future clinical trials for TNBC treatment. Triple-negative breast cancers (TNBCs) are highly aggressive and recurrent. Standard cytotoxic chemotherapies are currently the main treatment options, but their clinical efficacies are limited and patients usually suffer from severe side effects. The goal of this study was to develop and evaluate targeted liposomes-delivered combined chemotherapies to treat TNBCs. Specifically, the IC50 values of the microtubule polymerization inhibitor mertansine (DM1), mitotic spindle assembly defecting taxane (paclitaxel, PTX), DNA synthesis inhibitor gemcitabine (GC), and DNA damage inducer doxorubicin (AC) were tested in both TNBC MDA-MB-231 and MDA-MB-468 cells. Then we constructed the anti-epidermal growth factor receptor (EGFR) monoclonal antibody (mAb) tagged liposomes and confirmed its TNBC cell surface binding using flow cytometry, internalization with confocal laser scanning microscopy, and TNBC xenograft targeting in NSG female mice using In Vivo Imaging System. The safe dosage of anti-EGFR liposomal chemotherapies, i.e., <20% body weight change, was identified. Finally, the in vivo anti-tumor efficacy studies in TNBC cell line-derived xenograft and patient-derived xenograft models revealed that the targeted delivery of chemotherapies (mertansine and gemcitabine) can effectively inhibit tumor growth. This study demonstrated that the targeted liposomes enable the new formulations of combined therapies that improve anti-TNBC efficacy. [ABSTRACT FROM AUTHOR]

Simple Summary: There is an urgent need to improve the therapeutic options in pancreatic cancer. In this study, we assessed the ability of two standard-of-care chemotherapeutic regimens to modulate the levels of PD-L1 mRNA isolated from plasma-derived microvesicles (MVs) of patients with pancreatic cancer. Our findings demonstrate for the first time a statistically significant difference in MV-derived PD-L1 mRNA levels at 3 months vs. baseline in patients treated with GEMnPAC, compared to those receiving FOLFIRINOX. Although these findings need to be confirmed in larger prospective cohorts, they can represent a rational basis for testing the hypothesis that the GEMnPAC schedule may be used as an immunotherapy-modulating regimen in PDAC patients due to its capability of increasing PD-L1 mRNA expression. Pancreatic ductal adenocarcinoma (PDAC) is a non-immunogenic tumor poorly responsive to immune checkpoint inhibitors. This study investigates the effect of 5-fluorouracil (5-FU), irinotecan, and oxaliplatin (FOLFIRINOX), and gemcitabine plus nab-paclitaxel (GEMnPAC) regimens on PD-L1 mRNA expression in plasma-derived microvesicles (MVs) in 50 PDAC patients. Plasma was collected before starting chemotherapy and after 3 months of treatment. mRNA was extracted from MVs, and PD-L1 expression was measured by digital droplet PCR. Twenty-eight patients were PD-L1 positive in MVs at baseline, of which 18 were in the GEMnPAC cohort and 10 in the FOLFIRINOX one. The amount of PD-L1 expression in MVs increased from baseline to 3 months of treatment in patients receiving GEMnPAC (median value 0.002 vs. 0.005; p = 0.01) compared to those treated with FOLFIRINOX (median 0.003 vs. 0.004; p = 0.97). The increase in PD-L1 mRNA expression in MVs was not related to tumor response (PR + SD: p = 0.08; PD: p = 0.28). Our findings demonstrate that GEMnPAC can increase PD-L1 mRNA expression in patient-derived circulating MVs, providing a rationale for testing the efficacy of this regimen in sequential or simultaneous combinations with immunotherapy in PDAC patients. [ABSTRACT FROM AUTHOR]

Simple Summary: The BET bromodomain inhibitor JQ1 slows tumor growth in preclinical models of pancreatic cancer. However, as a single agent, it does not induce tumor regressions. We hypothesized that JQ1 would sensitize pancreatic tumors to gemcitabine, a drug used for patients with this tumor type. We evaluated the efficacy of JQ1 + gemcitabine in pancreatic cancer cell lines and in two patient-derived xenograft models. The data show that JQ1 + gemcitabine is synergistic in vitro and that this combination has greater efficacy than either drug alone in vivo. RNA-seq analyses to identify mechanisms that may contribute to the observed synergy demonstrated that JQ1 + gemcitabine selectively inhibits expression of proteins necessary for cholesterol biosynthesis and lipid metabolism that support tumor cell proliferation. The data indicate that a BET inhibitor + gemcitabine warrants further investigation for the treatment of pancreatic cancer. Gemcitabine is used to treat pancreatic cancer (PC), but is not curative. We sought to determine whether gemcitabine + a BET bromodomain inhibitor was superior to gemcitabine, and identify proteins that may contribute to the efficacy of this combination. This study was based on observations that cell cycle dysregulation and DNA damage augment the efficacy of gemcitabine. BET inhibitors arrest cells in G1 and allow increases in DNA damage, likely due to inhibition of expression of DNA repair proteins Ku80 and RAD51. BET inhibitors (JQ1 or I-BET762) + gemcitabine were synergistic in vitro, in Panc1, MiaPaCa2 and Su86 PC cell lines. JQ1 + gemcitabine was more effective in vivo than either drug alone in patient-derived xenograft models (P < 0.01). Increases in the apoptosis marker cleaved caspase 3 and DNA damage marker γH2AX paralleled antitumor efficacy. Notably, RNA-seq data showed that JQ1 + gemcitabine selectively inhibited HMGCS2 and APOC1 ~6-fold, compared to controls. These proteins contribute to cholesterol biosynthesis and lipid metabolism, and their overexpression supports tumor cell proliferation. IPA data indicated that JQ1 + gemcitabine selectively inhibited the LXR/RXR activation pathway, suggesting the hypothesis that this inhibition may contribute to the observed in vivo efficacy of JQ1 + gemcitabine. [ABSTRACT FROM AUTHOR]

Simple Summary: The treatment of advanced pancreatic cancer represents a major challenge because of its chemoresistance and low survival rate. The aim of this research is to test a new antitumor agent (sodium selenite) in pancreatic cancer, both in vitro and in vivo, focusing on the molecular mechanisms involved and its combination with traditional chemotherapy (gemcitabine). Our results show that selenite has a strong antitumor effect against pancreatic cancer, via parthanatos cell death, and enhances the effect of gemcitabine via the p38 pathway in both in vitro and in vivo assays. These results could improve the outcome of pancreatic cancer patients and could be the start of future clinical trials. Sodium selenite acts by depleting enzymes that protect against cellular oxidative stress. To determine its effect alone or in combination with gemcitabine (GMZ) in pancreatic cancer, we used PANC-1 and Pan02 cell lines and C57BL mice bearing a Pan02-generated tumor. Our results demonstrated a significant inhibition of pancreatic cancer cell viability with the use of sodium selenite alone and a synergistic effect when associated with GMZ. The molecular mechanisms of the antitumor effect of sodium selenite alone involved apoptosis-inducing factor (AIF) and the expression of phospho-p38 in the combined therapy. In addition, sodium selenite alone and in association with GMZ significantly decreased the migration capacity and colony-forming ability, reduced tumor activity in multicellular tumor spheroids (MTS) and decreased sphere formation of cancer stem cells. In vivo studies demonstrated that combined therapy not only inhibited tumor growth (65%) compared to the untreated group but also relative to sodium selenite or GMZ used as monotherapy (up to 40%), increasing mice survival. These results were supported by the analysis of C57BL/6 albino mice bearing a Pan02-generated tumor, using the IVIS system. In conclusion, our results showed that sodium selenite is a potential agent for the improvement in the treatment of pancreatic cancer and should be considered for future human clinical trials. [ABSTRACT FROM AUTHOR]

Simple Summary: Currently, platinum-based neoadjuvant chemotherapy (NAC) is becoming a standard treatment for use in patients with muscle-invasive bladder cancer. However, comparisons of oncologic outcomes for the two most commonly used NAC regimens, ddMVAC (dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin) and GC (gemcitabine and cisplatin), are controversial. We sought to compare the oncologic outcomes of these two regimens via a systematic review and meta-analysis of all the available studies published to date. Through this, we aimed to provide evidence on the optimal NAC regimen for use in muscle-invasive bladder cancer. Platinum-based neoadjuvant chemotherapy (NAC) is widely used for treating muscle-invasive bladder cancer (MIBC). A systematic review was performed following PRISMA guidelines. PubMed, Embase, and the Cochrane Library were searched up to December 2020. We conducted a meta-analysis to compare the oncologic outcomes of ddMVAC (dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin) and GC (gemcitabine and cisplatin), which are the most widely used NAC regimens. Endpoints included pathologic complete response (pCR), pathologic downstaging (pDS), overall survival (OS), and cancer-specific survival (CSS). Five studies, with a total of 1206 patients, were included for meta-analysis. pCR was observed in 35.2% of the ddMVAC arm and in 25.1% of the GC arm, and pCR was significantly higher in ddMVAC than in GC (odds ratio (OR), 1.45; 95% confidence interval (CI), 1.11–1.89; p = 0.006). There was no significant difference in pDS (OR, 1.37; CI, 0.84–2.21; p = 0.20). OS was significantly higher in ddMVAC than in GC (hazard ratio, 2.16; CI, 1.42–3.29; p = 0.0004). Only one study reported CSS outcomes. The results of this analysis indicate that ddMVAC is superior to GC in terms of pCR and OS, suggesting that ddMVAC is more effective than GC in NAC for MIBC. However, this should be interpreted with caution because of the inherent limitations of retrospective studies. [ABSTRACT FROM AUTHOR]

Simple Summary: Pancreatic cancer (PC) has a poor prognosis. Even though surgical resection and adjuvant chemotherapy is the most effective therapy, recurrence remains common. In this paper, we investigate the effectiveness of dual inhibition of hepatocyte growth factor (HGF) and c-MET when used as treatment after surgical resection of PC in mice. The HGF/c-Met pathway is a major mediator of pancreatic stellate cell (stromal cell)—PC cell interactions. Using single-cell RNA sequencing, we also investigated the existence of co-metastasising cells, circulating pancreatic stellate cells (cPSCs), as facilitators of PC metastasis. We found that HGF/c-Met inhibition reduced both the risk and rate of disease progression after resection and that this effect was associated with reduced cPSC counts. In conclusion, this study is the first to demonstrate the efficacy of adjuvant HGF/c-Met inhibition and is also the first to confirm the existence of cPSCs in PC. Background: Inhibition of hepatocyte growth factor (HGF)/c-MET pathway, a major mediator of pancreatic stellate cell (PSC)−PC cell interactions, retards local and distant cancer progression. This study examines the use of this treatment in preventing PC progression after resection. We further investigate the postulated existence of circulating PSCs (cPSCs) as a mediator of metastatic PC. Methods: Two orthotopic PC mouse models, produced by implantation of a mixture of luciferase-tagged human pancreatic cancer cells (AsPC-1), and human PSCs were used. Model 1 mice underwent distal pancreatectomy 3-weeks post-implantation (n = 62). One-week post-resection, mice were randomised to four treatments of 8 weeks: (i) IgG, (ii) gemcitabine (G), (iii) HGF/c-MET inhibition (HiCi) and (iv) HiCi + G. Tumour burden was assessed longitudinally by bioluminescence. Circulating tumour cells and cPSCs were enriched by filtration. Tumours of Model 2 mice progressed for 8 weeks prior to the collection of primary tumour, metastases and blood for single-cell RNA-sequencing (scRNA-seq). Results: HiCi treatments: (1) reduced both the risk and rate of disease progression after resection; (2) demonstrated an anti-angiogenic effect on immunohistochemistry; (3) reduced cPSC counts. cPSCs were identified using immunocytochemistry (α-smooth muscle actin+, pan-cytokeratin−, CD45−), and by specific PSC markers. scRNA-seq confirmed the existence of cPSCs and identified potential genes associated with development into cPSCs. Conclusions: This study is the first to demonstrate the efficacy of adjuvant HGF/c-Met inhibition for PC and provides the first confirmation of the existence of circulating PSCs. [ABSTRACT FROM AUTHOR]

Simple Summary: Pancreatic ductal adenocarcinoma (PDAC) patient care lacks well-established molecular characterization of the tumors, which would allow for better-personalized treatment selection if improved. To overcome this problem, preclinical models are frequent-ly adopted tools used to elucidate the molecular characterization of PDAC tumors. Unfortunately, the vast majority of studies using these preclinical models fail when transferred to patients despite initially promising results. This study presents for the first time a comparison between three preclinical matched models directly derived from patient tumors. We show that their applicability to preclinical studies should be considered with a complementary focus, avoiding tumor-based direct extrapolations, which might generate misleading conclusions and consequently the overlook of clinically relevant features. We finally highlight the importance of validating and refining predictive transcriptomic signatures using a combination of these models. Purpose: Compare pancreatic ductal adenocarcinoma (PDAC), preclinical models, by their transcriptome and drug response landscapes to evaluate their complementarity. Experimental Design: Three paired PDAC preclinical models—patient-derived xenografts (PDX), xenograft-derived pancreatic organoids (XDPO) and xenograft-derived primary cell cultures (XDPCC)—were derived from 20 patients and analyzed at the transcriptomic and chemosensitivity level. Transcriptomic characterization was performed using the basal-like/classical subtyping and the PDAC molecular gradient (PAMG). Chemosensitivity for gemcitabine, irinotecan, 5-fluorouracil and oxaliplatin was established and the associated biological pathways were determined using independent component analysis (ICA) on the transcriptome of each model. The selection criteria used to identify the different components was the chemosensitivity score (CSS) found for each drug in each model. Results: PDX was the most dispersed model whereas XDPO and XDPCC were mainly classical and basal-like, respectively. Chemosensitivity scoring determines that PDX and XDPO display a positive correlation for three out of four drugs tested, whereas PDX and XDPCC did not correlate. No match was observed for each tumor chemosensitivity in the different models. Finally, pathway analysis shows a significant association between PDX and XDPO for the chemosensitivity-associated pathways and PDX and XDPCC for the chemoresistance-associated pathways. Conclusions: Each PDAC preclinical model possesses a unique basal-like/classical transcriptomic phenotype that strongly influences their global chemosensitivity. Each preclinical model is imperfect but complementary, suggesting that a more representative approach of the clinical reality could be obtained by combining them. Translational Relevance: The identification of molecular signatures that underpin drug sensitivity to chemotherapy in PDAC remains clinically challenging. Importantly, the vast majority of studies using preclinical in vivo and in vitro models fail when transferred to patients in a clinical setting despite initially promising results. This study presents for the first time a comparison between three preclinical models directly derived from the same patients. We show that their applicability to preclinical studies should be considered with a complementary focus, avoiding tumor-based direct extrapolations, which might generate misleading conclusions and consequently the overlook of clinically relevant features. [ABSTRACT FROM AUTHOR]

Simple Summary: Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies. Chemotherapy has had limited success in extending the life span of patients with advanced PDAC. Thus, new treatment approaches are needed. Heme oxygenase-1 (HO-1) is a key enzyme for the protection of cells against oxidative stress. Interestingly, HO-1 is overexpressed in several cancers, including PDAC. In the present study, our findings demonstrate the novel role of HO-1 in vivo in PDAC progression and in sensitizing tumor cells to cytotoxic chemotherapy by modulating the tumor microenvironment (TME). Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a poor prognosis. Tumor hypoxia plays an active role in promoting tumor progression, malignancy, and resistance to therapy in PDAC. We present evidence that nab-paclitaxel–gemcitabine (NPG) and/or a hypoxic tumor microenvironment (TME) up-regulate heme oxygenase-1 (HO-1), providing a survival advantage for tumors. Using PDAC cells in vitro and a PDAC mouse model, we found that NPG chemotherapy up-regulated expression of HO-1 in PDAC cells and increased its nuclear translocation. Inhibition of HO-1 with ZnPP and SnPP sensitized PDAC cells to NPG-induced cytotoxicity (p < 0.05) and increased apoptosis (p < 0.05). Additionally, HO-1 expression was increased in gemcitabine-resistant PDAC cells (p < 0.05), and HO-1 inhibition increased GEM-resistant PDAC sensitivity to NPG (p < 0.05). NPG combined with HO-1 inhibitor inhibited tumor size in an orthotopic model. In parallel, HO-1 inhibition abrogated the influx of macrophages and FoxP3+ cells, while increasing the proportion of CD8+ infiltration in the pancreatic tumors. These effects were mediated primarily by reducing expression of the immunosuppressive cytokine IL-10. [ABSTRACT FROM AUTHOR]

Simple Summary: The present article reviews the state of the art of metronomic chemotherapy use to treat the principal types of cancers, namely breast, non-small cell lung cancer and colorectal ones, and of the most recent progresses in understanding the underlying mechanisms of action. Areas of novelty, in terms of new regimens, new types of cancer suitable for Metronomic chemotherapy (mCHT) and the overview of current ongoing trials, along with a critical review of them, are also provided. Metronomic chemotherapy treatment (mCHT) refers to the chronic administration of low doses chemotherapy that can sustain prolonged, and active plasma levels of drugs, producing favorable tolerability and it is a new promising therapeutic approach in solid and in hematologic tumors. mCHT has not only a direct effect on tumor cells, but also an action on cell microenvironment, by inhibiting tumor angiogenesis, or promoting immune response and for these reasons can be considered a multi-target therapy itself. Here we review the state of the art of mCHT use in some classical tumour types, such as breast and no small cell lung cancer (NSCLC), see what is new regarding most recent data in different cancer types, such as glioblastoma (GBL) and acute myeloid leukemia (AML), and new drugs with potential metronomic administration. Finally, a look at the strategic use of mCHT in the context of health emergencies, or in low –and middle-income countries (LMICs), where access to adequate healthcare is often not easy, is mandatory, as we always need to bear in in mind that equity in care must be a compulsory part of our medical work and research. [ABSTRACT FROM AUTHOR]

Simple Summary: Neuroendocrine tumors grade 3 (NET G3) are a newly defined subgroup of neuroendocrine neoplasms. They do not respond well to platinum + etoposide-based chemotherapy. The alternative suggested options have not been analyzed in untreated NET G3 patients so far, therefore the optimal treatment strategy for these tumors is unclear. In our analysis we showed that FOLFOX is the most active regimen holding the highest chance of tumor shrinkage, whereas temozolomide/capecitabine is the most effective, leading to the most durable tumor control. Well-differentiated grade 3 neuroendocrine tumors (NET G3) have been distinguished from poorly differentiated neuroendocrine carcinomas (NEC) in the most current WHO classifications. Commonly applied first-line chemotherapy protocols with cisplatin or carboplatin in combination with etoposide (PE) are less effective in NET G3 than NEC. Suggested alternative treatment protocols have not been studied in first-line therapy of NET G3 so far. We performed a retrospective analysis of patients with NET G3 in the databases of 3 German cancer centers. Out of 142 patients, 136 patients received palliative first-line therapy: overall response rate (ORR) was 35.1% for PE (n = 37), 56.4% for FOLFOX (n = 39), 27.3% for temozolomide/capecitabine (TEM/CAP) (n = 22), 45.0% for streptozotocin/5-fluorouracil (STZ/5-FU) (n = 20), and 16.7% for other (n = 18). Median progression-free survival (PFS) for PE was 6.9 months. Compared to PE, PFS in the other treatment groups was 6.9 months for FOLFOX (p = 0.333), 12.0 months for TEM/CAP (p = 0.093), 4.8 months for STZ/5-FU (p = 0.919), and 14.1 months for other (p = 0.014). In a univariate setting, all non-PE patients combined showed a significantly prolonged PFS vs. PE (9.0 months; p = 0.049) which could not be confirmed in a multivariate analysis. In conclusion, NET G3 with FOLFOX showed the highest ORR, and with TEM/CAP showed the longest PFS. Further prospective evaluation of the optimal therapeutic strategy for this tumor entity is needed. [ABSTRACT FROM AUTHOR]

Simple Summary: Non-small cell lung cancer (NSCLC) claims almost 80% of the total lung cancer cases, with the late-stage disease having an estimated median survival time of up to five years. Patients with NSCLC benefit from traditional maximum tolerated dose (MTD) chemotherapy alone or combined with immunotherapy. However, efficacious such treatment options lead to side effects and poor patient quality of life. We show that metronomic (MTR) chemotherapy—based on the daily administration of chemotherapeutics in low, nontoxic doses—could potentially supplement MTD treatment options and indirectly prevent tumor growth leading to efficacy and less toxicity. Importantly when MTR chemotherapy is combined with an immunotherapy anti-PD1 agent, the anticipated efficacy is achieved with less toxicity, thus providing new options for the treatment of NSCLC. Pioneering studies on tumor and immune cell interactions have highlighted immune checkpoint inhibitors (ICIs) as revolutionizing interventions for the management of NSCLC, typically combined with traditional MTD chemotherapies, which usually lead to toxicities and resistance to treatment. Alternatively, MTR chemotherapy is based on the daily low dose administration of chemotherapeutics, preventing tumor growth indirectly by targeting the tumor microenvironment. The effects of MTR administration of an oral prodrug of gemcitabine (OralGem), alone or with anti-PD1, were evaluated. Relevant in vitro and in vivo models were developed to investigate the efficacy of MTR alone or with immunotherapy and the potential toxicities associated with each dosing scheme. MTR OralGem restricted tumor angiogenesis by regulating thrombospondin-1 (TSP-1) and vascular endothelial growth factor A (VEGFA) expression. MTR OralGem enhanced antitumor immunity by increasing T effector responses and cytokine release, concomitant with dampening regulatory T cell populations. Promising pharmacokinetic properties afforded minimized blood and thymus toxicity and favorable bioavailability upon MTR administration compared to MTD. The combination of MTR OralGem with immunotherapy was shown to be highly efficacious and tolerable, illuminating it as a strong candidate therapeutic scheme for the treatment of NSCLC. [ABSTRACT FROM AUTHOR]

Simple Summary: 5-Fluorouracil (5-FU) is a chemotherapy drug that can cause severe toxicity in some patients. A protein, an action molecule in our cells, called dihydropyrimidine dehydrogenase, or DPD for short, is important in clearing 5-FU from the body. Some people have versions of DPD that do not clear 5-FU very well. This causes active drug to stay in the body too long, causing toxicities such as diarrhoea or low levels of blood cells important for fighting infections. Current guidelines identify four sequence changes in the gene that encodes DPD with high level evidence of an impact on protein activity. Our study aims to calculate the frequency of a set of variants identified in patients with DPD deficiency in patients that were part of a clinical trial called QUASAR 2. We go on to test how well the DPD deficiency variants and a set of common variants previously shown to be associated with 5-FU toxicity can predict a person's risk of 5-Fluorouracil induced toxicity. Our research is important for working out the best way to identify patients at risk of toxicity so high risk patients can be given lower doses of 5-Fluorouracil or be treated with a different drug all together. Efficacy of 5-Fluorouracil (5-FU)-based chemotherapy is limited by significant toxicity. Tests based upon variants in the Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines with high level evidence of a link to dihydropyrimidine dehydrogenase (DPD) phenotype and 5-FU toxicity are available to identify patients at high risk of severe adverse events (AEs). We previously reported associations between rs1213215, rs2612091, and NM_000110.3:c.1906-14763G>A (rs12022243) and capecitabine induced toxicity in clinical trial QUASAR 2. We also identified patients with DPD deficiency alleles NM_000110.3: c.1905+1G>A, NM_000110.3: c.2846C>T, NM_000110.3:c.1679T>G and NM_000110.3:c.1651G>A. We have now assessed the frequency of thirteen additional DPYD deficiency variants in 888 patients from the QUASAR 2 clinical trial. We also compared the area under the curve (AUC)—a measure of diagnostic accuracy—of the high-level evidence variants from the CPIC guidelines plus and minus additional DPYD deficiency variants and or common variants associated with 5-FU toxicity. Including additional DPYD deficiency variants retained good diagnostic accuracy for serious adverse events (AEs) and improved sensitivity for predicting grade 4 haematological toxicities (sensitivity 0.75, specificity 0.94) but the improvement in AUC for this toxicity was not significant. Larger datasets will be required to determine the benefit of including additional DPYD deficiency variants not observed here. Genotyping two common alleles statistically significantly improves AUC for prediction of risk of HFS and may be clinically useful (AUC difference 0.177, sensitivity 0.84, specificity 0.31). [ABSTRACT FROM AUTHOR]

Simple Summary: Several chemotherapy drugs are approved for ovarian cancer treatment in the neo-adjuvant/adjuvant setting as well as following relapse. These include carboplatin, paclitaxel, doxorubicin, topotecan, PARP inhibitors (PARPi), and gemcitabine. However, except for PAPRi, there are no predictive biomarkers to guide the choice of drug. The majority of chemotherapeutic drugs function by inducing DNA damage or inhibiting its repair. However, the association of DNA damage repair (DDR) pathway alterations with therapy response remain unclear. In this study, using a panel of 14 ovarian cancer cell lines, 10 patient ascites-derived primary cultures and bioinformatic analysis of The Cancer Genome Atlas (TCGA) ovarian cancer dataset, we identified the role of genomic/transcriptomic and/or functional alterations in DDR pathways as determinants of therapy response. Defective DNA damage response (DDR) pathways are enabling characteristics of cancers that not only can be exploited to specifically target cancer cells but also can predict chemotherapy response. Defective Homologous Recombination Repair (HRR) function, e.g., due to BRCA1/2 loss, is a determinant of response to platinum agents and PARP inhibitors in ovarian cancers. Most chemotherapies function by either inducing DNA damage or impacting on its repair but are generally used in the clinic unselectively. The significance of HRR and other DDR pathways in determining response to several other chemotherapy drugs is not well understood. In this study, the genomic, transcriptomic and functional analysis of DDR pathways in a panel of 14 ovarian cancer cell lines identified that defects in DDR pathways could determine response to several chemotherapy drugs. Carboplatin, rucaparib, and topotecan sensitivity were associated with functional loss of HRR (validated in 10 patient-derived primary cultures) and mismatch repair. Two DDR gene expression clusters correlating with treatment response were identified, with PARP10 identified as a novel marker of platinum response, which was confirmed in The Cancer Genome Atlas (TCGA) ovarian cancer cohort. Reduced non-homologous end-joining function correlated with increased sensitivity to doxorubicin, while cells with high intrinsic oxidative stress showed sensitivity to gemcitabine. In this era of personalised medicine, molecular/functional characterisation of DDR pathways could guide chemotherapy choices in the clinic allowing specific targeting of ovarian cancers. [ABSTRACT FROM AUTHOR]

Simple Summary: The first core tip of this study is that we summarized the experience of conversion therapy of intrahepatic cholangiocarcinoma (IHCC) in a single center and found conversion therapy could provide a significant improvement in the overall survival of patients with IHCC. Previous studies mainly focused on case reports and case series, and our research provided more evidence for the efficacy of conversion therapy in IHCC. The second is that we established the organoid of IHCC for drug screening and firstly verified the results of drug screening tests in cancer organoid were consistent with the levels of efficacy observed in the patient from whom it was derived. Cancer organoid is a promising technology for conversion therapy according to our study but more organoids are still needed. This study was performed to determine the efficacy of conversion therapy in intrahepatic cholangiocarcinoma (IHCC) and explore the feasibility of cancer organoid to direct the conversion therapy of IHCC. Patient data were retrospectively reviewed in this study and cancer organoids were established using tissues obtained from two patients. A total of 42 patients with IHCC received conversion therapy, 9 of whom were downstaged successfully, and another 157 patients were initially resectable. Kaplan–Meier curves showed that the successfully downstaged patients had a significantly improved overall survival compared to those in whom downstaging was unsuccessful (p = 0.017), and had a similar overall survival to that of initially resectable patients (p = 0.965). The IHCC organoid was successfully established from one of two obtained tissues. Routine hematoxylin and eosin staining and immunohistological staining found the organoid retained the histopathological characteristics of the original tissues. Whole exome sequencing results indicated the IHCC organoid retained appropriately 87% of the variants in the original tissue. Gemcitabine and paclitaxel exhibited the strongest inhibitory effects on the cancer organoid as determined using drug screening tests, consistent with the levels of efficacy observed in the patient from whom it was derived. This study indicates that conversion therapy could improve the survival of patients with IHCC despite its low success rate, and it may be directed by cancer organoids though this is merely a proof of feasibility. [ABSTRACT FROM AUTHOR]

Simple Summary: The great majority, more than 90%, of patients with pancreatic ductal adenocarcinoma (PDAC) die within less than five years after detection of the disease, despite recent treatment advances. The poor prognosis is related to late diagnosis, aggressive disease progression, and tumor resistance to conventional chemotherapy. PDAC tumor tissue is characterized by dense fibrosis and poor nutrient availability. A large portion of the tumor is made up of stromal fibroblasts, the pancreatic stellate cells (PSCs), which are known to contribute to tumor progression in several ways. PSCs have been shown to act as an alternate energy source, induce drug resistance, and inhibit drug availability in tumor cells, however, the underlying exact molecular mechanisms remain unknown. In this literature review, we discuss recent available knowledge about the contributions of PSCs to the overall progression of PDAC via changes in tumor metabolism and how this is linked to therapy resistance. Pancreatic ductal adenocarcinoma (PDAC), also known as pancreatic cancer (PC), is characterized by an overall poor prognosis and a five-year survival that is less than 10%. Characteristic features of the tumor are the presence of a prominent desmoplastic stromal response, an altered metabolism, and profound resistance to cancer drugs including gemcitabine, the backbone of PDAC chemotherapy. The pancreatic stellate cells (PSCs) constitute the major cellular component of PDAC stroma. PSCs are essential for extracellular matrix assembly and form a supportive niche for tumor growth. Various cytokines and growth factors induce activation of PSCs through autocrine and paracrine mechanisms, which in turn promote overall tumor growth and metastasis and induce chemoresistance. To maintain growth and survival in the nutrient-poor, hypoxic environment of PDAC, tumor cells fulfill their high energy demands via several unconventional ways, a process generally referred to as metabolic reprogramming. Accumulating evidence indicates that activated PSCs not only contribute to the therapy-resistant phenotype of PDAC but also act as a nutrient supplier for the tumor cells. However, the precise molecular links between metabolic reprogramming and an acquired therapy resistance in PDAC remain elusive. This review highlights recent findings indicating the importance of PSCs in aiding growth-permissive metabolic reprogramming and gemcitabine chemoresistance in PDAC. [ABSTRACT FROM AUTHOR]

Simple Summary: Pancreatic ductal adenocarcinoma is a devastating disease. Using modern technique of radiotherapy, such as proton therapy, may simultaneously enhance dose to the tumor and decrease dose to surrounding organ, thus limiting toxicity. Moreover, associating drugs to radiotherapy also increases its effectiveness on tumor. The aim of our study was to show the benefit of proton therapy compared to standard radiotherapy with photon, and the benefit of associating different drugs with those particles in vivo. Thus, our results displayed a higher effectiveness of associating proton therapy, gemcitabine and olaparib. Finally, we pointed out that treatment induced significant transcriptomic alterations. Over the past few years, studies have focused on the development of targeted radiosensitizers such as poly(ADP-ribose) polymerase inhibitors. We performed an in vivo study and a whole-transcriptome analysis to determine whether PARP inhibition enhanced gemcitabine-based chemoradiosensitization of pancreatic cancer xenografts, combined with either proton or photon irradiation. NMRI mice bearing MIA PaCa-2 xenografts were treated with olaparib and/or gemcitabine and irradiated with 10 Gy photon or proton. First, a significant growth inhibition was obtained after 10 Gy proton irradiation compared to 10 Gy photon irradiation (p = 0.046). Moreover, the combination of olaparib, gemcitabine and proton therapy significantly sensitized tumor xenografts, compared to gemcitabine (p = 0.05), olaparib (p = 0.034) or proton therapy (p < 0.0001) alone or to the association of olaparib, gemcitabine and radiotherapy (p = 0.024). Simultaneously, whole RNA sequencing profiling showed differentially expressed genes implicated in categories such as DNA repair, type I interferon signaling and cell cycle. Moreover, a large amount of lncRNA was dysregulated after proton therapy, gemcitabine and olaparib. This is the first study showing that addition of olaparib to gemcitabine-based chemoradiotherapy improved significantly local control in vivo, especially after proton therapy. RNA sequencing profiling analysis presented dynamic alteration of transcriptome after chemoradiation and identified a classifier of gemcitabine response. [ABSTRACT FROM AUTHOR]

Simple Summary: Pancreatic ductal adenocarcinoma (PDAC, also known as pancreatic cancer) is one of the deadliest tumor types, characterized by poor prognosis, profound chemoresistance and overall low survival. Gemcitabine remains the standard of care for all stages of PDAC, however, with poor clinical benefits which is considered to be due to reduced drug availability in tumor cells. Gemcitabine-induced cytotoxicity depends upon sufficient drug uptake followed by intracellular activation. Pancreatic stellate cells (PSCs), a major stromal component of PDAC, were recently reported to scavenge active metabolites of gemcitabine, thereby making it unavailable for cancer cells. Gemcitabine uptake and processing in both tumor cells and PSCs, as well as expression analysis of its molecular metabolic regulators, was investigated in this study. We observed heterogeneous gemcitabine-induced cytotoxicity in different pancreatic cancer cells whereas it was absent in PSCs. The gemcitabine-induced cytotoxicity in pancreatic cancer cells was driven by differential expression of its molecular regulators. Gemcitabine resistance in pancreatic ductal adenocarcinoma (PDAC) is attributed to cancer cell-intrinsic drug processing and the impact of the tumor microenvironment, especially pancreatic stellate cells (PSCs). This study uses human PDAC-derived paired primary cancer cells (PCCs) and PSCs from four different tumors, and the PDAC cell lines BxPC-3, Mia PaCa-2, and Panc-1, to assess the fate of gemcitabine by measuring its cellular uptake, cytotoxicity, and LC-MS/MS-based metabolite analysis. Expression analysis and siRNA-mediated knockdown of key regulators of gemcitabine (hENT1, CDA, DCK, NT5C1A) was performed. Compared to PSCs, both the paired primary PCCs and cancer cell lines showed gemcitabine-induced dose-dependent cytotoxicity, high uptake, as well as high and variable intracellular levels of gemcitabine metabolites. PSCs were gemcitabine-resistant and demonstrated significantly lower drug uptake, which was not influenced by co-culturing with their paired PCCs. Expression of key gemcitabine regulators was variable, but overall strong in the cancer cells and significantly lower or undetectable in PSCs. In cancer cells, hENT1 inhibition significantly downregulated gemcitabine uptake and cytotoxicity, whereas DCK knockdown reduced cytotoxicity. In conclusion, heterogeneity in gemcitabine processing among different pancreatic cancer cells and stellate cells results from the differential expression of molecular regulators which determines the effect of gemcitabine. [ABSTRACT FROM AUTHOR]