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Reactive oxygen species activate EGFR/RAS/MAPK signaling either through the inactivation of phosphatases or by direct oxidation of kinases. We hypothesized that functional single-nucleotide polymorphisms (SNPs) in antioxidant genes link to the efficacy of cetuximab in patients with metastatic colorectal cancer (mCRC).We analyzed genomic and clinical data from FIRE-3, a phase III trial comparing cetuximab and bevacizumab along with FOLFIRI in untreated mCRC patients. Genomic DNA extracted from blood samples was genotyped. Thirteen functional SNPs in antioxidant genes were tested for associations with clinical outcomes.In total, 236 patients were included (FOLFIRI/cetuximab arm, n = 129; FOLFIRI/bevacizumab arm, n = 107). In univariate analysis, two SNPs (TXN2 rs4821494 and GPX4 rs4807542) were significantly associated with overall survival (OS) in the FOLFIRI/cetuximab arm. Multivariate analysis confirmed the significant association of TXN2 rs4821494 (T/T vs. any G allele, hazard ratio = 2.47, 95% confidence interval = 1.06-5.72, P = .03). In the FOLFIRI/bevacizumab arm, no SNPs were significantly associated with clinical outcomes. Treatment-by-SNP interaction test confirmed the predictive value of TXN2 rs4821494 (OS: P = .03).TXN2 rs4821494 involved in the antioxidant system may predict the efficacy of cetuximab-based first-line chemotherapy in mCRC, warranting further validation studies.

Cancer stem cells (CSCs) are primarily maintained by a network of pluripotency transcription factors (PTFs). Given a close relationship of CSC regulation with epidermal growth factor receptor and vascular endothelial growth factor signalling, we investigated whether single-nucleotide polymorphisms (SNPs) in PTF genes are related to the efficacy of cetuximab and/or bevacizumab in patients with metastatic colorectal cancer (mCRC).Genomic and clinical data from three independent clinical trial cohorts were tested: cetuximab cohort (FOLFIRI/cetuximab arm in FIRE-3, n = 129), bevacizumab cohort 1 (FOLFIRI/bevacizumab arm in FIRE-3, n = 107) and bevacizumab cohort 2 (FOLFIRI/bevacizumab arm in TRIBE, n = 215). Genomic DNA extracted from blood samples was genotyped, and ten SNPs were tested for association with clinical outcomes.In the cetuximab cohort, four SNPs were significantly associated with progression-free survival in univariate analysis: NANOG rs11055767 (any A allele vs C/C, hazard ratio [HR] = 0.62, 95% confidence interval [CI] = 0.42-0.94, p = 0.02), NANOG rs10744044 (any A allele vs G/G, HR = 0.59, 95% CI = 0.39-0.90, p = 0.01), NANOGP8 rs2168958 (any C allele vs A/A, HR = 2.12, 95% CI = 1.36-3.29, p 0.001) and NANOGP8 rs2279066 (any C allele vs T/T, HR = 1.80, 95% CI = 1.06-1.68, p = 0.03). Multivariate analysis confirmed the significant associations for NANOGP8 rs2168958 and NANOGP8 rs2279066. In either bevacizumab cohort, no significant associations were observed in univariate analysis.Germ line polymorphisms in the PTF genes could be predictive markers for cetuximab in mCRC.

Background ARID1A is a key subunit of the SWItch/Sucrose Non-Fermentable (SWI/SNF) complex which regulates dynamic repositioning of nucleosomes to repair DNA damage. Only small pilot studies have evaluated the role of ARID1A mutation in colorectal cancer (CRC). The aim of the present study was to explore the potential impact of ARID1A mutation on clinicopathological and molecular characteristics in CRC. Methods We used integrated data sets of 7978 CRC cases (one data set from a clinical laboratory improvement amendments [CLIA]-certified laboratory and three independent published data sets). The associations of ARID1A mutation with molecular characteristics including immune profile (the status of microsatellite instability [MSI], tumour mutational burden [TMB], programmed death ligand 1 [PD-L1] and estimated infiltrating immune cells), clinicopathological features and related pathways were analysed using next-generation sequencing, RNA sequencing and immunohistochemistry. Results ARID1A mutant samples had more genomically unstable tumour features (MSI-high and TMB-high) and exhibited more characteristics of a T-cell–inflamed microenvironment (PD-L1 expression and high estimated infiltrating cytotoxic T lymphocytes [CTLs]) than ARID1A wild-type samples in the discovery and validation cohorts. Even ARID1A mutant samples without MSI-high status were TMB-high, had high levels of PD-L1 expression and high estimated infiltrating CTLs. ARID1A mutations were more common with right-sided primary and earlier stage tumours. ARID1A mutant tumours mainly had co-occurring gene mutations related to chromatin modifying, DNA repair, WNT signalling and epidermal growth factor receptor inhibitor resistance pathways, and ARID1A mutations strongly regulated DNA repair pathways. Key genes for chemotherapy/radiotherapy sensitivity were suppressed in ARID1A mutant samples. Conclusions Our findings may provide novel insights to develop individualised approaches for treatment of CRC based on ARID1A mutation status.

The activation of stimulator of interferon genes (STING) was reported to enhance cetuximab-mediated natural killer cell activation and dendritic cell maturation. Polymorphisms in genes in the cyclic GMP-AMP synthase (cGAS)-STING pathway may affect innate immune response. Therefore, we hypothesised that genetic variants in the cGAS-STING pathway may predict the efficacy of cetuximab-based treatment in patients with metastatic colorectal cancer.Genomic DNA from blood samples of patients enrolled in FIRE-3 (cetuximab arm, n = 129; bevacizumab arm, n = 107) and TRIBE (bevacizumab arm, n = 215) was genotyped using the OncoArray-500K bead chip panel. Seven selected single nucleotide polymorphisms in 3 genes (cGAS, STING and interferon B1 (IFNB1)) were analysed for the association with overall survival and progression-free survival.In the cetuximab cohort, patients with STING rs1131769 any T allele showed significantly shorter overall survival (36.3 versus 56.1 months) than carriers of C/C in both univariate [hazard ratio (HR) = 2.08; 95% confidence interval (CI): 1.06-4.07; P = 0.03] and multivariate (HR = 2.98; 95% CI: 1.35-6.6; P = 0.0085) analyses; patients carrying IFNB1 rs1051922 G/A and A/A genotype showed a significantly shorter progression-free survival than carriers of G/G allele in both univariate (G/A versus G/G, 10.2 versus 14.1 months, HR = 1.84; 95% CI 1.23-2.76; A/A versus G/G, 10.7 versus 14.1 months, HR = 2.19; 95% CI 0.97-4.96; P = 0.0077) and multivariate analyses (G/A versus G/G, HR = 2; 95% CI 1.22-3.3; A/A versus G/G, HR = 2.19, 95% CI 0.92-5.26, P = 0.02). These associations were not observed in the bevacizumab arm of FIRE-3 or TRIBE.These results suggest for the first time that germline polymorphisms in STING and IFNB1 genes may predict the outcomes of cetuximab-based treatment in patients with metastatic colorectal cancer.

Background Adenosine has an immunosuppressive and angiogenic modulation of the tumor microenvironment. The present study explored the efficacy of single nucleotide polymorphisms (SNPs) in adenosine-related molecules for patients with metastatic colorectal cancer treated with bevacizumab-based chemotherapy. Patients and Methods We analyzed genomic DNA extracted from 451 samples from 3 independent cohorts: a discovery cohort of 107 patients treated with FOLFIRI (5-fluorouracil, leucovorin, oxaliplatin, irinotecan) plus bevacizumab in FIRE-3 ( ClinicalTrials.gov identifier, NCT00433927); a validation cohort of 215 patients with FOLFIRI plus bevacizumab in TRIBE ( ClinicalTrials.gov identifier, NCT00719797); and a control cohort of 129 patients treated with FOLFIRI plus cetuximab in FIRE-3. The relationship between the selected SNPs and clinical outcomes was analyzed. Results In the discovery cohort, patients with any C allele in CD39 rs11188513 had significantly shorter median progression-free survival compared with those with the T/T variant (11.3 vs. 13.1 months; hazard ratio [HR], 1.70; 95% confidence interval [CI], 1.04-2.77; P = .022) on univariate analysis. Also, their overall survival (OS) was shorter (27.4 vs. 49.9 months; HR, 2.10; 95% CI, 1.07-4.10; P = .031) on univariate and multivariable analyses. The significant association between CD39 rs11188513 and OS was confirmed in the validation cohort (25.8 vs. 31.6 months; HR, 1.53; 95% CI, 1.09-2.15; P = .013). CD73 rs2229523 and A2BR rs2015353 in the discovery cohort and CD39 rs2226163 in the validation cohort showed significant correlations with OS on univariate and multivariable analyses. None of SNPs were significant in the cetuximab control cohort. Conclusion Selected SNPs in the adenosine pathway could affect the clinical outcomes of patients with metastatic colorectal cancer treated with FOLFIRI plus bevacizumab.

Improved clinical selection and identification of new molecules and innovative strategies have widened treatment options and increased overall survival in metastatic colorectal cancer patients in recent years. Biomarker-driven therapies represent an emerging issue in this field and new targeted treatments are under investigation and probably will be soon adopted into daily clinical practice. In the present review, the role RAS, BRAF mutations, Her2 amplification, microsatellite instability, and CpG island methylator phenotype are discussed according to their possible roles as prognostic, predictive markers, as well as possible biomarker-driven treatment options.

Heme sensor Nuclear Receptor Subfamily 1 Group D Member 1 (NR1D1/REVERBA) and its target gene Aryl Hydrocarbon Receptor Nuclear Translocator-Like (ARNTL/BMAL1) regulate circadian rhythm and angiogenesis. Given their involvement in the interplay between clock disruptions (e.g. by mutations or sleep deprival), cancer risk and vascular biology, we hypothesized that these transcription factors contribute to resistance against anti-angiogenic therapy with vascular endothelial growth factor (VEGFA) neutralizing antibody (bevacizumab, abbrev. Beva) in colorectal cancer (CRC). REVERBA bound to a predicted -672 bp Retinoic Acid Receptor-Related Orphan Receptor Alpha (RORA)-responsive element (RORE) adjacent to a BMAL1 DNA-binding motif (E-box) in the proximal promoter of the human VEGFA gene. REVERBA, indirectly and together with BMAL1, increased VEGFA mRNA and protein expression. Conversely, REVERBA siRNA and REVERBA-antagonist hemin decreased VEGFA synthesis. Beva treatment inhibited CRC growth in a C57BL/6J Apc min/+ genetically modified mouse model (GEMM) and BALB/c nu/nu mouse HCT116 xenografts, without attenuating BMAL1 levels or microvessel density (MVD). In CRC patient tumors (n=74), high BMAL1 protein expression was associated with clinical non-response to combination chemotherapy with Beva (*p=0.0061) and reduced progression-free survival (PFS) [*p=0.0223, Hazard Ratio (HR)=1.69]. In addition, single nucleotide polymorphisms (SNPs) in the BMAL1 (ARNTL) gene correlated with shorter overall survival (OS) [rs11022780, *p=0.014, HR=1.61] and PFS (rs7396943, rs7938307, rs2279287) in patients undergoing combination chemotherapy with Beva. Thus, BMAL1 is associated with Beva resistance in CRC. Since the REVERBA-BMAL1-VEGFA axis can be pharmacologically targeted, interference with this signaling pathway could circumvent resistance to anti-angiogenic therapy in CRC. Funding Statement: This study was supported by grants to EB from the Deutsche Krebshilfe (#108287 and #111086). FE received a fellowship from the “Studienstiftung des deutschen Volkes”. JB was supported by the Translational Physician Scientist (TraPS) Program of the Medical Faculty Mannheim of the Heidelberg University. WW was awarded a fellowship from the Chinese Scholarship Council (#201408080116). ME was supported by the State of Baden-Wurttemberg for “Center of Geriatric Biology and Oncology (ZOBEL) – Perspektivforderung” and “Biology of Frailty - Sonderlinie Medizin”. ATB and ME received funds from the European Commission Seventh Framework Programme (Contract No. 278981 [ANGIOPREDICT]) and are supported by the European Commission Horizon 2020 Programme (Contract No. 754923 [COLOSSUS]). ATB is further supported by Science Foundation Ireland under grant 13/CDA/2183 ”Coloforetell”. HJL was partly funded by the National Cancer Institute (grant number P30CA014089), the Gloria Borges WunderGlo Foundation -The Wunder Project, the Dhont Family Foundation, the San Pedro Peninsula Cancer Guild, the Daniel Butler Research Fund, and the Call to Cure Research Fund Declaration of Interests: The authors declare no conflicts of interest. The reagent mBeva was obtained on the basis of a material transfer agreement (MTA#10082012) from Roche Diagnostics GmbH (Penzberg, Germany). HJL has received clinical trial financial support from Merck Serono and Roche and honoraria for advisory board membership and lectures from Bayer, Boehringer Ingelheim, Genentech, Merck Serono and Roche Ethics Approval Statement: Xenograft studies conformed to the 2010/63/EU guidelines and were approved by the Dept. of Health and Children, Dublin, Ireland (B100/3654) and University College Dublin Animal Research Ethics Committee (P12-27). Therapy studies were conducted in accordance with ethical guidelines (Declaration of Helsinki) and approved by the local ethics committees for each participating site. All patients provided written informed consent for the analysis of molecular correlates.

Introduction Poly-(ADP)-ribose polymerase (PARP) inhibitors are successfully used for treatment of BRCA-mutated (mut) breast cancers and are under extensive evaluation for BRCA- and PALB2-mutated pancreatic ductal adenocarcinoma (PDAC). However, the optimal treatment regimen for BRCA/PALB2-mutated PDCA has yet to be established. Moreover, limited data are available on the association of BRCA/PALB2 gene alterations with other comutations and immunological biomarkers.Material and methods Tumour samples of 2818 patients with PDAC were analysed for BRCA1/2 PALB2 mutations and other genes by next-generation sequencing (NGS) (MiSeq on 47 genes, NextSeq on 592 genes). TMB was calculated based on somatic non-synonymous missense mutations. MSI-H/dMMR was evaluated by NGS, and PD-L1 expression was determined using immunohistochemistry.Results In 4.2% (n=124) of all PDAC samples BRCA mutations have been detected. BRCA2 mutations were more commonly observed than BRCA1 mutations (3.1%(n=89) vs 1.1% [n=35], p1.0% (BRCA: 21.8% vs wt 11.2%, p

Introduction Prognosis of biliary tract cancers (BTC) remains dismal and novel treatment strategies are needed to improve survival. BRCA mutations are known to occur in BTC but their frequency and the molecular landscape in which they are observed in distinct sites of BTC remain unknown.Material and methods Tumour samples from 1292 patients with BTC, comprising intrahepatic cholangiocarcinoma (IHC, n=746), extrahepatic cholangiocarcinoma (EHC, n=189) and gallbladder cancer (GBC, n=353), were analysed using next-generation sequencing (NGS). Tumour mutational burden (TMB) was calculated based on somatic non-synonymous missense mutations. Determination of tumour mismatch repair (MMR) or microsatellite instability (MSI) status was done by fragment analysis, immunohistochemistry and the evaluation of known microsatellite loci by NGS. Programmed death ligand 1 expression was analysed using immunohistochemistry.Results Overall, BRCA mutations were detected in 3.6% (n=46) of samples (BRCA1: 0.6%, BRCA2: 3%) with no significant difference in frequency observed based on tumour site. In GBC and IHC, BRCA2 mutations (4.0% and 2.7%) were more frequent than BRCA1 (0.3% and 0.4%, p

Background Werner syndrome gene (WRN) encodes a DNA helicase with an exonuclease activity that contributes to DNA repair. In cancer, WRN mutations lead to genomic instability. It is known that WRN is necessary to sustain in-vivo growth of cancers cells with microsatellite instability (MSI), including CRC. WRN is a very promising new target especially in cancers with MSI. There is still a lack of knowledge about the frequency of WRN alterations and their association with immunological and molecular phenotypes. Methods Tumour samples from 6854 CRC patients were analyzed using NGS (NextSEQ on 592 genes), in-situ hybridization and immunohistochemistry (Caris Life Sciences, Phoenix, AZ, USA). Tumour mutational burden (TMB) was calculated based on somatic non-synonymous missense mutations, and MSI was evaluated by NGS of known MSI loci. Results WRN mutations (WRN-mut) were observed in 80 of 6854 samples (1.2%). A higher prevalence of WRN-mut was detected in right- compared to left-sided CRC (2.4% vs 0.7%, p Conclusions This is the largest profiling study to investigate the molecular and immunological landscape of WRN-mut CRCs. We show the high prevalence of MSI in WRN-mut tumours and their association with higher TMB and PD-L1 expression. Furthermore, it revealed that WRN-mut CRC is characterized by a distinct genetic profile. Our data might serve to tailor treatment in WRN-mut CRC. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.

Background One-carbon metabolism (1CM) comprises the folate and the methionine cycles and is involved in nucleotide synthesis and methylation. 1CM is known to be crucial in CRC development and progression. However, the impact of its genetic variants on prognosis in mCRC patients has not been clarified yet. We hypothesized that single nucleotide polymorphisms (SNPs) in genes related to the 1CM pathway may predict first-line treatment outcomes in mCRC patients. Methods Genomic DNA from blood samples of patients enrolled in two independent randomized phase III trials, TRIBE and FIRE-3, was genotyped through the OncoArray, a custom array manufactured by Illumina, including approximately 530K SNP markers. The impact on outcome of SNPs in six genes of the 1CM pathway (MTHFR, MTR, MTRR, MAT2A, SHMT, TYMS) was analyzed. Results A total of 451 patients were included. TRIBE FOLFIRI/bevacizumab (bev) arm served as discovery cohort (N = 215, mPFS/OS: 9.7/26.2 months), FIRE-3 FOLFIRI/bev arm as validation (N = 107, mPFS/OS: 11.5/31.4 months) and FOLFIRI/cetuximab arm as control (N = 129, mPFS/OS: 12.8/49.8 months). In the discovery cohort, the overall population carrying the SHMT rs1979277 A/A variant showed a shorter median PFS (8.1 vs 10.3 months) compared to patients with any G alleles both in univariate (HR 2.13; 95%CI, 1.19-3.79; P = 0.007) and in multivariable analysis (HR 2.03; 95%CI, 1.10-3.73; P = 0.023). Additionally, A/A carrier showed a shorter median OS (18.0 vs 27.9 months) both in univariate (HR 1.74; 95%CI, 1.00-3.01; P = 0.045) and in multivariable analysis (HR 2.14; 95%CI, 1.17-3.90; P = 0.013). These findings were validated in overall patients in FIRE-3 bev cohort in median OS (24.9 vs 36 months) both in univariate (HR 2.18; 95%CI, 0.96-4.96; P = 0.049) and in multivariable analysis (HR 3.61; 95%CI, 1.47-8.86; P = 0.005). No significant association was observed in the control arm. Conclusions Our results suggest for the first time that SNPs in the SHMT gene may have a prognostic and predictive value in mCRC patients. These findings may provide novel perspectives on the role of 1CM signaling in CRC and possibly contribute to open novel therapeutic options. Legal entity responsible for the study The authors. Funding This manuscript was partly supported by the National Cancer Institute (grant number P30CA014089), the Gloria Borges WunderGlo Foundation-The Wunder Project, the Dhont Family Foundation, the San Pedro Peninsula Cancer Guild, the Daniel Butler Research Fund, the Call to Cure Research Fund, and the Fong Research Project. Disclosure F. Loupakis: Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses: Amgen; Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution): Bayer; Advisory / Consultancy, Speaker Bureau / Expert testimony: Sanofi; Speaker Bureau / Expert testimony, Research grant / Funding (institution), Travel / Accommodation / Expenses: Roche; Research grant / Funding (institution), Travel / Accommodation / Expenses: Merck Serono. S. Stintzing: Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Amgen; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Bayer; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Lilly; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Merck KGaA; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Roche; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Sanofi; Honoraria (self), Travel / Accommodation / Expenses: Sirtex Medical; Advisory / Consultancy: Boehringer Ingelheim; Advisory / Consultancy, Travel / Accommodation / Expenses: Takeda. F. Battaglin: Travel / Accommodation / Expenses: Amgen; Travel / Accommodation / Expenses: Bayer. M.D. Berger: Travel / Accommodation / Expenses: Astellas Pharma; Research grant / Funding (institution): Merck KGaA. C. Cremolini: Honoraria (self): Amgen; Honoraria (self), Advisory / Consultancy: Bayer; Honoraria (self), Advisory / Consultancy: Roche; Advisory / Consultancy: Lilly; Research grant / Funding (self), Research grant / Funding (institution): Merck. A. Falcone: Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Amgen; Honoraria (self), Advisory / Consultancy: Lilly; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Merck; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Roche; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Servier; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Bayer; Advisory / Consultancy: Bristol-Myers Squibb; Research grant / Funding (institution): MSD; Research grant / Funding (institution): Sanofi. V. Heinemann: Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Amgen; Honoraria (self), Advisory / Consultancy: Baxalta; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Boehringer Ingelheim; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Celgene; Honoraria (self): Lilly; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Merck; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Roche; Honoraria (self), Advisory / Consultancy: Sanofi; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: SERVIER; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Sirtex Medical; Honoraria (self): Taiho Pharmaceutical; Advisory / Consultancy, Travel / Accommodation / Expenses: Bristol-Myers Squibb; Advisory / Consultancy: Halozyme; Advisory / Consultancy, Travel / Accommodation / Expenses: MSD; Research grant / Funding (institution): Shire. H.J. Lenz: Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Bayer; Honoraria (self): Boehringer Ingelheim; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Roche; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Merck Serono; Advisory / Consultancy: Pfizer; Travel / Accommodation / Expenses: CARIS. All other authors have declared no conflicts of interest.

Background The prognosis of brain metastases (BM) in colorectal cancer (CRC) is extremely poor, but the incidence is increasing. The performance of existing prognostic classifications such as recursive partitioning analysis (RPA) and graded prognostic assessment (GPA) has never been evaluated in this specific setting. Moreover, the development of nomograms for estimating survival in such patients could be extremely helpful for treating physicians. Patients and methods Between 2000 and 2013, data from 227 patients with BM from CRC were collected at 8 Italian institutions. Overall survival (OS) was estimated with the Kaplan–Meier method and statistical comparison between curves was performed using the log-rank test. The discriminative ability for OS of RPA and GPA was assessed by the Harrell C-index from univariable Cox models. Putative prognostic factors for OS were also studied by multivariable Cox analysis, using the Harrell C index to evaluate the model discriminative ability. After a backward variable selection, a nomogram was developed to predict median survival time from individual patient- and tumor-related characteristics. The nomogram was externally validated on an independent series. Results After a median follow-up of 59months, fifty percent of patients were still at risk at 5months. The C index was 0.594 and 0.607 for the RPA and GPA classifications, respectively. The C-index associated with the final multivariable Cox model used for developing the nomogram was 0.643; the favorable prognostic factors for survival were lower age ( p =0.061), better Karnofsky performance status ( p p p =0.035). The C index evaluated on the validation series was 0.733, even better than in the development series; also, the calibration of nomogram predictions was good. Conclusion The C-index associated to the nomogram model was slightly higher than that obtained for the RPA and GPA classifications. Most importantly, the very satisfactory results of nomogram validation on the external series, make us confident that our instrument may assist in prognostic assessment, treatment decision making, and enrollment into clinical trials.

Regorafenib is a multi-targeting kinase inhibitor approved for the treatment of metastatic colorectal cancer patients in refractory to standard chemotherapy. Similarly to sorafenib, this agent was originally developed as a RAF1 inhibitor. However, the kinase inhibitory profile is distinct from sorafenib. A broad-spectrum of kinase inhibition induces wide-range drug sensitivity, irrespective of mutation status of major oncogenes. This agent's main therapeutic effects are anti-angiogenesis and the remodeling of tumor microenvironment through several mechanisms of action. The dual blockade of VEGF receptors and TIE2 can lead to both additive anti-angiogenesis effects and the suggestive unique regulation of vessel stability. Additionally, it inhibits molecular escape pathways to VEGF inhibition (e.g., FGF, PIGF, and PDGF signaling), enabling its continuous antiangiogenic effect even in tumors resistant to VEGF inhibitors. Furthermore, regorafenib has the important effect of enhancing anti-tumor immunity via macrophage modulation. Based on this concept, clinical trials have been recently launched for the development of a combination strategy with immune checkpoint inhibitors. Contrary to regorafenib induced clinical benefits and advances in the novel strategy, currently no predictive biomarkers have been identified. In the present review, we revisit and summarize regorafenib's unique mechanisms of action. The review could highlight molecular insights and provide some perspective for the search of predictive biomarkers used in metastatic colorectal cancer patients treated with regorafenib.

Background Though molecular classifications have been well studied, targeted therapies for GC are still limited. CDH1 mutations are characteristics of genomically stable GC and associated with poor prognosis. Herein, to understand the specific mutation profile and enriched pathways in CDH1-mutated (MT) GC could help to discover novel drug targets. Methods GC (N = 1596) were analyzed by next-generation sequencing (NGS) and immunohistochemistry (Caris Life Sciences, Phoenix, AZ). Tumor mutational burden (TMB) was calculated based on somatic nonsynonymous mutation, and microsatellite instability (MSI) was evaluated by NGS of known MSI loci. Gene fusions were evaluated using Archer (N = 253) or Whole Transcriptome Sequencing (WTS, N = 96). Results The overall mutation frequency of CDH1 was 9.7%. A significant association of CDH1 mutations with cancer types (GC, 12% vs gastroesophageal junction adenocarcinoma, 2%), sex (female, 13% vs male, 8%), Lauren subtypes (diffuse, 27% vs intestinal, 1%) and younger age (58 vs 62) were observed (p 0) (57% vs. 73%, p Conclusions This is the largest study to explore the distinct genomic landscape in CDH1-MT GC. It indicates CDH1-MT GC patients could potentially benefit from agents targeting WRN, POT1, CDK12 and IGF1R, while immunotherapy may be of lower efficacy in this cohort based on lower CPS score. Efficiency of these therapeutic targets and enriched pathways in CDH1-MT GC warrant further investigation. Legal entity responsible for the study Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.

Background Although rare, the incidence of BM is increasing due to the improvement in metastatic CRC treatment and longer survival. Genomic analyses of small series revealed that BM can harbor potentially unique driver mutations. We aimed to comprehensively characterize the molecular profile of BM and explore the differences between BM vs other distant metastases (OM) and primary tumors (PT) in CRC. Methods Tumor samples from BM (n = 81), PT (n = 6898) and OM (n = 5918) were analyzed using NGS (TruSEQ on 45 genes or NextSEQ on 592 genes), in situ hybridization and immunohistochemistry (Caris Life Sciences, Phoenix, AZ). Tumor mutational burden (TMB) was calculated based on somatic nonsynonymous missense mutations, and microsatellite instability (MSI) was evaluated by NGS of known MSI loci. Results The most frequently mutated genes in BM were TP53 (80%), APC (73%), KRAS (68%), ARID1A (18%), PIK3CA (13%) and FBXW7 (9%). The most prevalent copy number increase was seen in CDX2 (20%), CCND2 (7%), FLT1 (7%), FLT3 (7%) and FOXO1 (7%). When compared to OM and PT, mutations in KRAS (BM: 68%, OM: 49%, PT: 48%), CDKN2A (5%, 1%, 1%), ERCC2 (2%, 0, 0) and HRAS (1%, 0, 0) were significantly higher in BM (P 17mut/MB) and MSI-high were seen in BM vs PT (2 vs 9% and 1 vs 8%, P=.049 and .031, respectively) but not compared to OM. No RSPO3 nor NTRK1 fusions were seen in BM (n = 5). Female gender was associated with younger age in BM (53.5 vs 62 yr, P=.0014) and OM (58.8 vs 60.2 yr, P Conclusions This is the largest and most extensive profiling study to investigate the molecular makeup of BM and the differences with PT and OM in CRC. Our data show distinct mutations and CNA characterizing BM and lower expression of immune related markers, supporting the rationale to develop tailored approaches to the treatment of this metastatic site. Legal entity responsible for the study The authors. Funding National Cancer Institute grant number P30CA014089, Gloria Borges WunderGlo Foundation-The Wunder Project, Dhont Family Foundation, San Pedro Peninsula Cancer Guild, Daniel Butler Research Fund, Call to Cure Research Fund and Fong Research Project. Disclosure J. Xiu: Full / Part-time employment: Caris Life Sciences. Y. Baca: Full / Part-time employment: Caris Life Sciences. R.M. Goldberg: Research grant / Funding (self), Travel / Accommodation / Expenses: Caris Life Sciences. A. Grothey: Travel / Accommodation / Expenses: Caris Life Sciences. A.F. Shields: Research grant / Funding (self), Travel / Accommodation / Expenses: Caris Life Sciences. A. Seeber: Advisory / Consultancy: Caris Life Sciences. M.E. Salem: Travel / Accommodation / Expenses: Caris Life Sciences. P.A. Philip: Travel / Accommodation / Expenses: Caris Life Sciences. J.L. Marshall: Advisory / Consultancy: Caris Life Sciences. W..M. Korn: Full / Part-time employment: Caris Life Sciences. H.J. Lenz: Travel / Accommodation / Expenses: Caris Life Sciences. All other authors have declared no conflicts of interest.

Aim: Many patients (pts) with biliary cancer present advanced and unresectable disease. TACE has been effective in prolonging survival of pts with hepatocellular carcinoma; the aim of this analysis is to assess its safety and efficacy in biliary cancer. Methods: We retrospectively collected data on pts with histologically-proven unresectable biliary cancer consecutively treated with TACE at our Institution. TACE was performed with infusion of 2 ml of microspheres preloaded with doxorubicin (50 mg) into the tumor-supplying vessels. The treatment was repeated at a minimum of 4-weeks interval. Follow-up investigations after 4 weeks included contrast-enhanced multislice spiral CT and laboratory control. Results: From January 2011 to December 2013 52 TACE (range 1-7 per pts) were performed in 23 pts with the following characteristics: M/F 10/13; median age 64 (range 32-78); intrahepatic cholangiocarcinoma: 18, extrahepatic cholangiocarcinoma: 3 and gallbladder cancer: 2; unifocal/multifocal disease 10/13; 14 pts presented a minimal extrahepatic disease. According to RECIST criteria, best hepatic response to treatment was complete response in 1 pts, partial response in 5 pts and stable disease in 17 pts. 2 pts became resectable and underwent liver resection after TACE. No hepatic progression was observed within 4 weeks after procedure, while 4 pts progressed in extrahepatic sites (17%). The treatment was well tolerated with no deaths and no acute liver failure. Only 1 pts had an hepatic abscess as major complication; all other pts experienced mild side effects as fever, nausea, general malaise, loss of appetite and abdominal pain (PES, Post Embolization Syndrome). This syndrome occurred in the first 72 hours after procedure and resolved with conservative therapy alone. At the time of analysis 12 pts are alive and 4 of them have not progressed yet. Data are still immature for survival analysis. Conclusions: TACE is an effective and safe procedure with a high local disease control rate in unresectable biliary tract cancer and might be able to improve the outcome in this setting. Further studies are needed to confirm these preliminary data and to set the better timing for TACE integration with systemic chemotherapy. Disclosure: All authors have declared no conflicts of interest.