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Background: The transmembrane glycoprotein CD44, the major hyaluronan (HA) receptor, has been proven to regulate cell growth, survival, differentiation, and migration. It is therefore widely considered to be involved in carcinogenesis. Its role as a new therapeutic target in solid tumors is under evaluation in clinical trials. The prognostic value remains controversial. Here, we aimed to investigate the correlation between CD44 expression and the clinicopathological features and survival in metastatic colorectal cancer (mCRC) patients. Methods: Data from 65 mCRC patients of the Medical Oncology Unit, University Hospital and University of Cagliari were retrospectively collected from 2008 to 2021. Immunohistochemical analysis was performed at the Pathology Division, University Hospital of Cagliari on 3 μm thick sections obtained from paraffin blocks. The intensity of immunohistochemical staining was subclassified into four groups: score 0 if negative or weak membrane staining in less than 10% of tumor cells; score 1+ if weak membrane staining in at least 10% of tumor cells or moderate membrane staining in less than 10% of tumor cells; score 2+ if moderate membrane staining in at least 10% of tumor cells or intensive membrane staining in less than 10% of tumor cells; score 3+ if intense membrane staining in at least 10% of tumor cells. Based on this score, we distinguished patients into low CD44 expression (score 0, 1+, 2+) and high CD44 expression (score 3+). Statistical analysis was performed with MedCalc (survival distribution: Kaplan–Meier; survival comparison: log-rank test; association between categorical variables: Fisher’s exact test). Results: Patients’ median age was 66 years (range 49–85). Regarding CD44 expression, score was 0 in 18 patients, 1+ in 15 patients, 2+ in 18 patients, and 3+ in 14 patients. Median overall survival (mOS) was 28.1 months (95%CI: 21.3–101). CD44 overexpression (3+) was correlated with poor prognosis (p = 0.0011; HR = 0.2), with a mOS of 14.5 months (95%CI 11.7 to 35.9) versus 30.7 months (95%CI 27.8 to 101) in lower CD44 expression. Higher CD44 expression was associated with clinically poor prognostic features: age ≥ 70 years (p = 0.0166); inoperable disease (p = 0.0008); stage IV at diagnosis (p = 0.0241); BRAF mutated (p = 0.0111), high-grade tumor (p = 0.0084). Conclusions: CD44 markedly correlated with aggressive tumor behavior and contributed to the earlier progression of disease, thus suggesting its role as a novel prognostic marker and potential therapeutic target for mCRC patients.

Background: Information about the adherence to scientific societies guidelines in the ‘real-world’ therapeutic management of oncological patients are lacking. This multicenter, prospective survey was aimed to improve the knowledge relative to 2017-2018 recommendations of the Italian Association of Medical Oncology (AIOM). Patients and methods: Treatment-naive adult patients with pancreatic adenocarcinoma were enrolled. Group A received adjuvant therapy, group B received primary chemotherapy, and group C had metastatic disease. The results on patients accrued until 31 October 2019 with a mature follow-up were presented. Results: Since July 2017, 833 eligible patients of 923 (90%) were enrolled in 44 Italian centers. The median age was 69 years (range 36-89 years; 24% >75 years); 48% were female; 93% had Eastern Cooperative Oncology Group (ECOG) performance status (PS) score of 0 or 1; group A: 16%, group B: 30%; group C: 54%; 72% Nord, 13% Center, 15% South. In group A, guidelines adherence was 68% [95% confidence interval (CI) 59% to 76%]; 53% of patients received gemcitabine and 15% gemcitabine þ capecitabine; median CA19.9 was 29 (range 0-7300; not reported 15%); median survival was 36.4 months (95% CI 27.5-47.3 months). In group B, guidelines adherence was 96% (95% CI 92% to 98%); 55% of patients received nab-paclitaxel þ gemcitabine, 27% FOLFIRINOX, 12% gemcitabine, and 3% clinical trial; median CA19.9 was 337 (range 0-20220; not reported 9%); median survival was 18.1 months (95% CI 15.6-19.9 months). In group C, guidelines adherence was 96% (95% CI 94% to 98%); 71% of patients received nabpaclitaxel þ gemcitabine, 16% gemcitabine, 8% FOLFIRINOX, and 4% clinical trial; liver and lung metastases were reported in 76% and 23% of patients, respectively; median CA19.9 value was 760 (range 0-1374500; not reported 9%); median survival was 10.0 months (95% CI 9.1-11.1 months). Conclusions: The GARIBALDI survey shows a very high rate of adherence to guidelines and survival outcome in line with the literature. CA19.9 testing should be enhanced; nutritional and psychological counseling represent an unmet need. Enrollment to assess adherence to updated AIOM guidelines is ongoing.

BackgroundRechallenge with EGFR inhibitors represents a promising strategy for patients with RAS wild type (WT) colorectal cancer (CRC) but definitive selection criteria are lacking. Recently, the RAS WT status on circulating tumor DNA (ct-DNA) emerged as a potential watershed for this strategy. Our study explored the liquid biopsy-driven cetuximab rechallenge in a RAS and BRAF WT selected population.MethodsCRC patients with RAS and BRAF WT both on tumor tissue and on ct-DNA at baseline receiving rechallenge with cetuximab were eligible for our analysis. Ct-DNA was analyzed for RAS-BRAF mutations with pyro-sequencing and nucleotide sequencing assays. Real-time PCR and droplet digital PCR were performed to confirm the RAS-BRAF mutational status.ResultsA total of 26 patients were included in our analysis. In the global population, RR was 25.0%, median overall survival (mOS) was 5.0 months, and median progression-free survival (mPFS) was 3.5 months. Previous response to anti-EGFR was associated with improved mPFS (5.0 vs. 2.0 months, HR: 0.26, p = 0.048); anti-EGFR free interval > 14 months and anti-EGFR free interval > 16 months were associated with improved mPFS (respectively 7.0 vs. 3.0 months, HR: 0.27, p = 0.013 and not reached vs. 3.0 months, HR: 0.20, p = 0.002) and with improved mOS (respectively 13.0 vs. 5.0 months, HR: 0.27, p = 0.013 and 13.0 vs. 5.0 months, HR: 0.20, p = 0.002). Previous lines >2 were correlated with improved mPFS (4.0 vs. 1.0 month, HR: 0.05, p = 0.041) and with improved mOS (7.0 vs. 1.0 month, HR: 0.045, p = 0.034). In a multiple logistic regression model, only the anti-EGFR free interval was confirmed to be a significant predictor for mOS and mPFS.ConclusionsLiquid biopsy-driven cetuximab rechallenge was confirmed to be effective. The clinical outcome was consistent with available results from phase II studies. In addition to the molecular selection through the analysis of ct-DNA for RAS, the long anti-EGFR free interval is confirmed as a prospective selection criterion for this therapeutic option.

DNA methylation alterations are early events during tumourigenesis, affecting genes involved in the crosstalk between cells and surroundings in colorectal cancer (CRC). Among these genes, GRIA4, Glutamate Ionotropic Receptor AMPA Type Subunit 4, displays hypermethylation in the promoter region, and is an early diagnostic biomarker. It is well known that methylation can also affect alternative transcription. The purpose of this study is to evaluate the expression, at transcript and protein level, of GRIA4 main isoforms (the canonical one and a short variant) in 23 CRC and matched normal samples, of which we previously verified the methylation status. We further predicted miRNA/transcript target interactions as a possible post-transcriptional regulation using bioinformatics tools. As expected, downregulation of both variants has been observed in tumours. Interestingly, in contrast to what observed at transcriptional level, the GluR4 protein short isoform displayed higher expression than the canonical one either in normal or tumoural tissues. This may be explained by miRNA specifically targeting the canonical isoform. Our study is the first one that shows the expression of both isoforms in colon tissues. To note, the evident expression of the short isoform suggests a functional role in intestinal cell biology.

Despite continued research, pancreatic ductal adenocarcinoma (PDAC) remains one of the main causes of cancer death. Interest is growing in the role of the tumour suppressors breast cancer 1 (BRCA1) and BRCA2—typically associated with breast and ovarian cancer—in the pathogenesis of PDAC. Indeed, both germline and sporadic mutations in BRCA1/2 have been found to play a role in the development of PDAC. However, data regarding BRCA1/2-mutant PDAC are lacking. In this review, we aim to outline the specific landscape of BRCA-mutant PDAC, focusing on heritability, clinical features, differences between BRCA1 and 2 mutations and between germline and sporadic alterations, as well as established therapeutic strategies and those that are still under evaluation.

Background Biliary tract cancers (BTC) are rare but highly aggressive tumours with poor prognosis, usually detected at advanced stages. Herein, we aimed at identifying BTC-specific DNA methylation alterations. Methods Study design included statistical power and sample size estimation. A genome-wide methylation study of an explorative cohort (50 BTC and ten matched non-tumoral tissue samples) has been performed. BTC-specific altered CpG islands were validated in over 180 samples (174 BTCs and 13 non-tumoral controls). The final biomarkers, selected by a machine-learning approach, were validated in independent tissue (18 BTCs, 14 matched non-tumoral samples) and bile (24 BTCs, five non-tumoral samples) replication series, using droplet digital PCR. Results We identified and successfully validated BTC-specific DNA methylation alterations in over 200 BTC samples. The two-biomarker panel, selected by an in-house algorithm, showed an AUC > 0.97. The best-performing biomarker (chr2:176993479-176995557), associated with HOXD8, a pivotal gene in cancer-related pathways, achieved 100% sensitivity and specificity in a new series of tissue and bile samples. Conclusions We identified a novel fully efficient BTC biomarker, associated with HOXD8 gene, detectable both in tissue and bile by a standardised assay ready-to-use in clinical trials also including samples from non-invasive matrices.

752 Background: Glucose and other metabolites (lactates and glutamine) in the tumor microenvironment (TME) may alter the activity of the immune system cells. Cancer cells consume glucose and its decrease in the TME affects the function of tumour-infiltrating lymphocytes (TILs). Moreover, tumor-infiltrated immunosuppressive cells and vascular endothelial cells also deplete nutrients, in the TME, enhancing an immunosuppressive environment. On the basis of the results coming from our previous works regarding lymphocytes to monocytes ratio (LMr) and diabetes, suggesting a role for each of them as predictors of better outcomes, in this study we evaluate both of them in order to establish a possible role of them as outcomes predictive factors. Methods: Data from 228 patients (pts) were collected retrospectively from 2016 to 2021: 175 from the Medical Oncology Unit of University Hospital of Cagliari; 53 from the Medical Oncology Unit, AOU Ospedali Riuniti di Ancona. All pts had stage IV disease and received gemcitabine plus nab-paclitaxel 1st line chemotherapy. Statistical analysis was performed with the MedCalc package. We aimed to evaluate the correlation between treated DM2 and lymphocytes to monocytes ratio (LMr) ≥ 4 with outcomes. Survival distribution was assessed by Kaplan-Meier curves. Multivariate analysis was performed taking into consideration the following prognostic factors: sex, ECOG-PS, LMr, NLr, LDH, Ca19.9, and metastatic sites. Results: Median age was 68 (±9), 123/228 (54%) were male, 94/232 (40,6%) were affected by DM2 (insulin or metfomin-treated) and 138 (59,4%) pts were not affected by DM2. 52/228 (23%) pts had a LMr ≥ 4, 176/228 (77%) pts had a LMr < 4. In multivariate analysis, DM2 and LM ratio ≥ 4 were found to be independent factors associated with higher overall survival. Therefore, we divided the pts into 3 groups: co-presence DM2 and LM ≥ 4 (DM+LM+); absence of DM2 and LM ≥ 4 (DM-LM-); presence of DM2 or LM ≥ 4 (DM+LM- or DM-LM+). DM+LM+ demonstrated statistically significantly higher median OS than DM+LM-/DM-LM+ and DM-LM- (not reached versus 21 versus 9 months, respectively, p < 0.0001). Furthermore, DM+LM+ showed a statistically significant better median PFS than DM+LM-/DM-LM+ and DM-LM- (11 versus 9 versus 6 months, respectively, p = 0,0036). Conclusions: Results showed a correlation between pts with DM2/LMr ≥ 4 and better outcomes. This may suggest the presence of a link between glucose metabolism and lymphocytes activation. Antidiabetic medications could promote the inhibition of Warburg effect in tumor cells, and, consequently, provide a better glucose intake to extracellular microenvironment, and immune cells, including T lymphocytes. This process leads to a higher activity of T-cells and a better treatment response. Further studies are warranted.

Advanced hepatocellular carcinoma (HCC) is the most frequent liver cancer. Immunotherapy has been explored in this disease in order to improve survival outcomes. Nowadays, scientific research is focusing especially on immune checkpoint inhibitors, in particular anti-PD1, anti-PD-L1 and anti-CTLA4 monoclonal antibodies (mAbs), as single-agent or in combination with other immunotherapy agents, target therapies, anti-vascular endothelial growth factor (VEGF) and other agents targeting specific molecular pathways. Other immunotherapy strategies have been assessed or are under investigation in advanced HCC, namely cytokines, adoptive cell therapy, oncolytic virus, cancer vaccines. Each treatment presents specific efficacy and toxicity profiles, strictly related to their mechanism of action and to advanced HCC tumour microenvironment (TME). The aim of this review is to outline the state-of-the-art of immunotherapy in advanced HCC treatment, highlighting data on already investigated treatment strategies, safety and toxicity (including HBV/HCV-related HCC), and ongoing clinical trials focusing on new promising therapeutic weapons.

Background: In the last decade, a series of analyses failed to identify predictive biomarkers of resistance/susceptibility for anti-angiogenic drugs in metastatic colorectal cancer (mCRC). We conducted an exploratory preplanned analysis of serum pro-angiogenic factors (SErum aNgiogenesis-cenTRAL) in 72 mCRC patients enrolled in the phase II CENTRAL (ColorEctalavastiNTRiAlLdh) trial, with the aim to identify potential predictive factors for sensitivity/resistance to first line folinic acid-fluorouracil-irinotecan regimen (FOLFIRI) plus bevacizumab. Methods: First-line FOLFIRI/bevacizumab patients were prospectively assessed for the following circulating pro-angiogenic factors, evaluated with ELISA (enzyme-linked immunosorbent assay)-based technique at baseline and at every cycle: Vascular endothelial growth factor A (VEGF-A), hepatocyte growth factor (HGF), stromal derived factor-1 (SDF-1), placental derived growth factor (PlGF), fibroblast growth factor-2 (FGF-2), monocyte chemotactic protein-3 (MCP-3), interleukin-8 (IL-8). Results: Changes in circulating FGF-2 levels among different blood samples seemed to correlate with clinical outcome. Patients who experienced an increase in FGF-2 levels at the second cycle of chemotherapy compared to baseline, had a median Progression Free Survival (mPFS) of 12.85 vs. 7.57 months (Hazard Ratio&mdash, HR: 0.73, 95% Confidence Interval&mdash, CI: 0.43-1.27, p = 0.23). Similar results were seen when comparing FGF-2 concentrations between baseline and eight-week time point (mPFS 12.98 vs. 8.00 months, HR: 0.78, 95% CI: 0.46&ndash, 1.33, p = 0.35). Conclusions: Our pre-planned, prospective analysis suggests that circulating FGF-2 levels&rsquo, early increase could be used as a marker to identify patients who are more likely to gain benefit from FOLFIRI/bevacizumab first-line therapy.

Introduction: The association between pancreatic ductal adenocarcinoma (PDAC) and type 2 diabetes mellitus (DM2) has long been evaluated and the role of antidiabetic medications such as metformin has also been investigated. The objective of this study was to examine the association between insulin use and overall survival (OS) in patients with advanced PDAC and DM2. Methods: We retrospectively collected data from 164 patients, including an exploratory cohort of 96 patients from Medical Oncology Unit, University Hospital and University of Cagliari, Italy, and a validation cohort of 68 patients from Medical Oncology of Modena University Hospital. Patients had metastatic disease and received a first-line gemcitabine-based chemotherapy and, subsequently, a second-line fluoropyrimidines-based chemotherapy. We performed univariate analysis to evaluate correlation between long-term diabetes and overall survival. Then we performed multivariate analysis, adjusting for sex, metastatic sites, Eastern Cooperative Oncology Group Performance Status, Ca19.9 levels, N/L ratio, and lactate dehydrogenase levels at diagnosis, to confirm the independence of the variable. Results: In the exploratory cohort, DM2 was significantly associated with higher median OS at univariate analysis (16 vs 10 months; p = 0.004). This result was confirmed by validation cohort (11 months vs 6 months; p = 0.01). In multivariate analysis, insulin-treated patients compared with non diabetic patients showed a significantly increased survival of 4.6 months ( p = 0.03). Conclusions: Patients with insulin-treated metastatic PDAC showed better OS than non diabetic patients, as demonstrated by both cohorts. The correlation between OS and insulin-treated DM2 should be investigated further through a prospective clinical trial.

BackgroundKRAS mutations in metastatic colorectal cancer (mCRC) define a subset of tumors that have primary resistance to anti-EGFR-based therapy. Data concerning whether different KRAS mutations may also have a prognostic value are lacking. Furthermore, novel KRAS G12C inhibitors are currently in development. The aim of our analysis was to compare response rates in patients treated with first-line chemotherapy doublet + Bevacizumab among different KRAS variants. Secondary end-points were progression free survival (PFS) and overall survival (OS).MethodsPatients with KRAS mutated mCRC treated with either FOLFIRI/FOLFOX/XELOX + Bevacizumab were eligible for enrollment. Patients whose tumor harbored NRAS mutations or that coexpressed also BRAF mutations were excluded from this retrospective analysis. Patients’ individual data were collected from patients’ records. Propensity score matching (nearest method, 1:2 ratio) was used to define the two different groups of patients for comparison (KRAS G12C mutated vs other KRAS variants). Eastern Cooperative Oncology Group Performance Status (ECOG PS), sex, metastatic site of involvement, synchronous vs metachronous metastatic disease, tumor sidedness, mucinous histology, primary tumor surgery, more than two lines of treatment for metastatic disease, and radical surgery of metastases were used as matching factors. Response rate (RR) was calculated by RECIST 1.1 criteria. Both progression free-survival and overall survival were calculated by Kaplan–Meier method. Categorical variables were compared by Fisher exact test for binomial variables and by chi-square test for all other instances. The level of statistical significance p was set at 0.05 for all tests.ResultsA total of 120 patients were assessed in the final analysis. Out of the 120 patients, 15 (12%) were KRAS G12C mutated. In the whole cohort of patients, 59/120 (49%) had partial response (PR), 42/120 (35%) had stable disease (SD), and 19/120 (16%) had progressive disease (PD) as the best response. In KRAS G12C patients, 4/15 (27%) had PR, 6/15 (40%) had SD, and the remaining 5/15 (33%) had PD as the best response. In patients with other KRAS mutations, 55/105 (52%) had PR, 37/105 (35%) had SD, and the remaining 13/105 (12%) had PD as the best response. The difference in RR between the two groups of patients was statistically significant (p=0.017). On the other hand, no difference in PFS (p=0.76) and OS (p=0.56) was observed. After matching procedures, the difference in response rates between KRAS G12C mutated patients vs the matched cohort of patients with other KRAS mutations remained statistically significant (p=0.016). KRAS G12C mutations were not associated with differences in sites of metastatic involvement, sex, and ECOG PS. On the other hand, synchronous vs metachronous metastatic disease (p=0.039), age > 75 years (p=0.043), and mucinous histology (p=0.008) were more frequent in G12C mutated tumors.ConclusionsIn our cohort of patients, it was observed that KRAS G12C mutations are associated with worse response rates compared to other KRAS variants when treated with standard chemotherapy doublet + Bevacizumab. On the other hand, both PFS and OS were not significantly different. Based on these findings, we believe that new treatment options focused on KRAS G12C inhibition should be tested mainly in first-line setting and in addition to standard chemotherapy doublet + Bevacizumab for mCRC patients, as they might “fill the gap” in response rates that was seen in our study.

Background Preclinical and clinical data indicate that p53 expression might modulate the activity of the epidermal growth factor receptor (EGFR), influencing response/resistance to anti-EGFR monoclonal antibodies. However, the association between p53 status and clinical outcome has not been clarified yet. Objective In our study, we evaluated the role of p53 expression in patients with RAS/BRAF wild-type metastatic colorectal cancer (mCRC) receiving irinotecan/cetuximab in an exploratory and a validation cohort. Patients and Methods p53 expression was analysed in patients with RAS/BRAF wild-type mCRC receiving second-line or third-line irinotecan/cetuximab. Survival distribution was assessed by the Kaplan–Meier method, while the log-rank test was used for survival comparison. Results Among 120 patients with RAS/BRAF wild-type mCRC included in our analysis, 52 (59%) and 19 (59%) patients showed p53 overexpression in the exploratory and validation cohort, respectively. In the exploratory cohort, low p53 expression was correlated with better median progression-free survival (hazard ratio 0.39; p < 0.0001), median overall survival (hazard ratio: 0.23; p < 0.0001) and response rate (p < 0.0001). These results were confirmed by data of the validation cohort where we observed better median progression-free survival (hazard ratio: 0.48; p = 0.0399), median overall survival (hazard ratio: 0.26; p = 0.0027) and response rate (p =0.0007) in patients with p53 normal expression mCRC. Conclusions In our study, p53 overexpression was associated with anti-EGFR treatment resistance in patients with RAS/BRAF WT mCRC, as confirmed in a validation cohort. Larger studies are needed to validate the role of p53 and investigate EGFR cross-talk in these patients.

4153 Background: Despite the most recent therapeutic achievements, pancreatic ductal adenocarcinoma (PDAC) is characterized by poor prognosis and response to treatments. Among the most investigated prognostic biomarkers, the lymphocyte to monocyte ratio (LMr) is gaining increasing interest in literature, mostly in hematological malignancies, breast cancer, bladder cancer, non-small cell lung cancer, colorectal cancer, and resected pancreatic adenocarcinoma. In these settings, a higher LMr allows identifying a subset of patients with a better prognosis. Our study aimed to evaluate the role of the LMr as a prognostic factor in patients affected by metastatic PDAC and to find a cut-off value able to identify a subset of patients with better prognosis and possibly susceptible to other therapeutic options. Methods: Data from 228 patients were collected retrospectively from 2014 to 2021. 175 from the Department of Medical Oncology of the University Hospital of Cagliari and 53 from the Oncology Clinic - University Hospital of Ospedali Riuniti of Ancona. All patients had metastatic PDAC and blood samples were collected before starting first-line chemotherapy. The cut-off value for LMr was calculated according to the ROC curves at 6, 12, and 18 months. Kaplan-Meier curves were then obtained for the evaluation of survivals. Finally, multivariate analysis was performed, taking into consideration the following prognostic factors: sex, ECOG-PS, NL ratio, metastatic sites, Ca19.9 and LDH. Results: The median age was 68 y.o. (range 39-84 y.o.), 123 (54%) were males. Cut off value obtained for LMR, was 4. 156 (68,4%) patients had an LMr < 4 and 72 (31,6%) patients had an LMR ≥ 4. Patients with a ratio ≥ 4 showed a statistically significant difference in terms of median overall survival compared to patients with a ratio < 4 (23 months versus 11 months, p < 0.0001). First-line median progression-free survival was also different in patients with a value greater than or equal to 4 (11 months versus 6 months, p = 0.005), suggesting a better treatment response in the first group of patients. Finally, multivariate analysis showed that LMR ≥ 4 is an independent prognostic factor for OS ( p = 0.0005). Conclusions: The results of our study show that the lymphocyte to monocyte ratio could be an important prognostic factor in patients with metastatic pancreatic ductal adenocarcinoma, although the limitations of a retrospective study should be considered. Furthermore, these findings suggest the active role of the immune response in limiting disease progression, indicating a group of patients who could benefit most from a target or combined immunotherapy treatment.

e16301 Background: The association between pancreatic ductal adenocarcinoma (PDAC) and type 2 diabetes mellitus (DM2) has long been evaluated. Indeed, DM2 can be both an epiphenomenon of PDAC and a risk factor. However, the data on the influence of DM2 and concomitant drug therapy in the progression of pancreatic neoplasms are conflicting. The present study aimed to investigate the correlation between overall survival (OS) and antidiabetic drugs in patients with metastatic pancreatic ductal adenocarcinoma and DM2. Methods: Data from 232 patients were collected retrospectively from 2014 to 2021. 174 from the Department of Medical Oncology of the University Hospital of Cagliari and 58 from the Department of Medical Oncology, AOU Ospedali Riuniti of Ancona. All patients had stage IV disease and received gemcitabine plus nab-paclitaxel first-line chemotherapy. Statistical analysis was performed with the MedCalc package. We aimed to evaluate the correlation between DM2, anti-diabetic medications (ADMs) and median overall survival (mOS). Survival distribution was assessed by Kaplan-Meier curves. Finally, multivariate analysis was performed, taking into consideration the following prognostic factors: sex, ECOG-PS, LDH, Ca19.9, and metastatic sites. Results: The median age was 69 y.o. (range 40-84 y.o.), 127 (54,7%) were male. All patients received first-line treatment with gemcitabine plus nab-paclitaxel. 138 (59,4%) patients were not affected by DM2, 94/232 (40,6%) were affected by DM2. Among DM2 patients, 57 (%) were insulin-treated and 37 (%) were metformin-treated. DM2 patients showed a statistically significant higher median overall survival (26 versus 11 months, 95% CI, p = 0,0002). Furthermore, among DM2 patients insulin-treated and metformin-treated showed a mOS of 21 months and 33 months, respectively (95% CI, p = 0.0002). Finally, multivariate analysis showed that treated-DM2 is an independent prognostic factor ( p = 0.03). Conclusions: The results of our study showed a correlation between DM2 on treatment (with insulin or metformin) and higher mOSin patients with metastatic PDAC. However, the limitations due to retrospective data collection must be considered. The mechanisms underlying these findings could be explained by maintaining optimal insulin concentration and good glycemic control during treatments, or by the activity of anti-diabetic medication in neoplastic tissues. However, further studies in this setting are needed.

Background Clustered protocadherins (PCDHs) map in tandem at human chromosome 5q31 and comprise three multi-genes clusters: α-, β- and γ-PCDH. The expression of this cluster consists of a complex mechanism involving DNA hub formation through DNA-CCTC binding factor (CTCF) interaction. Methylation alterations can affect this interaction, leading to transcriptional dysregulation. In cancer, clustered PCDHs undergo a mechanism of long-range epigenetic silencing by hypermethylation. Results In this study, we detected frequent methylation alterations at CpG islands associated to these clustered PCDHs in all the solid tumours analysed (colorectal, gastric and biliary tract cancers, pilocytic astrocytoma), but not hematologic neoplasms such as chronic lymphocytic leukemia. Importantly, several altered CpG islands were associated with CTCF binding sites. Interestingly, our analysis revealed a hypomethylation event in pilocytic astrocytoma, suggesting that in neuronal tissue, where PCDHs are highly expressed, these genes become hypomethylated in this type of cancer. On the other hand, in tissues where PCDHs are lowly expressed, these CpG islands are targeted by DNA methylation. In fact, PCDH-associated CpG islands resulted hypermethylated in gastrointestinal tumours. Conclusions Our study highlighted a strong alteration of the clustered PCDHs methylation pattern in the analysed solid cancers and suggested these methylation aberrations in the CpG islands associated with PCDH genes as powerful diagnostic biomarkers. Electronic supplementary material The online version of this article (10.1186/s13148-019-0695-0) contains supplementary material, which is available to authorized users.

Free triiodothyronine (FT3)/free thyroxine (FT4) ratio is an index estimating the peripheral activity of thyroid hormones. In a previous experience, we identified a prognostic role for FT3/FT4 ratio in chemorefractory patients treated with regorafenib. Therefore, we planned this post hoc analysis of the phase III CORRECT trial of regorafenib versus placebo.Seven hundred fifty-eight out of 760 randomised patients (503 in the regorafenib and 255 in the placebo arm) were evaluable for the present analyses, based on availability of FT3 and FT4 baseline values. Co-primary objectives were to explore the predictive role of FT3/FT4 ratio in patients treated with regorafenib compared with placebo and to validate the prognostic value of FT3/FT4 ratio in the CORRECT trial.For patients randomised to regorafenib, median overall survival (OS) was 4.0, 7.5 and 9.8 months in low, intermediate and high FT3/FT4 ratio subgroups, respectively. Hazard ratio (HR) for OS was 0.40 (p 0.0001) when comparing intermediate versus low and 0.32 (p 0.0001) when comparing high versus low FT3/FT4 ratio. In the placebo arm, median OS was 3.3, 5.6 and 7.7 months, in the three subgroups. HR for OS was 0.47 (p 0.0001) when comparing intermediate versus low and 0.33 (p 0.0001) when comparing high versus low. FT3/FT4 ratio retained its association with OS in the multivariate model in both arms.While rejecting the predictive effect of baseline FT3/FT4 ratio, present data strengthen the prognostic role of the ratio, pave the way for direct clinical application, underline the need for a better biological understanding and suggest possible therapeutic implications for thyroid hormones.

182 Background: Only few data on microsatellite instability in rectal cancer are available in literature, and dMMR role in pre-operative chemoradiotherapy response is under debate. The aim of our study was to evaluate the frequency and therapeutic implications of dMMR status in patients (pts) with locally advanced rectal cancer belonging to our Center. Methods: Data were retrospectively collected from 231 patients belonging to the Medical Oncology Unit of the University Hospital of Cagliari from 2011 to 2021. All patients were affected by locally advanced rectal adenocarcinoma (cT3-4 +/- N1-2). All patients included in the study underwent neoadjuvant chemoradiotherapy treatment with capecitabine and RT long course (total dose of Gy 50.4) and subsequently underwent total mesorectal excision (TME) followed by adjuvant chemotherapy. Mismatch repair (MMR) expression was evaluated through immunohistochemistry on surgical samples. Results: Of the 231 patients, 213 were suitable for final analyzes. Patients median age was 68 years (range 34-89). 145/201 were male and 68 were female. 66 (31%) had stage II disease and 147 (69%) had stage III disease. Considering MMR, 205/213 (96%) patients had proficient mismatch repair (pMMR), while 8/213 (4%) had dMMR. In dMMR patients defective proteins were: MSH2 in 4 patients, MLH1 and PMS2 combined in 2 patients and MSH6 in 2 patient. dMMR patients showed, unlike pMMR patients, poor or no response to chemoradiotherapy. Responses were assessed through TRG evaluation (Ryan and Dworak scoring systems) on the primary tumour. 5 patients presented a TRG-3 and 3 patients showed a TRG-4, according to Ryan score. All of them had a grade 1 regression, according to Dworak. Conclusions: The results of our study, albeit with limitations related to the retrospective nature and the limited number of dMMR cases, might indicate a correlation between microsatellite instability and little or no response to preoperative chemo-radiotherapy. It would be useful to analyze the data prospectively and further evaluate MMR as a predictor of response to combined chemo-radiotherapy.[Table: see text]

BRAF mutant colorectal cancer (BRAF MT CRC) is a unique category of colorectal tumour with peculiar molecular, pathological and clinical features and poor prognosis; despite recent research, BRAF mutation predictive value and standard treatment of BRAF MT CRC still have to be defined. In this review, we focused on this challenging topic. Areas covered: The potential use of BRAF mutational status among recent additional prognostic and predictive indicators and current treatment strategy in use in these patients is discussed. Moreover, implications and characteristics of new BRAF mutations other than BRAFV600E are analyzed. An in-deep outlook on the immediate future for clinical and translational research in this subgroup of patients is also presented, such as combination therapy with agents targeting the RAS/RAF/MEK/ERK pathway and standard chemotherapy in order to overcome resistance. We performed a research on Pubmed typing 'BRAF mutation', 'colorectal cancer', 'predictive and prognostic value', 'targeted therapy', 'BRAF inhibition'. Expert commentary: BRAFV600E mutation represents a strong, independent negative prognostic factor in II-III stage MSS CRC and mCRC. The best treatment still has to be identified; currently, in good performance status patients, an intensive-chemotherapy-combination remains the standard of care. Further investigations are warranted to explore new horizons to change BRAF MT mCRC outcomes.

Pancreatic ductal adenocarcinoma (PDAC) is associated with poor survival. Of all newly diagnosed patients, only about 20% can benefit from a potentially curative surgical resection, the remaining 80% presenting with unresectable locally advanced (LAPC) or metastatic (MPC) disease. Currently, there are limited therapeutic options for LAPC and MPC patients. Furthermore, despite intensive research efforts to better understand the molecular bases of PDAC and the biological relevance of its tumor microenvironment, treatments still largely consist of classical cytotoxic chemotherapy agents. Several studies of genetic and epigenetic sequencing have demonstrated the existence of 4 molecular PDAC subtypes, with heterogeneous genetic characteristics and different biological behaviour: squamous, pancreatic progenitor, immunogenic and aberrantly differentiated endocrine exocrine (ADEX). These distinct subtypes derive from alterations at multiple levels. Apart from the DNA repair pathway, however, none of these has so far been validated as a clinically relevant therapeutic target. Also, PDAC is unique from an immunological perspective and many studies have recently tried to elucidate the role of intratumoral effector T-cells, RAS oncogene, immunosuppressive leukocytes and desmoplastic reaction in maintaining the immunological homeostasis of this disease. However, there still remains much to be learned about the mechanisms whereby the pancreatic immune microenvironment promotes immune escape of cancer cells. Furthermore, while therapies targeting the stroma as well as immunotherapies hold promise for the future, these are not yet standard of care. This review aims to outline the state-of-the-art of LAPC and MPC treatment, highlighting data on the target therapies failure and current ongoing clinical trials on new promising therapeutic strategies.

Background Despite the well-known negative prognostic value of the V600EBRAF mutation in patients with metastatic colorectal cancer (mCRC), its outcome is quite heterogeneous, and the basis for this prognostic heterogeneity should be better defined. Methods Two large retrospective series of V600EBRAF-mutated mCRC from 22 institutions served as an exploratory and validation set to develop a prognostic score. The model was internally and externally validated. Results A total of 395 V600EBRAF-mutated mCRCs were included in the exploratory set. Performance status, CA19.9, lactate dehydrogenase, neutrophil/lymphocyte ratio, grading and liver, lung and nodal involvement emerged as independent prognostic factors for overall survival (OS). Two different scoring systems were built: a ‘complete’ score (0–16) including all significant covariates and a ‘simplified’ score (0–9), based only on clinicopathological covariates, and excluding laboratory values. Adopting the complete score, proportions of patients with a low (0–4), intermediate (5–8) and high (9–16) score were 44.7%, 42.6% and 12.6%, respectively. The median OS was 29.6, 15.5 (hazard ratio [HR] for intermediate vs low risk: 2.16, 95% confidence interval [CI]: 1.44–3.22, p Conclusions These scoring systems are based on easy-to-collect data and defined specific subgroups with relevant differences in their life expectancy. These tools could be useful in clinical practice, would allow better stratification of patients in clinical trials and may be adopted for proper adjustments in exploratory translational analyses.

3577 Background: The rechallenge with EGFR inhibitors represents an emerging strategy for anti-EGFR pre-treated patients with RAS wild type colorectal cancer (CRC). Unfortunately definitive selection criteria for anti-EGFR rechallenge in this setting are lacking. Very recently RAS wild type status on circulating tumor DNA (ct-DNA) at the time of rechallenge along with already known clinical criteria emerged as a potential watershed for this strategy. In the present study we explored liquid biopsy-driven anti-EGFR rechallenge strategy in the clinical practice for patients with metastatic colorectal cancer. Methods: Ct-DNA from RAS and BRAF wild type metastatic CRC patients previously treated with an anti-EGFR containing therapy was analyzed for RAS/BRAF mutations with the aim to evaluate the rechallenge strategy with anti-EGFR. The ct-DNA was analyzed for RAS-BRAF mutations using pyro-sequencing (PyroMark Q24 MDx Workstation) and nucleotide sequencing (Genetic Analyzer ABI3130) assays. Real-time PCR (Idylla) and droplet digital PCR (QX200 System) were performed to confirm the RAS-BRAF mutation status. Several clinical variables including previous response to anti EGFR containing therapy, tumor sidedness and anti-EGFR free interval were evaluated in relation to outcome. Tumor response evaluation was performed according to RECIST 1.1. Differences between categorical variables were evaluated using the Fisher’s exact test. Survival probability over time was estimated by the Kaplan–Meier method. Significant differences in the probability of survival between the strata were evaluated by log-rank test. Results: Twenty patients were included in the study. All patients were tested for RAS-BRAF mutations in ct-DNA. Fourteen patients (70%) showed a RAS-BRAF WT molecular profile, six patients (30%) showed a KRAS mutation. All the patients with ct-DNA RAS-BRAF WT profile underwent rechallenge with anti-EGFR. In details 11 patients (78.6%) underwent irinotecan+ cetuximab treatment, whereas 3 patients (21.4%) underwent panitumumab monotherapy. As for the outcome results to the rechallenge strategy, the median OS was 7 months (95% CI 5.0 to 13.0), the median PFS was 3 months (95% CI 2.0 to 6.0), the ORR was 27.3% with a DCR of 54.5%. Among the clinical variables evaluated as putative predictive/prognostic factors, previous response to anti-EGFR treatment was related to a not statistically significant improved OS (12 months vs 5 months HR:0.19 p: 0.06) and to a statistically significant improved ORR (75% vs 0% p:0.03). Conclusions: The rechallenge strategy with anti-EGFR confirmed to be feasible in clinical practice. The clinical outcome resulted consistent with the literature data. In addition to the molecular selection through the analysis of ct-DNA for RAS, previous response to anti EGFR treatment is confirmed as a prospective selection criteria for this therapeutic option.

e15503 Background: Data on anti-angiogenic second line treatment in RAS wild type (wt) metastatic colorectal cancer (mCRC) patients (pts) progressing after first-line anti-EGFR drug are lacking and no validated biomarkers are available. We present the pre-planned interim analysis of the DISTINCTIVE trial (NCT04252456), a biologically enriched, prospectively stratified phase 2 study assessing the aflibercept use in this setting. Methods: RAS wt mCRC pts progressing after first line oxaliplatin-based + anti-EGFR therapy and candidates for second-line FOLFIRI/aflibercept are eligible for the DISTINCTIVE trial. Pts are prospectively allocated to a favorable (F) or unfavorable (U) prognostic group, according to Elisa-assessed baseline (BL) VEGFR2 plasma levels (PL). Other circulating angiogenic factors are evaluated at BL, first tumor assessment (TA1) and disease progression (PD). Primary endpoint is overall survival (OS) according to VEGFR2 levels. Secondary endpoints are OS, progression free survival (PFS), response rate, safety and angiogenic factors levels. Statistical analysis is performed with MedCalc (survival distribution: Kaplan-Meier; survival comparison: log-rank test; multivariate analysis: logistic regression). Sample size: 151 pts (one-sided test, α: 0.1, β: 0.2). Results: From 04/2018 to 06/2020, 73 pts were enrolled. Complete data from 44 pts were available for interim analysis. 33 pts (75%) achieved DCR (26 pts/59% SD, 7 pts/16% PR). Globally, median OS was 11.9 months (m) (95%CI 10 – 14.2). 24 (54.5%) pts were prospectively assigned to F group (VEGFR2 PL > 4 ng/ml) and 20 (45.5%) to U group (VEGFR2 PL ≤4 ng/ml). OS in F group was 13.1 m (95%CI 9.6 – 14.2) vs 11.9 m (95%CI 6.8 – 11.9) in U group (HR 0.76 p = 0.6218). PFS was 9.8 m [95%CI 5.7 – 24.2] in F group vs 4.2 m [95%CI 2.5 – 14.2] in U group (HR 0.41 p = 0.0105). We also found preliminary correlation with PD as shown in table. Conclusions: Interim analysis showed high activity of FOLFIRI/aflibercept in RAS WT anti-EGFR pretreated mCRC pts. VEGFR2 showed promising ability to predict aflibercept efficacy. Our data on circulating angiogenic biomarkers are likely to further compose the landscape of anti-angiogenic activity in mCRC pts. Clinical trial information: NCT04252456. [Table: see text]

Background:The data from randomised trials suggested that primary tumour sidedness could represent a prognostic and predictive factor in colorectal cancer (CRC) patients, particularly during treatment with anti-epidermal growth factor receptor (EGFR) therapy. However, an in-deep molecular selection might overcome the predictive role of primary tumour location in this setting.Methods:We conducted a retrospective analysis in which tumour samples from RAS/BRAF wild-type (WT) metastatic CRC patients treated with second-third-line irinotecan/cetuximab were analysed for EGFR gene copy number (GCN) and promoter methylation. Study objective was to evaluate the correlation of tumour sidedness, EGFR promoter methylation and EGFR GCN with clinical outcome. Median follow-up duration was 14.3 months.Results:Eighty-eight patients were included in the study, 27.3% had right-sided CRC, 72.7% had left-sided CRC; 36.4% had EGFR GCN

BACKGROUND: Metastatic CRC (mCRC) is a molecular heterogeneous disease. The aim of this review is to give an overview of molecular-driven treatment of mCRC patients. METHODS: A review of clinical trials, retrospective studies and case reports was performed regarding molecular biomarkers with therapeutic implications. RESULTS: RAS wild-type status was confirmed as being crucial for anti-epidermal growth factor receptor (EGFR) monoclonal antibodies and for rechallenge strategy. Antiangiogenic therapies improve survival in first- and second-line settings, irrespective of RAS status, while tyrosine kinase inhibitors (TKIs) remain promising in refractory mCRC. Promising results emerged from anti-HER2 drugs trials in HER2-positive mCRC. Target inhibitors were successful for BRAFV600E mutant mCRC patients, while immunotherapy was successful for microsatellite instability-high/defective mismatch repair (MSI-H/dMMR) or DNA polymerase epsilon catalytic subunit (POLE-1) mutant patients. Data are still lacking on NTRK, RET, MGMT, and TGF-β, which require further research. CONCLUSION: Several molecular biomarkers have been identified for the tailored treatment of mCRC patients and multiple efforts are currently ongoing to increase the therapeutic options. In the era of precision medicine, molecular-biology-driven treatment is the key to impro patient selection and patient outcomes. Further research and large phase III trials are required to ameliorate the therapeutic management of these patients. ispartof: CANCERS vol:12 issue:5 ispartof: location:Switzerland status: published

e17540 Background: The Neutrophil-to-Lymphocytes ratio (NLR) represents a potential prognostic and predictive marker in a different tumor types. The purpose of our study was to investigate the prognostic value of the pretreatment inflammatory marker NLR in patients with head and neck squamous cell carcinoma (HNSCC). Methods: Pretreatment NLR were retrospectively investigated for correlation with overall survival (OS). Kaplan-Meier statistic and long rang test were used. Univariate analysis for categorical and descriptive variables were performed. Results: Thirty-nine patients, from local to advanced stage disease, were included in our analysis. At a median follow up of 9.44 months (2.04 – 30.3), of the total patients 30.7% died and 41.9% had progression of disease. The median PFS was 4.6 months (2.9 – 27.2) and the median OS (mOS) was 18.9 months. Following ROC curve analysis the optimum cut-off value of NLR was 3.93 (p = 0.017). Patient with NLR > 3.92 had a mOS of 11.9 months, whereas the mOS for NLR ≤ 3.92 was 30.3 months (Log-rank p = 0.189). The 1 year Kaplan-Meier estimates of OS for NLR ≤ 3.92 vs. >3.92 was 72% vs. 45% respectively (Log-rank p = 0.243). According to COX univariate analysis, the risk of death increases of 7.7% each unitary rise of NLR mean value (p = 0.3407). Conclusions: In our limited case series NLR was not significantly associated with clinical outcome. Therefore, multicenter studied are needed to determine an optimal NLR cutoff value. [Table: see text]

e15001 Background: Radical cystectomy (RC) with bilateral pelvic lymph node dissection and urinary diversion is considered the mainstay of treatment for muscle-invasive bladder cancer. The primary ...