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Purpose There are no reliable biomarkers to guide treatment for patients with borderline resectable pancreatic cancer (BRPC) in the neoadjuvant setting. We used plasma circulating tumor DNA (ctDNA) sequencing to search biomarkers for patients with BRPC receiving neoadjuvant mFOLFIRINOX in our phase 2 clinical trial (NCT02749136). Materials and Methods Among the 44 patients enrolled in the trial, patients with plasma ctDNA sequencing at baseline or postoperation were included in this analysis. Plasma cell-free DNA isolation and sequencing were performed using the Guardant 360 assay. Detection of genomic alterations, including DNA damage repair (DDR) genes, were examined for correlations with survival. Results Among the 44 patients, 28 patients had ctDNA sequencing data qualified for the analysis and were included in this study. Among the 25 patients with baseline plasma ctDNA data, 10 patients (40%) had alterations of DDR genes detected at baseline, including ATM, BRCA1, BRCA2 and MLH1, and showed significantly better progression-free survival than those without such DDR gene alterations detected (median, 26.6 vs. 13.5 months; log-rank p=0.004). Patients with somatic KRAS mutations detected at baseline (n=6) had significantly worse overall survival (median, 8.5 months vs. not applicable; log-rank p=0.003) than those without. Among 13 patients with post-operative plasma ctDNA data, eight patients (61.5%) had detectable somatic alterations. Conclusion Detection of DDR gene mutations from plasma ctDNA at baseline was associated with better survival outcomes of patients with borderline resectable pancreatic ductal adenocarcinoma treated with neoadjuvant mFOLFIRINOX and may be a prognostic biomarker. [ABSTRACT FROM AUTHOR]

Purpose The benefit of adjuvant chemotherapy following curative-intent surgery in pancreatic ductal adenocarcinoma (PDAC) patients who had received neoadjuvant FOLFIRINOX is unclear. This study aimed to assess the survival benefit of adjuvant chemotherapy in this patient population. Materials and Methods This retrospective study included 218 patients with localized non-metastatic PDAC who received neoadjuvant FOLFIRINOX and underwent curative-intent surgery (R0 or R1) between January 2017 and December 2020. The association of adjuvant chemotherapy with disease-free survival (DFS) and overall survival (OS) was evaluated in overall patients and in the propensity score matched (PSM) cohort. Subgroup analysis was conducted according to the pathology-proven lymph node status. Results Adjuvant chemotherapy was administered to 149 patients (68.3%). In the overall cohort, the adjuvant chemotherapy group had significantly improved DFS and OS compared to the observation group (DFS: median, 13.8 months [95% confidence interval (CI), 11.0 to 19.1] vs. 8.2 months [95% CI, 6.5 to 12.0]; p < 0.001; and OS: median, 38.0 months [95% CI, 32.2 to not assessable] vs. 25.7 months [95% CI, 18.3 to not assessable]; p=0.005). In the PSM cohort of 57 matched pairs of patients, DFS and OS were better in the adjuvant chemotherapy group than in the observation group (p < 0.001 and p=0.038, respectively). In the multivariate analysis, adjuvant chemotherapy was a significant favorable prognostic factor (vs. observation; DFS: hazard ratio [HR], 0.51 [95% CI, 0.36 to 0.71; p < 0.001]; OS: HR, 0.45 [95% CI, 0.29 to 0.71; p < 0.001]). Conclusion Among PDAC patients who underwent surgery following neoadjuvant FOLFIRINOX, adjuvant chemotherapy may be associated with improved survival. Randomized studies should be conducted to validate this finding. [ABSTRACT FROM AUTHOR]

Purpose Biliary tract cancers (BTCs) are rare and show a dismal prognosis with limited treatment options. To improve our understanding of these heterogeneous tumors and develop effective therapeutic agents, suitable preclinical models reflecting diverse tumor characteristics are needed. We established and characterized new patient-derived cancer cell cultures and patient-derived xenograft (PDX) models using malignant ascites from five patients with BTC. Materials and Methods Five patient-derived cancer cell cultures and three PDX models derived from malignant ascites of five patients with BTC, AMCBTC-01, -02, -03, -04, and -05, were established. To characterize the models histogenetically and confirm whether characteristics of the primary tumor were maintained, targeted sequencing and histopathological comparison between primary tissue and xenograft tumors were performed. Results From malignant ascites of five BTC patients, five patient-derived cancer cell cultures (100% success rate), and three PDXs (60% success rate) were established. The morphological characteristics of three primary xenograft tumors were compared with those of matched primary tumors, and they displayed a similar morphology. The mutated genes in samples (models, primary tumor tissue, or both) from more than one patient were TP53 (n=2), KRAS (n=2), and STK11 (n=2). Overall, the pattern of commonly mutated genes in BTC cell cultures was different from that in commercially available BTC cell lines. Conclusion We successfully established the patient-derived cancer cell cultures and xenograft models derived from malignant ascites in BTC patients. These models accompanied by different genetic characteristics from commercially available models will help better understand BTC biology. [ABSTRACT FROM AUTHOR]

Exosomes are nanosized extracellular vesicles secreted by various cell types, including those of the immune system, such as natural killer (NK) cells. They play a role in intercellular communication by transporting signal molecules between the cells. Recent studies have reported that NK cell-derived exosomes (NK-exo) contain cytotoxic proteins-induced cell death. However, the characteristics and potential functions of NK-exo, especially for the liver cancer are poorly understood. In this study, we investigated the anti-tumor effects of NK-exo in the primary liver cancer, hepatocellular carcinoma (HCC), using the orthotopic and subcutaneous tumor model. We found that NK-exo expressed both typical exosomal markers (e.g. CD63, CD81, and Alix) and cytotoxic proteins (e.g. perforin, granzyme B, FasL, and TRAIL). NK-exo were selectively taken up by HCC cells (e.g. Hep3B, HepG2, and Huh 7). Interestingly, Hep3B cells induced the highest cytotoxicity compared with HepG2 and Huh7 cells, and substantially enhanced the apoptosis by NK-exo. Furthermore, we demonstrated that NK-exo inhibited the phosphorylation of serine/threonine protein kinases (e.g. AKT and ERK1/2), and enhanced the activation of specific apoptosis markers (e.g. caspase-3, -7, -8, -9, and PARP) in Hep3B cells. NK-exo also exhibit the active targeting ability and potent therapeutic effects in both orthotopic and subcutaneous HCC mouse models. Overall, these results suggest that NK-exo indicate strong anti-tumor effects in HCC, which are mediated by novel regulatory mechanisms involved in serine/threonine kinase pathway-associated cell proliferation and caspase activation pathway-associated apoptosis. [ABSTRACT FROM AUTHOR]

Background: The optimal prognostic markers for neoadjuvant chemotherapy in patients with borderline resectable or locally advanced pancreatic cancer are not yet established. Method: Patients who received neoadjuvant chemotherapy prior to surgery and underwent FDG-PET/CT between July 2012 and December 2017 were included. Metabolic parameters including standardized uptake value (SUV), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) on PET/CT, and response evaluations using PERCIST criteria, were investigated for its impact on survival and recurrence. Cox proportional hazards model was performed. Differences in risk were expressed as hazard ratio (HR) with 95 per cent confidence interval. Results: The patients with borderline resectable (N=106) or locally advanced pancreatic cancer (N=82) were identified. The median survival was 33.6months. Decreased metabolic parameters of PET/CT after neoadjuvant chemotherapy were associated with positive impacts on survival and recurrence such as SUVmax (HR 1.16, 95 per cent c.i. 1.01 to 1.32, P=0.025), SUVpeak (HR 1.26, 95 per cent c.i. 1.05 to 1.51, P=0.011), and MTV (HR 1.15, 95 per cent c.i. 1.04 to 1.26, P=0.005). Large delta values were related to a positive impact on recurrence such as SUVmax (HR 1.21, 95 per cent c.i. 1.06 to 1.38, P=0.005). Post-neoadjuvant chemotherapy SUVmax -3 (HR 3.46, 95 per cent c.i. 1.21 to 9.91; P=0.036) was an independent prognostic factor for negative impact on survival. Patients with postneoadjuvant chemotherapy SUVmax <3 showed more chemotherapy cycles (8.7 versus 6.2, P=0.001), more frequent complete metabolic response (25 versus 2.2 per cent, P=0.002), smaller tumour size (2.1 versus 3.1 cm, P=0.002), and less frequent lymphovascular invasion (23.7 versus 51.1 per cent, P=0.020) than patients with SUVmax -3. Conclusion: Reduction in metabolic tumour parameters of FDG-PET/CT after neoadjuvant chemotherapy indicates improved overall survival and recurrence-free survival. [ABSTRACT FROM AUTHOR]

Purpose This study evaluated the efficacy of adjuvant chemotherapy (AC) in patients with resected ampulla of Vater (AoV) carcinoma. Materials and Methods Data from 646 patients who underwent surgical resection at Asan Medical Center between 2000 and 2017 were retrospectively reviewed. Results The median age of the patients was 62 years, and 54.2% were male. Patients were classified into AC group (n=165, 25.5%) and no AC group (n=481, 74.5%). With a median follow-up duration of 88 months, in patients with stage I, II, III, median recurrencefree survival (RFS) was not reached, 44 months, and 15 months, respectively, and the median overall survival (OS) were not reached, 88 months and 35 months, respectively. Despite no statistical significance, RFS and OS were better in stage II patients with AC than in those without AC (median RFS, 151 months vs. 38 months; p=0.156 and median OS, 153 months vs. 74 months; p=0.299). In multivariate analysis for RFS and OS, TNM stage, R1 resection status, presence of lymphovascular invasion, and perineural invasion remained significant factors, whereas AC (hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.54 to 1.00; p=0.052) was marginally related with RFS. After propensity score matching in only stage II/III patients, RFS and OS with AC were numerically longer than those without AC (HR, 0.80; 95% CI, 0.60 to 1.06; p=0.116 and HR, 0.77; 95% CI, 0.56 to 1.06; p=0.111). Conclusion AC with fluoropyrimidine did not improve survival of patients with resected AoV carcinoma. However, multivariate analysis with prognostic factors showed a marginally significant survival benefit with AC. [ABSTRACT FROM AUTHOR]

Purpose The clinical implications of tumor-infiltrating T cell subsets and their spatial distribution in biliary tract cancer (BTC) patients treated with gemcitabine plus cisplatin were investigated. Materials and Methods A total of 52 BTC patients treated with palliative gemcitabine plus cisplatin were included. Multiplexed immunohistochemistry was performed on tumor tissues, and immune infiltrates were separately analyzed for the stroma, tumor margin, and tumor core. Results The density of CD8+ T cells, FoxP3- CD4+ helper T cells, and FoxP3+ CD4+ regulatory T cells was significantly higher in the tumor margin than in the stroma and tumor core. The density of LAG3- or TIM3-expressing CD8+ T cell and FoxP3- CD4+ helper T cell infiltrates was also higher in the tumor margin. In extrahepatic cholangiocarcinoma, there was a higher density of T cell subsets in the tumor core and regulatory T cells in all regions. A high density of FoxP3- CD4+ helper T cells in the tumor margin showed a trend toward better progression-free survival (PFS) (p=0.092) and significantly better overall survival (OS) (p=0.012). In multivariate analyses, a high density of FoxP3- CD4+ helper T cells in the tumor margin was independently associated with favorable PFS and OS. Conclusion The tumor margin is the major site for the active infiltration of T cell subsets with higher levels of LAG3 and TIM3 expression in BTC. The density of tumor margin-infiltrating FoxP3- CD4+ helper T cells may be associated with clinical outcomes in BTC patients treated with gemcitabine plus cisplatin. [ABSTRACT FROM AUTHOR]

The present study aimed to compare the pattern of distant recurrence between patients with non-metastatic rectal cancer treated with pre-operative (OP) and those treated with post-operative (post-OP) chemoradiotherapy (CRT). A total of 631 patients with newly diagnosed non-metastatic rectal cancer who had received pre-OP or post-OP CRT with curative intent surgery between August 2008 and April 2015 were identified. Inverse probability of treatment weighting (IPTW) was performed to account for baseline differences between the two arms. Overall, 449 and 182 patients were treated with pre-OP and post-OP CRT, respectively. Sex, tumor location, clinical tumor stage, CRT regimen and adjuvant chemotherapy regimen were significantly different between the two arms. The median follow-up duration was 55.4 months (range, 53.7-57.1). The 5-year distant recurrence-free survival (RFS) rates and 5-year overall survival (OS) rates were not significantly different between the pre-OP and post-OP CRT arms (RFS, 67.5 vs. 71.6%, P=0.595 and OS, 81.9 vs. 77.0%, P=0.449), and no difference was observed in the distant recurrence patterns. Following IPTW, there was still no difference in distant RFS (pre-OP vs. post-OP CRT; hazard ratio (HR)=0.62; P=0.911), but pre-OP CRT was significantly associated with lower peritoneal recurrence (pre-OP vs. post-OP CRT; HR, 0.13; P=0.032). In addition, there was no significant difference in OS between the two arms (pre-OP vs. post-OP CRT; HR, 0.85; P=0.665). In conclusion, although distant RFS was not significantly different between the two arms, pre-OP CRT was significantly associated with a lower risk of peritoneal recurrence than post-OP CRT in patients non-metastatic rectal cancer. [ABSTRACT FROM AUTHOR]

Purpose The current standard chemotherapy for advanced biliary tract cancer (BTC) has limited benefit, and novel therapies need to be investigated. Materials and Methods In this prospective cohort study, programmed death ligand-1 (PD-L1)--positive BTC patients who progressed on first-line gemcitabine plus cisplatin were enrolled. Pembrolizumab 200 mg was administered intravenously every 3 weeks. Results Between May 2018 and February 2019, 40 patients were enrolled. Pembrolizumab was given as second-line (47.5%) or ≤ third-line therapy (52.5%). The objective response rate was 10% and 12.5% by Response Evaluation Criteria in Solid Tumor (RECIST) v1.1 and immune-modified RECIST (imRECIST) and median duration of response was 6.3 months. Among patients with progressive disease as best response, one patient (1/20, 5.0%) achieved complete response subsequently. The median progression-free survival (PFS) and overall survival (OS) were 1.5 months (95% confidence interval [CI], 0.0 to 3.0) and 4.3 months (95% CI, 3.5 to 5.1), respectively, and objective response per imRECIST was significantly associated with PFS (p < 0.001) and OS (p=0.001). Tumor proportion score ≥ 50% was significantly associated with higher response rates including the response after pseudoprogression (vs. < 50%; 37.5% vs. 6.5%; p=0.049). Conclusion Pembrolizumab showed modest anti-tumor activity in heavily pretreated PD-L1--positive BTC patients. In patients who showed objective response, durable response could be achieved. [ABSTRACT FROM AUTHOR]

Background/Aim: The aim of this study was to examine the efficacy and safety of direct oral anticoagulants for cancer-associated venous thromboembolism (VTE) in patients with active cancer . Patients and Methods: This study included patients with advanced unresectable/metastatic upper gastrointestinal (GI) or hepatopancreatobiliary (HPB) cancers with high risks of VTE and bleeding. Results: No significant differences were noted in potential bleeding factors between the rivaroxaban (n=105) and low-molecular-weight heparin (LMWH) (n=69) groups. Rivaroxaban exhibited similar risk of recurrent/aggravated VTE compared with LMWH (p=0.625) but increased risk of major bleeding (17.4% vs. 7.6%; p=0.072), clinically relevant bleeding (31.9% vs. 14.3%; p=0.019), and total bleeding (40.6% vs. 19%; p=0.010). The multivariate analysis regarded rivaroxaban as a significant factor for major bleeding (p=0.043) and clinically relevant bleeding (p=0.043). Conclusion: Rivaroxaban exhibits comparable efficacy but increases bleeding risks compared with LMWH in patients with active unresectable/metastatic upper GI tract or HPB cancers, requiring extra caution of higher major bleeding risks. [ABSTRACT FROM AUTHOR]

Purpose Since the introduction of nab-paclitaxel plus gemcitabine (nab-P+GEM) as first-line (1L) treatment for metastatic pancreatic adenocarcinoma (mPDAC), optimal second-line (2L) chemotherapy after progression is unclear. We assessed clinical outcomes of 2L chemotherapy for disease that progressed on 1L nab-P+GEM. Materials and Methods Among the 203 patients previously treated with 1L nab-P+GEM for mPDAC at Asan Medical Center, between February and December 2016, records of 120 patients receiving 2L chemotherapy after progression on nab-P+GEM were retrospectively reviewed. The response rate and survival were evaluated along with analysis of prognostic factors. Results Fluoropyrimidine-oxaliplatin doublets (FOLFOX or XELOX) were used in 78 patients (65.0%), fluoropyrimidine monotherapy in 37 (30.8%), and liposomal irinotecan plus fluorouracil in two (1.7%). The median progression-free survival (PFS) and overall survival (OS) were 3.29 months and 7.33 months from the start of 2L therapy. Fluoropyrimidine-oxaliplatin regimens and fluoropyrimidine monotherapy did not yield significantly different median PFS (2.89 months vs. 3.81 months, p=0.40) or OS (7.04 months vs. 7.43 months, p=0.86). A high neutrophil-lymphocyte ratio (> 2.2) and a short time to progression with 1L nab-P+GEM (< 6.4 months) were independent prognostic factors of poor OS with 2L therapy. Conclusion 2L fluoropyrimidine-oxaliplatin doublets and fluoropyrimidine monotherapy after failure of 1L nab-P+GEM had modest efficacy, with no differences in treatment outcomes between them. Further investigation is warranted for the optimal 2L chemo-regimens and sequencing of systemic chemotherapy for patients with mPDAC. [ABSTRACT FROM AUTHOR]

Purpose Stereotactic body radiation therapy (SBRT) is a promising treatment modality for locally advanced pancreatic cancer (LAPC). We evaluated the clinical outcomes of SBRT in patients with LAPC. Patients and methods We retrospectively analyzed the medical records of patients with LAPC who underwent SBRT at our institution between April 2011 and July 2016. Fiducial markers were implanted using endoscopic ultrasound guidance one week prior to 4-dimensional computed tomography (CT) simulation and daily cone beam CT was used for image guidance. Patients received volumetric modulated arc therapy or intensity modulated radiotherapy using respiratory gating technique. A median dose of 28 Gy (range, 24–36 Gy) was given over four consecutive fractions delivered within one week. Survival outcomes including freedom from local disease progression (FFLP), progression-free survival (PFS), and overall survival (OS) were analyzed. Acute and late toxicities related to SBRT were assessed. Results A total of 95 patients with LAPC were analyzed, 52 of which (54.7%) had pancreatic head cancers. Most (94.7%) had received gemcitabine-based chemotherapy. The 1-year FFLP rate was 80.1%. Median OS and PFS were 16.7 months and 10.2 months, respectively; the 1-year OS and PFS rates were 67.4% and 42.9%, respectively. Among 79 patients who experienced failure, the sites of first failures were isolated local progressions in 12 patients (15.2%), distant metastasis in 55 patients (69.6%), and both in 12 patients (15.2%). Seven patients (7.4%) were able to undergo surgical resection after SBRT and four had marginnegative resections. Three patients (3.2%) had grade 3 nausea/vomiting during SBRT, and late grade 3 toxicity was observed in another three patients. Conclusions LAPC patients who received chemotherapy and SBRT had favorable FFLP and OS with minimal treatment-related toxicity. The most common pattern of failure was distant metastasis, which warrants further studies on the optimal scheme of chemotherapy and SBRT. [ABSTRACT FROM AUTHOR]

Purpose Although gemcitabine plus cisplatin has been established as the standard first-line chemotherapy for patients with advanced biliary tract cancer (BTC), overall prognosis remains poor. We investigated the efficacy of a novel triplet combination of oxaliplatin, irinotecan, and S-1 (OIS) for advanced BTC. Materials and Methods Chemotherapy-naive patients with histologically documented unresectable or metastatic BTC were eligible for this multicenter, single-arm phase II study. Patients received 65 mg/m2 oxaliplatin (day 1), 135 mg/m2 irinotecan (day 1), and 40 mg/m2 S-1 (twice a day, days 1-7) every 2 weeks. Primary endpoint was objective response rate. Targeted exome sequencing for biomarker analysis was performed using archival tissue. Results In total, 32 patients were enrolled between October 2015 and June 2016. Median age was 64 years (range, 40 to 76 years), with 24 (75%) male patients; 97% patients had metastatic or recurrent disease. Response rate was 50%, and median progression-free survival and overall survival (OS) were 6.8 months (95% confidence interval [CI], 4.8 to 8.8) and 12.5 months (95% CI, 7.0 to 18.0), respectively. The most common grade 3-4 adverse events were neutropenia (32%), diarrhea (6%), and peripheral neuropathy (6%). TP53 and KRAS mutations were the most frequent genomic alterations (42% and 32%, respectively), and KRAS mutations showed a marginal relationship with worse OS (p=0.07). Conclusion OIS combination chemotherapy was feasible and associated with favorable efficacy outcomes as a first-line treatment in patients with advanced BTC. Randomized studies are needed to compare OIS with gemcitabine plus cisplatin. [ABSTRACT FROM AUTHOR]

Purpose Pancreatic cancer associated double primary tumors are rare and their clinicopathologic characteristics are not well elucidated. Materials and Methods Clinicopathologic factors of 1,352 primary pancreatic cancers with or without associated double primary tumors were evaluated. Results Of resected primary pancreatic cancers, 113 (8.4%) had associated double primary tumors, including 26 stomach, 25 colorectal, 18 lung, and 13 thyroid cancers. The median interval between the diagnoses of pancreatic cancer and associated double primary tumors was 0.5 months. Overall survival (OS) of pancreatic cancer patients with associated double primary tumors was longer than those with pancreatic cancer only (median, 23.1 months vs. 17.0 months; p=0.002). Patients whose pancreatic cancers were resected before the diagnosis of metachronous tumors had a better OS than patients whose pancreatic cancer resected after the diagnosis of metachronous tumors (48.9 months and 13.5 months, p=0.001) or those whose pancreatic cancers were resected synchronously with non-pancreas tumors (19.1 months, p=0.043). The OS of pancreatic cancer patients with stomach (33.9 months, p=0.032) and thyroid (117.8 months, p=0.049) cancers was significantly better than those with pancreas cancer only (17.0 months). Conclusion About 8% of resected pancreatic cancers had associated double primary tumors, and those from the colorectum, stomach, lung, and thyroid were common. Patients whose pancreatic cancer was resected before the diagnosis of metachronous tumors had better OS than those resected after the diagnosis of metachronous tumors or those resected synchronously. [ABSTRACT FROM AUTHOR]

Background: In metastatic colorectal cancer, the location of the primary tumor has been suggested to have biological significance. In this study, we investigated whether primary tumor location affects cetuximab efficacy in patients with RAS wild-type metastatic colorectal cancer.Methods: Genotyping by the SequenomMassARRAY technology platform (OncoMap) targeting KRAS, NRAS, PIK3CA, and BRAF was performed in tumors from 307 patients who had been given cetuximab as salvage treatment. Tumors with mutated RAS (KRAS or NRAS; n = 127) and those with multiple primary location (n = 10) were excluded. Right colon cancer was defined as a tumor located in the proximal part to splenic flexure.Results: A total of 170 patients were included in the study (right versus left, 23 and 147, respectively). Patients with right colon cancer showed more mutated BRAF (39.1% vs. 5.4%), mutated PIK3CA (13% vs. 1.4%), poorly differentiated tumor (17.4% vs. 3.4%), and peritoneal involvement (26.1% vs. 8.8%) than those with left colon and rectal cancer. Right colon cancer showed poorer progression-free survival (2.0 vs.5.0 months, P = 0.002) and overall survival (4.1 months and 13.0 months, P < 0.001) than the left colon and rectal cancer. By multivariable analysis, BRAF mutation, right colon primary, poorly differentiated histology, and peritoneal involvement were associated with risk of death.Conclusions: In RAS wild-type colon cancer treated with cetuximab as salvage treatment, right colon primary was associated with poorer survival outcomes than left colon and rectal cancer. [ABSTRACT FROM AUTHOR]

Background: In metastatic colorectal cancer, the location of the primary tumor has been suggested to have biological significance. In this study, we investigated whether primary tumor location affects cetuximab efficacy in patients with RAS wild-type metastatic colorectal cancer. Methods: Genotyping by the SequenomMassARRAY technology platform (OncoMap) targeting KRAS, NRAS, PIK3CA, and BRAF was performed in tumors from 307 patients who had been given cetuximab as salvage treatment. Tumors with mutated RAS (KRAS or NRAS; n = 127) and those with multiple primary location (n = 10) were excluded. Right colon cancer was defined as a tumor located in the proximal part to splenic flexure. Results: A total of 170 patients were included in the study (right versus left, 23 and 147, respectively). Patients with right colon cancer showed more mutated BRAF (39.1% vs. 5.4%), mutated PIK3CA (13% vs. 1.4%), poorly differentiated tumor (17.4% vs. 3.4%), and peritoneal involvement (26.1% vs. 8.8%) than those with left colon and rectal cancer. Right colon cancer showed poorer progression-free survival (2.0 vs.5.0 months, P = 0.002) and overall survival (4.1 months and 13.0 months, P < 0.001) than the left colon and rectal cancer. By multivariable analysis, BRAF mutation, right colon primary, poorly differentiated histology, and peritoneal involvement were associated with risk of death. Conclusions: In RAS wild-type colon cancer treated with cetuximab as salvage treatment, right colon primary was associated with poorer survival outcomes than left colon and rectal cancer. [ABSTRACT FROM AUTHOR]

Background: Pancreatic ductal adenocarcinomas are among the most malignant neoplasms and have very poor prognosis. Our understanding of various cancers has recently improved the survival of patients with cancer, except for pancreatic cancers. Establishment of primary cancer cell lines of pancreatic ductal adenocarcinomas will be useful for understanding the molecular mechanisms of this disease. Methods: Eighty-one surgically resected pancreatic ductal adenocarcinomas were collected. Six novel pancreatic cancer cell lines, AMCPAC01-06, were established and histogenetic characteristics were compared with their matched tissues. The clinicopathologic and molecular characteristics of the cell lines were investigated by KRAS and TP53 sequencing or SMAD4 and p53 immunohistochemistry. Xenografts using AMCPAC cell lines were established. Results: From the 81 pancreatic ductal adenocarcinomas, six (7.4% success rate) patient-derived primary cell lines were established. The six AMCPAC cell lines showed various morphologies and exhibited a wide range of doubling times. AMCPAC cell lines contained mutant KRAS in codons 12, 13, or 61 and TP53 in exon 5 as well as showed aberrant p53 (5 overexpression and 1 total loss) or DPC4 (all 6 intact) expression. AMCPAC cell lines demonstrated homology for the KRAS mutation and p53 expression compared with matched primary cancer tissues, but showed heterogeneous DPC4 expression patterns. Conclusions: The novel AMCPAC01-06 cell lines established in this study may contribute to the understanding of pancreatic ductal adenocarcinomas. [ABSTRACT FROM AUTHOR]

Purpose: Although the mutation status of KRAS is highly concordant in primary and metastatic lesions, it has not been generalized to other major pathway genes. Materials and Methods: In this study, 41 genes were evaluated and the mutational profiles were compared in 46 colorectal cancer patients with paired surgical specimens of primary and metastatic lesions: synchronous (n=27) and metachronous (n=19) lesions. A high-throughput mass spectrometry- based genotyping platform validated by orthogonal chemistry, OncoMap v.4.4, was used to evaluate the formalin-fixed, paraffin-embedded surgical specimens. The patients' demographics, tumor characteristics, and microsatellite instability status were analyzed by a retrospective chart review. Results: In this study, with OncoMap, mutations were identified in 80.4% of patients with the following frequency: KRAS (39.1%), TP53 (28.3%), APC (28.3%), PIK3CA (6.5%), BRAF (6.5%), and NRAS (4.3%). Although 19.6% (9/46) of the patients showed no gene mutations, 43.5% (20/46) and 37.0% (17/46) had mutations in one and two or more genes, respectively. The synchronous and metachronous lesions showed similar mutational profiles. Paired samples between primary and metastatic tumors differed in 7.4% (2/27) and 10.5% (2/19) for synchronous and metachronous according to OncoMap. Conclusion: These findings indicate the major pathway genes, including KRAS, TP53, APC, PIK3CA, BRAF, and NRAS, are often concordant between the primary and metastatic lesions regardless of the temporal relationship of metastasis. [ABSTRACT FROM AUTHOR]

Purpose: Cetuximab demonstrates improved efficacy outcomes in patients with metastatic colorectal cancer (mCRC) harboring wild-type KRAS exon 2. Resistance to cetuximab is mediated by activating less frequent mutations in the RAS genes beyond KRAS exon 2. We performed extended RASmutational analysis using a high -throughput genotyping platform (OncoMap) and evaluated extended RAS analysis for predicting cetuximab efficacy in patients harboring wild-type KRAS exon 2 tumors following Sanger sequencing. Materials and Methods: Extended RAS analysis was performed on 227 wild-type KRAS exon 2 mCRC patients who received cetuximab as salvage treatment using OncoMap ver. 4.0. Targeted genes included exon 2, exon 3, and exon 4, both in KRAS and NRAS, and included BRAF exon 15. We assessed efficacy by the new RAS mutation status. Results: The OncoMap detected 57 additional mutations (25.1%): 25 (11%) in KRAS exon 2 and 32 (14.1%) beyond KRAS exon 2. Survival differences were observed after dividing patients into the wild-type RAS group (n=170) and mutant RAS group (n=57) using OncoMap. Progression-free survival was 4.8 months versus 1.8 months (hazard ratio [HR], 0.44; 95% confidence interval [CI], 0.32 to 0.61), and overall survival was 11.9 months versus 8.4 months (HR, 0.65; 95% CI, 0.47 to 0.88). Conclusion: Sanger sequencing is not sufficient for selecting candidates for cetuximab treatment. High - throughput extended RAS genotyping is a feasible approach for this purpose and identifies patients who might benefit from cetuximab treatment. [ABSTRACT FROM AUTHOR]

Triple-negative breast cancer (TNBC) is a breast cancer subtype that has an aggressive phenotype, is highly metastatic, has limited treatment options and is associated with a poor prognosis. In addition, metastatic TNBC has no preferred standard chemotherapy due to resistance to anthracyclines and taxanes. The present study demonstrated that a herbal extract, SH003, reduced cell viability and induced apoptosis in TNBC without cell cytotoxicity. Cell viability was examined using trypan blue exclusion and colony formation assays, which revealed a decrease in the cell viability. Additionally, apoptosis was determined using flow cytometry and a sub-G1 assay, which revealed an increase in the proportion of cells in the sub-G1 phase. The present study investigated the anticancer effect of SH003 in the Hs578T, MDA-MB-231 and ZR-751 TNBC cell lines, and in the MCF7 and T47D non-TNBC cell lines. Western blot analysis revealed that the expression levels of poly-ADP-ribose polymerase (PARP) cleavage protein in cells treated with SH003 were increased dose-dependent manner, indicating that SH003 induced apoptosis via a caspase-dependent pathway. Pre-treatment with the caspase inhibitor Z-VAD reduced SH003-induced apoptosis was examined using trypan blue exclusion. Moreover, SH003 treatment enhanced the p73 levels in MDA-MB-231 cells but not in MCF7 cells. Transfection of p73 small interfering RNA (siRNA) in MDA-MB0231 cells revealed that the apoptotic cell death induced by SH003 was significantly impaired in comparison with scramble siRNA transfected MDA-MB-231 cells. This was examined using trypan blue exclusion and flow cytometry analysis (sub-G1). In addition, SH003 and paclitaxel exhibited synergistic anticancer effects on TNBC cells. The results indicate that SH003 exerts its anticancer effect via p73 protein induction and exhibits synergistic anticancer effects when combined with paclitaxel. [ABSTRACT FROM AUTHOR]

During the past two years, three immune checkpoint inhibitors, ipilimumab, nivolumab and pembrolizumab, have been approved and revolutionized cancer immunotherapy. Translational and clinical pharmacology of these agents have contributed in identifying patients who will receive benefit, dose effect relationship and surrogate endpoints of clinical benefit. In addition, population pharmacokinetics/pharmacodynamics have facilitated scientific clinical development, which has led to accelerated approval of these agents. This paradigm may show how early phase studies may allow identification of subgroup of patients who can benefit and subsequent approval of drugs based on smaller patient population. This may speed the access of effective treatment for patients with lifethreatening diseases. [ABSTRACT FROM AUTHOR]

Background and Study Aims: New methods for the endoscopic selective ablation of locally advanced pancreaticobiliary malignancies as a minimally invasive approach are needed. Our aim was to examine the feasibility and safety of endoscopic ultrasonography (EUS)-guided photodynamic therapy (PDT) for local tumor control in patients with locally advanced pancreaticobiliary malignancies.Patients and Methods: A chlorin e6 derivative and a flexible laser-light catheter were used to perform EUS-guided PDT in four patients with locally advanced pancreaticobiliary malignancies.Results: EUS-guided PDT was technically feasible in all four patients with locally advanced pancreaticobiliary malignancies (two in the caudate lobe of the liver, one in the far distal bile duct, and one in the tail of the pancreas). No treatment-related complications occurred. The median volume of necrosis produced by PDT was 4.0 cm(3) (range 0.7 - 11.3). Disease remained stable in all four patients during a median follow-up of 5 months (range 3 - 7).Conclusion: These preliminary data suggest that EUS-guided PDT with a second-generation photosensitizer and a flexible laser probe is feasible and safe. [ABSTRACT FROM AUTHOR]

Purpose Regorafenib, an oral multi-targeted tyrosine kinase inhibitor, is considered the new standard of care in patients with chemotherapy-refractory colorectal cancers (CRCs). However, there are no data on this drug in Korean patients. Materials and Methods We evaluated patients who received oral regorafenib 160 mg once daily during the first 3 weeks of each 4-week cycle between August 2013 and September 2013. All patients had previously progressed fluorouracil, irinotecan, and oxaliplatin with or without biologic agents such as cetuximab or bevacizumab. Results Thirty-two patients were enrolled (median age, 57 years; male:female ratio, 20:12; Eastern Cooperative Oncology Group performance status [0-1:2], 31:1; colon:rectum, 21:11). The overall response rate was 3.1% and the disease control rate was 50.0% (95% confidence interval [CI]) with one partial response and 15 patients with stable disease. The median progression-free survival was 4.2 months (95% CI, 3.1 to 5.2 months) and the median overall survival has not yet been reached. The most common adverse events of grade two or higher related to regorafenib were hand-foot skin reaction (25%), mucositis (19%), abdominal pain (9%), and liver function test (LFT) abnormalities (9%). Grade 3 or 4 toxicities included LFT abnormalities (9%), abdominal pain (9%), rash (6%), anemia (3%), leukopenia (3%), neutropenic fever (3%), and fatigue (3%). There was no treatment-related death. Conclusion Regorafenib appears to have promising activity and tolerable toxicity profiles in Korean patients with refractory CRC, consistent with the CORRECT trial findings. [ABSTRACT FROM AUTHOR]

Background We report updated progression-free survival (PFS) and overall survival (OS) data from a trial that compared capecitabine plus oxaliplatin (CapeOX) versus S-1 plus oxaliplatin (SOX) for the first-line treatment of metastatic colorectal cancer. Methods This trial was a randomized, two-armed, non-inferiority phase 3 comparison of CapeOX (capecitabine 1000 mg/m2 twice daily on days 1-14 and oxaliplatin 130 mg/m2 on day 1) versus SOX (S-1 40mg/m2 twice daily on days 1-14 and oxaliplatin 130 mg/m2 on day 1). The primary end point was to show non-inferiority of SOX relative to CapeOX in terms of PFS. Thus, a follow-up exploratory analysis of PFS and OS was performed. Results The intention to treat (ITT) population was comprised of 340 patients (SOX arm: 168 and CapeOX arm: 172). The updated median PFS was 7.1 months (95% CI 6.4-8.0) in the SOX group and 6.3 months (95% CI 4.9-6.7) in the CapeOX group (hazard ratio [HR], 0.83 [0.66- 1.04], p = .10). The median OS was 19.0 months (95% CI 15.3-23.0) in the SOX group and 18.4 months (95% CI 14.1-20.7) in the CapeOX group (HR, 0.86 [0.68-1.08], p = .19). Subgroup analyses according to principal demographic factors such as sex, age, ECOG (Eastern Cooperative Oncology Group) performance status, primary tumor location, measurability, previous adjuvant therapy, number of metastatic organs, and liver metastases showed no interaction between any of these characteristics and the treatment. Conclusions Updated survival analysis shows that SOX is similar to CapeOX, confirming the initial PFS analysis. Therefore, the SOX regimen could be an alternative first-line doublet chemotherapy [ABSTRACT FROM AUTHOR]

Background: We report updated progression-free survival (PFS) and overall survival (OS) data from a trial that compared capecitabine plus oxaliplatin (CapeOX) versus S-1 plus oxaliplatin (SOX) for the first-line treatment of metastatic colorectal cancer. Methods: This trial was a randomized, two-armed, non-inferiority phase 3 comparison of CapeOX (capecitabine 1000 mg/m2 twice daily on days 1-14 and oxaliplatin 130 mg/m2 on day 1) versus SOX (S-1 40 mg/m2 twice daily on days 1-14 and oxaliplatin 130 mg/m2 on day 1). The primary end point was to show non-inferiority of SOX relative to CapeOX in terms of PFS. Thus, a follow-up exploratory analysis of PFS and OS was performed. Results: The intention to treat (ITT) population was comprised of 340 patients (SOX arm: 168 and CapeOX arm: 172). The updated median PFS was 7.1 months (95% CI 6.4-8.0) in the SOX group and 6.3 months (95% CI 4.9-6.7) in the CapeOX group (hazard ratio [HR], 0.83 [0.66-1.04], p = .10). The median OS was 19.0 months (95% CI 15.3-23.0) in the SOX group and 18.4 months (95% CI 14.1-20.7) in the CapeOX group (HR, 0.86 [0.68-1.08], p = .19). Subgroup analyses according to principal demographic factors such as sex, age, ECOG (Eastern Cooperative Oncology Group) performance status, primary tumor location, measurability, previous adjuvant therapy, number of metastatic organs, and liver metastases showed no interaction between any of these characteristics and the treatment. Conclusions: Updated survival analysis shows that SOX is similar to CapeOX, confirming the initial PFS analysis. Therefore, the SOX regimen could be an alternative first-line doublet chemotherapy strategy for patients with metastatic colorectal cancer. [ABSTRACT FROM AUTHOR]

Three kinds of herbal medicines, commonly used in Korea, Angelicae tenuissima radix, Angelicae dahuricae radix and Scutellariae radix were studied to evaluate their effect on cytochrome P450 (CYP) activities in healthy volunteers. A total of 24 healthy male volunteers were assigned to one of three parallel herbal treatment groups, each consisting of eight volunteers. A cocktail of probe drugs for CYP enzymes was orally administered before and after multiple administrations of herbal medicines, three times a day for 13 days. Probe drugs used to measure CYP activities were caffeine (CYP1A2), losartan (CYP2C9), omeprazole (CYP2C19), dextromethorphan (CYP2D6), chlorzoxazone (CYP2E1) and midazolam (CYP3A4). The probe drugs and their metabolites were quantified in plasma or urine using HPLC or LC-MS/MS. Changes in each CYP activity was evaluated by metabolic ratio of the probe drug (concentration ratio of metabolite to parent form at reference time point) following the herbal medication period, compared to the baseline values. A. dahuricae radix significantly decreased CYP1A2 activity to 10% of baseline activity (95% CI: 0.05–0.21). S. radix also showed significant changes in CYP2C9 and CYP2E1 activities. Compared to baseline values, the metabolic activities of losartan were decreased to 71% (0.54–0.94). In addition, S. radix showed a 1.42-fold (1.03–1.97) increase in chlorzoxazone metabolic activity. However, CYP activities were not meaningfully influenced by A. tenuissima radix. Changes in certain CYP activities were observed after the administration of S. radix and A. dahuricae radix in healthy volunteers. Therefore, herbal medicines containing S. radix or A. dahuricae radix are candidates for further evaluation of clinically significant CYP-mediated herb-drug interactions in human beings. [ABSTRACT FROM AUTHOR]

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • Udenafil is a newly marketed phosphodiesterase type 5 (PDE5) inhibitor. • Udenafil is safe and well tolerated in healthy subjects, and effective as treatment for erectile dysfunction. • The effect of food on the pharmacokinetics of PDE5 inhibitors varies. WHAT THIS STUDY ADDS • This is the first study to determine the effect of food on the pharmacokinetics of udenafil. • Food generally does not affect the bioavailability of udenafil, although a low-fat diet shows a tendency to decreases the absorption rate of udenafil. AIMS Udenafil is a cyclic guanosine 3′,5′-monophosphate-specific phosphodiesterase type 5 (PDE5) inhibitor developed for the treatment of erectile dysfunction. The aim was to evaluate the effect of food on the pharmacokinetics of udenafil. METHODS An open, randomized, three-way crossover study was conducted. Fifteen healthy male volunteers received a single 200-mg oral dose of udenafil while fasting, after a low-fat meal, and after a high-fat meal separated by 7-day washout periods. Serial blood samples were taken up to 48 h after oral administration. RESULTS Under fasting conditions, udenafil was rapidly absorbed and tmax was observed typically 1.5 h after administration. The mean tmax values after a low-fat meal and a high-fat meal were 2.6 and 2.1 h, respectively. The ratios (90% confidence intervals) of the geometric means compared with the fasting condition for Cmax and AUClast were 0.79 (0.70, 0.90) and 0.96 (0.89, 1.03) in the low fat-fed condition, respectively, and 1.01 (0.89, 1.15) and 1.03 (0.96, 1.11), respectively, in the high fat-fed condition. CONCLUSIONS The tmax of udenafil was delayed under the fed conditions. However, although the Cmax was reduced by approximately 21% in the low fat-fed state, overall bioavailability was not affected when taken with food. [ABSTRACT FROM AUTHOR]

In recent years a peculiar type of chronic pancreatitis with underlying autoimmunity has been described. Lymphoplasmacytic infiltration and fibrosis on histology and elevated IgG levels or detected autoantibodies on laboratory data support the concept of autoimmune chronic pancreatitis (AIP). Pancreatic imaging reveals a rare association of diffuse enlargement of the pancreas and irregular narrowing of the main pancreatic duct, which is unique and specific to AIP. Although AIP is not a common disease, it is increasingly being recognized as knowledge of this entity builds up. Clinically it is very important to be aware of this disease because AIP can clinically disguise as pancreaticobiliary malignancies, ordinary chronic, or acute pancreatitis. Above all, AIP is a very attractive disease to clinicians in terms of its dramatic response to oral steroid therapy in contrast to ordinary chronic pancreatitis. This review discusses the clinical, laboratory, histologic, and imaging findings that are seen in patients with AIP, especially focusing on the diagnosis. [ABSTRACT FROM AUTHOR]