Primary tumor sidedness and benefit from FOLFOXIRI plus bevacizumab as initial therapy for metastatic colorectal cancer. Retrospective analysis of the TRIBE trial by GONO.

Background: Right-sided metastatic colorectal cancer (mCRC) patients have poor prognosis and achieve limited benefit from first-line doublets plus a targeted agent. In this unplanned analysis of the TRIBE study, we investigated the prognostic and predictive impact of primary tumor sidedness in mCRC patients and the differential impact of the intensification of the chemotherapy in subgroups defined according to both primary tumor sidedness and RAS and BRAF mutational status. Patients and methods: Patients were randomized to receive upfront 5-fluoruracil, leucovorin, and irinotecan (FOLFIRI) plus bevacizumab or 5-fluoruracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI) plus bevacizumab. Tumors were defined as right- or left-sided if they originated from the caecum to the transverse colon or within the splenic flexure and beyond, respectively. Patients with available information about both primary sidedness and RAS and BRAF status were included in the present analysis. Progression-free survival (PFS), overall survival (OS) and RECIST response rate were assessed according to tumor location and RAS and BRAF mutational status. Results: Information about primary sidedness and RAS and BRAF status was available for 358 (70.5%) out of 508 randomized patients. Patients with right-sided tumors (N = 173) presented shorter OS [23.7 versus 31.0 months, HR = 1.42 (95% CI 1.09-1.84), P = 0.010] and a trend toward shorter PFS [10.2 versus 11.5 months, HR = 1.24 (95% CI: 0.98-1.56), P = 0.083] than those with left-sided tumors (N = 185), but these associations were no longer evident when adjusting for RAS and BRAF status. Patients with right-sided tumors achieved more relative benefit from the intensification of the chemotherapy backbone in terms of both PFS (HR = 0.59 versus 0.89, P for interaction = 0.099) and OS (HR = 0.56 versus 0.99, P for interaction = 0.030) and this advantage was independent of their RAS and BRAF status. Conclusions: FOLFOXIRI plus bevacizumab may be regarded as a preferred first-line treatment option for clinically selected patients with right-sided metastatic colorectal cancer irrespective of their RAS and BRAF mutational status. Trial registration: clinicaltrials.gov identifier NCT00719797.

Genetic variants of DNA repair-related genes predict efficacy of TAS-102 in patients with refractory metastatic colorectal cancer.

Background: Tri-phosphorylated trifluridine (FTD) incorporation into DNA is TAS-102's main anti-tumor action. We tested whether genetic polymorphisms in homologous recombination (HR) and cell cycle checkpoint pathway for DNA repair is associated with outcomes in refractory metastatic colorectal cancer (mCRC) patients treated with TAS-102. Patients and methods: We analyzed genomic DNA extracted from 233 samples of three cohorts: an evaluation cohort of 52 patients receiving TAS-102, a validation cohort of 129 patients receiving TAS-102 and a control cohort of 52 patients receiving regorafenib. Single nucleotide polymorphisms of genes involved in HR (ATM, BRCA1, BRCA2, XRCC3, FANCD2, H2AX, RAD51) and cell cycle checkpoint (ATR, CHEK1, CHEK2, CDKN1A, TP53, CHE1, PIN1, PCNA) were analyzed by PCR-based direct sequencing. Results: In univariate analysis for the evaluation cohort, patients with any G allele in ATM rs609429 had longer overall survival (OS) than those with the C/C variant (8.7 vs. 4.4 months, HR 0.37, 95% CI: 0.14-0.99, P = 0.022). Patients carrying any A allele in XRCC3 rs861539 had significantly longer progression-free survival (PFS) (3.8 vs. 2.3 months, HR 0.44, 95% CI: 0.21-0.92, P = 0.024) and OS (15.6 vs. 6.3 months, HR 0.25, 95% CI: 0.08-0.79, P = 0.012) than those with the G/G variant. In multivariable analysis, ATM rs609429 remained significant for OS (P = 0.020). In the validation cohort, patients having ATM rs609429 with any G allele showed longer OS and PFS; the G/A variant in XRCC3 rs861539 showed longer OS, though without statistical significance. Conclusion: Genetic variants in the HR pathway may predict clinical outcome in mCRC patients receiving TAS-102.

Impact of genetic variations in the MAPK signaling pathway on outcome in metastatic colorectal cancer patients treated with first-line FOLFIRI and bevacizumab: data from FIRE-3 and TRIBE trials.

BACKGROUND: The MAPK-interacting kinase 1 (MKNK1) is localized downstream of the RAS/RAF/ERK and the MAP3K1/MKK/p38 signaling pathway. Through phosphorylation MKNK1 regulates the function of eukaryotic translation initiation factor 4E, a key player in translational control, whose expression is often upregulated in metastatic colorectal cancer patients (mCRC). Preclinical data suggest that MKNK1 increases angiogenesis by upregulating angiogenic factors. We therefore hypothesize that variations in the MKNK1 gene predict outcome in mCRC patients treated with first-line FOLFIRI and bevacizumab (bev). PATIENTS AND METHODS: A total of 567 patients with KRAS wild-type mCRC in the randomized phase III FIRE-3 and TRIBE trials treated with first-line FOLFIRI/bev (discovery and validation cohorts) or FOLFIRI and cetuximab (cet) (control cohort) were included in this study. Five single-nucleotide polymorphisms in the MAPK signaling pathway were analyzed. RESULTS: AA genotype carriers of the MKNK1 rs8602 single-nucleotide polymorphism treated with FOLFIRI/bev in the discovery cohort (FIRE-3) had a shorter progression-free survival (PFS) than those harboring any C (7.9 versus 10.3 months, Hazard ratio (HR) 1.73, P = 0.038). This association could be confirmed in the validation cohort (TRIBE) in multivariable analysis (PFS 9.0 versus 11.0 months, HR 3.04, P = 0.029). Furthermore, AA carriers in the validation cohort had a decreased overall response rate (25% versus 66%, P = 0.049). Conversely, AA genotype carriers in the control group receiving FOLFIRI/cet did not show a shorter PFS. By combining both FOLFIRI/bev cohorts the worse outcome among AA carriers became more significant (PFS 9.0 versus 10.5 months) in univariable (HR 1.74, P = 0.015) and multivariable analysis (HR 1.76, P = 0.022). Accordingly, AA carriers did also exhibit an inferior overall response rate compared with those harboring any C (36% versus 65%, P = 0.005). CONCLUSION: MKNK1 polymorphism rs8602 might serve as a predictive marker in KRAS wild-type mCRC patients treated with FOLFIRI/bev in the first-line setting. Additionally, MKNK1 might be a promising target for drug development.

Estimating 12-week death probability in patients with refractory metastatic colorectal cancer: the Colon Life nomogram.

Background: Regorafenib and TAS-102 have recently demonstrated statistically significant survival gains in patients with refractory metastatic colorectal cancer (mCRC). Life expectancy ≥12 weeks was an inclusion criterion in registrative trials, and the identification of proper clinical selection tools for the daily use of these drugs in heavily pre-treated patients is needed to improve the cost-benefit ratio. We aimed at building a nomogram able to predict death probability within 12 weeks from the date of assessment of refractory mCRC. Patients and methods: Four hundred eleven refractory mCRC patients with ECOG performance status (PS) ≤2 receiving regorafenib, TAS-102 or other treatments were used as developing set. Putative prognostic variables were selected using a random forest model and included in a binary logistic model from which the nomogram was developed. The nomogram was externally validated and its performance was evaluated by examining calibration (how close predictions were to the actual outcome) and discriminative ability (Harrell C index) both on developing (internal validation) and validating (external validation) sets. Results: Four variables were selected and included in the nomogram: PS (P < 0.0001), primary tumor resection (P = 0.027), LDH value (P = 0.0001) and peritoneal involvement (P = 0.081). In the developing set, the nomogram discriminative ability was high (C = 0.778), and was confirmed in the validating set (C = 0.778), where the overall outcome was better as a consequence of the enrichment in patients receiving regorafenib or TAS-102 (46% versus 34%; P < 0.0001). Conclusions: Our nomogram may be a useful tool to predict the probability of death within 12 weeks in patients with refractory mCRC. Based on four easy-to-collect variables, the 'Colon Life' nomogram and free app for smartphones may improve mCRC patients' selection for later-line therapies and assist researchers for the enrollment in clinical trials in this setting.

Variant alleles in factor V, prothrombin, plasminogen activator inhibitor-1, methylenetetrahydrofolate reductase and risk of thromboembolism in metastatic colorectal cancer patients treated with first-line chemotherapy plus bevacizumab.

Single-nucleotide polymorphisms (SNPs) related to hereditary thrombophilia were investigated as risk factors for thromboembolism in cancer patients. Their effect in metastatic colorectal cancer (mCRC) has never been explored so far. Our aim was to analyse the effect of coagulation factor V (FVL G1691A), prothrombin (PT G20210A), methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and plasminogen activator inhibitor type 1 (PAI-1 5G/4G) allelic variants in this setting. Fifty-two patients treated with first-line chemotherapy plus bevacizumab who developed a thromboembolic event in their lifetime were initially genotyped. A contemporary cohort of 127 patients who did not experience any thromboembolic event was also analysed. DNA was extracted from peripheral blood and genotypes were determined by real-time PCR, using LightSNiP (TIB MOLBIOL) on LightCcler 480 (Roche). The association between thromboembolism and SNPs was investigated by univariable and multivariable analyses. All SNPs were in Hardy-Weinberg equilibrium (χ2 test P>0.20). FVL G1691A and PT G20210A were present only in heterozygosis in 4 (2.2%) and 7 (3.9%) patients, respectively; MTHFR C677T in homozygosis in 29 (16.2%), MTHFR A1298C in homozygosis in 13 (7.3%); PAI-1 5G/4G in 98 (54.7%) and 4G/4G in 41 (23%) patients. At univariable analysis, treatment duration was significantly associated with thromboembolism (P<0.001), whereas gender, age, obesity, platelets count and chemotherapy backbone were not. Similarly, FVL G1691A and PT G20210A as well as MTHFR C677T and PAI-1 4G allele were significantly associated, whereas MTHFR A1298C was not. At multivariable model including PT G20210A, MTHFR C677T and PAI-1 4G (age, obesity, treatment duration and chemotherapy backbone were included as adjustment factors), the three SNPs were significantlty associated with higher risk of thromboembolism (P=0.025, <0.0001 and P=0.033, respectively). Further validation studies are warranted in order to design a prospective trial of thromboprophylaxis in mCRC patients with high-risk genotypes.

Glycolysis gene expression analysis and selective metabolic advantage in the clinical progression of colorectal cancer.

Production of lactate even in the presence of sufficient levels of oxygen (aerobic glycolysis) seems the prevalent energy metabolism pathway in cancer cells. The analysis of altered expression of effectors causing redirection of glucose metabolism would help to characterize this phenomenon with possible therapeutic implications. We analyzed mRNA expression of the key enzymes involved in aerobic glycolysis in normal mucosa (NM), primary tumor (PT) and liver metastasis (LM) of colorectal cancer (CRC) patients (pts) who underwent primary tumor surgery and liver metastasectomy. Tissues of 48 CRC pts were analyzed by RT-qPCR for mRNA expression of the following genes: hexokinase-1 (HK-1) and 2 (HK-2), embryonic pyruvate kinase (PKM-2), lactate dehydrogenase-A (LDH-A), glucose transporter-1 (GLUT-1), voltage-dependent anion-selective channel protein-1 (VDAC-1). Differences in the expression of the candidate genes between tissues and associations with clinical/pathologic features were studied. GLUT-1, LDH-A, HK-1, PKM-2 and VDAC-1 mRNA expression levels were significantly higher in PT/LM tissues compared with NM. There was a trend for higher expression of these genes in LM compared with PT tissues, but differences were statistically significant for LDH-A expression only. RAS mutation-positive disease was associated with high GLUT-1 mRNA expression levels only. Right-sided colon tumors showed significantly higher GLUT-1, PKM-2 and LDH-A mRNA expression levels. High glycolytic profile was significantly associated with poor prognosis in 20 metastatic, RAS-mutated pts treated with first-line chemotherapy plus Bevacizumab. Altered expression of effectors associated with upregulated glucose uptake and aerobic glycolysis occurs in CRC tissues. Additional analyses are warranted for addressing the role of these changes in anti-angiogenic resistance and for developing novel therapeutics.

CXCR4 polymorphism predicts progression-free survival in metastatic colorectal cancer patients treated with first-line bevacizumab-based chemotherapy.

We analyzed associations between CXCR4/CXCL12 single-nucleotide polymorphisms and outcomes in metastatic colorectal cancer (mCRC) patients who underwent first-line bevacizumab-based chemotherapy. A total of 874 patients were included in this study: 144 treated with bevacizumab and FOLFOX or XELOX (training cohort), 653 treated with bevacizumab and FOLFIRI or FOLFOXIRI (validation cohort A or B) and 77 treated with cetuximab- and oxaliplatin-based regimens (control cohort). One CXCR4 polymorphism (rs2228014) and two CXCL12 polymorphisms (rs1801157 and rs3740085) were analyzed by PCR-based direct sequencing. Patients with a C/C genotype had a prolonged progression-free survival (PFS) compared with those with any T allele (P=0.030) in the training cohort. Similarly, patients with the C/C genotype had a superior PFS in the validation cohorts, but not in the control cohort. Our findings suggest that a common genetic variant, CXCR4 rs2228014, could predict PFS and may guide therapeutic decisions in mCRC patients receiving first-line bevacizumab-based chemotherapy.

Challenging chemoresistant metastatic colorectal cancer: therapeutic strategies from the clinic and from the laboratory.

As survival has improved for patients with metastatic colorectal cancer (mCRC), there is an increasing need for effective and well-tolerated third-line and subsequent-lines of treatment. Despite recent advances with the development of new-targeted therapies in this setting, there remains an unmet need to exploit oncogenic drivers of colorectal cancer and overcome acquired resistance. Potential treatment strategies include revisiting old targets such as human epidermal growth factor receptor 2, RAS, and BRAF and investigating new targets such as c-MET, the PI3 kinase, and Wnt pathways, and also the use of immune-checkpoint inhibitors. Here, we review recent phase III trials exploring approved agents, early trials investigating new drugs for chemorefractory mCRC, and the potential of capturing tumour dynamics during its evolution by liquid biopsy analysis.

FOLFOXIRI or FOLFOXIRI plus bevacizumab as first-line treatment of metastatic colorectal cancer: a propensity score-adjusted analysis from two randomized clinical trials.

BACKGROUND: FOLFOXIRI plus bevacizumab is a valid option as upfront treatment for metastatic colorectal cancer (mCRC) patients. While several trials investigated the effect of combining bevacizumab with different chemotherapy regimens, including fluoropyrimidines monotherapy and oxaliplatin- or irinotecan-containing doublets, no randomized comparison assessing the impact of the addition of bevacizumab to FOLFOXIRI is available. PATIENTS AND METHODS: A total of 122 mCRC patients received first-line FOLFOXIRI in the phase III trial by the GONO (FOLFOXIRI group) and 252 patients received first-line FOLFOXIRI plus bevacizumab in the TRIBE trial (FOLFOXIRI plus bevacizumab group). A propensity score-adjusted method was adopted to provide an estimation of the benefit from the addition of bevacizumab to FOLFOXIRI in terms of survival and activity parameters. RESULTS: Patients in the FOLFOXIRI group had more frequently Eastern Cooperative Oncology Group performance status of one or two, high Köhne score, metachronous and liver-limited disease, had previously received adjuvant treatments and had their primary tumors resected. The median progression-free survival (PFS) was 12.3 months in the FOLFOXIRI plus bevacizumab group compared with 10.0 months in the FOLFOXIRI group {propensity score-adjusted hazard ratio (HR) 0.74 [95% confidence interval (CI) 0.59-0.94], P = 0.013}. This association was significant also in the multivariable model (P = 0.024). The median OS was 29.8 months in the FOLFOXIRI plus bevacizumab group compared with 23.6 months in the FOLFOXIRI group [propensity score-adjusted HR: 0.72 (95% CI 0.56-0.93), P = 0.014]. At the multivariable model, the addition of bevacizumab was still associated with significantly longer OS (P = 0.030). No significant differences in RECIST response rate (RR) [65.1% versus 55.7%; propensity score-adjusted odds ratio (OR): 1.29 (95% CI 0.81-2.05), P = 0.280], early RR [62.7% versus 57.8%; OR: 1.14 (95% CI 0.68-1.93), P = 0.619] and median depth of response (42.2% versus 53.8%, P = 0.259) were reported. CONCLUSIONS: Though in the absence of a randomized comparison, the addition of bevacizumab to FOLFOXIRI provides significant benefit in PFS and OS, thus supporting the use of FOLFOXIRI plus bevacizumab as upfront treatment for mCRC patients. TRIALS' NUMBERS: NCT01219920 and NCT00719797.

BRAF and RAS mutations as prognostic factors in metastatic colorectal cancer patients undergoing liver resection.

BACKGROUND: Despite major advances in the management of metastatic colorectal cancer (mCRC) with liver-only involvement, relapse rates are high and reliable prognostic markers are needed. METHODS: To assess the prognostic impact of BRAF and RAS mutations in a large series of liver-resected patients, medical records of 3024 mCRC patients were reviewed. Eligible cases undergoing potentially curative liver resection were selected. BRAF and RAS mutational status was tested on primary and/or metastases by means of pyrosequencing and mass spectrometry genotyping assay. Primary endpoint was relapse-free survival (RFS). RESULTS: In the final study population (N=309) BRAF mutant, RAS mutant and all wild-type (wt) patients were 12(4%), 160(52%) and 137(44%), respectively. Median RFS was 5.7, 11.0 and 14.4 months respectively and differed significantly (Log-rank, P=0.043). At multivariate analyses, BRAF mutant had a higher risk of relapse in comparison to all wt (multivariate hazard ratio (HR)=2.31; 95% CI, 1.09-4.87; P=0.029) and to RAS mutant (multivariate HR=2.06; 95% CI, 1.02-4.14; P=0.044). Similar results were obtained in terms of overall survival. Compared with all wt patients, RAS mutant showed a higher risk of death (HR=1.47; 95% CI, 1.05-2.07; P=0.025), but such effect was lost at multivariate analyses. CONCLUSIONS: BRAF mutation is associated with an extremely poor median RFS after liver resection and with higher probability of relapse and death. Knowledge of BRAF mutational status may optimise clinical decision making in mCRC patients potentially candidate to hepatic surgery. RAS status as useful marker in this setting might require further studies.

BRAF codons 594 and 596 mutations identify a new molecular subtype of metastatic colorectal cancer at favorable prognosis.

BACKGROUND: While the negative prognostic role of BRAF V600E mutation in metastatic colorectal cancer (mCRC) is well established, the impact of BRAF codons 594 and 596 mutations, occurring in <1% of CRCs, is completely unknown. The present work aims to describe clinical, pathological and molecular features and prognosis of BRAF codons 594 and 596 mutant mCRCs, compared with BRAF V600E mutant and wild-type ones. PATIENTS AND METHODS: Patients treated for mCRC at three Italian Institutions between October 2006 and October 2014, with available KRAS and NRAS codon 12, 13, 59, 61, 117 and 146 and BRAF codon 594, 596 and 600 mutational status, as detected by means of direct sequencing or matrix assisted laser desorption ionization time-of-flight MassArray, were included. RESULTS: Ten patients bearing BRAF codons 594 or 596 mutated tumors were identified and compared with 77 and 542 patients bearing BRAF V600E mutated and BRAF wild-type tumors, respectively. While BRAF V600E mutated tumors were more frequently right-sided, mucinous and with peritoneal spread, BRAF 594 or 596 mutated were more frequently rectal, nonmucinous and with no peritoneal spread. All BRAF 594 or 596 mutated tumors were microsatellite stable. Patients with BRAF codons 594 or 596 mutated tumors had markedly longer overall survival (OS) when compared with BRAF V600E mutated [median OS: 62.0 versus 12.6 months; hazard ratio: 0.36 (95% confidence interval 0.20-0.64), P = 0.002], both at univariate and multivariate analyses. CONCLUSIONS: BRAF codon 594 or 596 mutated mCRCs are different from BRAF V600E ones in terms of molecular features, pathological characteristics and clinical outcome. This is consistent with preclinical evidences of a kinase inactivating effect of these mutations. The role of CRAF in transducing the intracellular signal downstream BRAF 594 or 596 mutated proteins opens the way to further preclinical investigation.

Continuation or reintroduction of bevacizumab beyond progression to first-line therapy in metastatic colorectal cancer: final results of the randomized BEBYP trial.

BACKGROUND: The combination of bevacizumab with fluorouracil-based chemotherapy is a standard first-line treatment option in metastatic colorectal cancer (mCRC). We studied the efficacy of continuing or reintroducing bevacizumab in combination with second-line chemotherapy after progression to bevacizumab-based first-line therapy. PATIENTS AND METHODS: In this phase III study, patients with mCRC treated with fluoropyrimidine-based first-line chemotherapy plus bevacizumab were randomized to receive in second-line mFOLFOX-6 or FOLFIRI (depending on first-line regimen) with or without bevacizumab. The primary end point was progression-free survival. To detect a hazard ratio (HR) for progression of 0.70 with an α and ß error of 0.05 and 0.20, respectively, 262 patients were required. RESULTS: In consideration of the results of the ML18147 trial, the study was prematurely stopped. Between April 2008 and May 2012, a total of 185 patients were randomized. Bevacizumab-free interval was longer than 3 months in 43% of patients in chemotherapy alone arm and in 50% of patients in the bevacizumab arm. At a median follow-up of 45.3 months, the median progression-free survival was 5.0 months in the chemotherapy group and 6.8 months in the bevacizumab group [adjusted HR = 0.70; 95% confidence interval (CI) 0.52-0.95; stratified log-rank P = 0.010]. Subgroup analyses showed a consistent benefit in all subgroups analyzed and in particular in patients who had continued or reintroduced bevacizumab. An improved overall survival was also observed in the bevacizumab arm (adjusted HR = 0.77; 95% CI 0.56-1.06; stratified log-rank P = 0.043). Responses (RECIST 1.0) were similar in the chemotherapy and bevacizumab groups (17% and 21%; P = 0.573). Toxicity profile was consistent with previously reported data. CONCLUSIONS: This study demonstrates that the continuation or the reintroduction of bevacizumab with second-line chemotherapy beyond first progression improves the outcome and supports the use of this strategy in the treatment of mCRC. ClinicalTrials.gov number: NCT00720512.

Variations in genes regulating tumor-associated macrophages (TAMs) to predict outcomes of bevacizumab-based treatment in patients with metastatic colorectal cancer: results from TRIBE and FIRE3 trials.

BACKGROUND: Tumor-associated macrophages (TAMs) with the M2-like phenotype are regulated by mainly NF-kB pathway including TBK1, which can influence tumor progression by secretion of proangiogenic factors such as vascular endothelial growth factor. The CCL2/CCR2 axis, histidine-rich glycoprotein (HRG), and placenta growth factor (PIGF) play a critical role in the polarization of M1/M2 phenotypes and the recruitment of TAMs to tumor microenvironment. We therefore hypothesized that variations in genes involved in regulating TAMs may predict clinical outcomes of bevacizumab treatment in patients with metastatic colorectal cancer (mCRC). PATIENTS AND METHODS: We analyzed genomic DNA extracted from samples of patients receiving bevacizumab plus FOLFIRI as a first-line treatment using PCR-based direct sequencing. Twelve functional single-nucleotide polymorphisms in eight genes (CCL2, CCR2, HRG, PIGF, NFKB1, TBK1, CCL18, and IRF3) were tested for associations with clinical outcomes in a discovery cohort of 228 participants in TRIBE trial (NCT00719797), then validated in 248 KRAS exon2 (KRAS) wild-type participants in FIRE3 trial (NCT00433927). FIRE3-cetuximab cohort served as a negative control. RESULTS: TBK1 rs7486100 was significantly associated with overall survival in 95 KRAS wild-type patients of TRIBE cohort in univariate analysis and had a strong trend in multivariable analysis; furthermore, the association of the T allele was observed for progression-free survival (PFS) in both univariate and multivariable analyses in FIRE3-bevacizumab but not cetuximab cohort. CCL2 rs4586, CCL18 rs14304, and IRF3 rs2304205 had univariate and multivariable correlations with PFS in KRAS mutant patients of the TRIBE cohort, whereas they had no correlations in KRAS wild-type patients of the TRIBE cohort. No association was seen in control cohort. CONCLUSIONS: Our study demonstrates for the first time that variations in genes regulating TAMs-related functions are significantly associated with clinical outcomes in mCRC patients treated with bevacizumab-containing chemotherapy. These results also suggest that some TAM-related gene variations may predict outcomes of bevacizumab treatment in KRAS status-dependent manner.

Early tumor shrinkage and depth of response predict long-term outcome in metastatic colorectal cancer patients treated with first-line chemotherapy plus bevacizumab: results from phase III TRIBE trial by the Gruppo Oncologico del Nord Ovest.

BACKGROUND: Early tumor shrinkage (ETS) and depth of response (DoR) predict overall survival (OS) in first-line trials of chemotherapy ± anti-EGFR monoclonal antibodies in metastatic colorectal cancer (mCRC). These associations and the predictive accuracy of response measurements for survival parameters were investigated in the phase III TRIBE trial of FOLFOXIRI plus bevacizumab (bev) versus FOLFIRI plus bev. PATIENTS AND METHODS: A landmark approach was adopted to define the assessable population. The distribution of RECIST response rate, ETS and DoR was compared in the two arms. Associations between response measurements and progression-free survival (PFS), post-progression survival (PPS) and OS were tested by univariate and multivariate Cox models. Prediction performance of each factor was estimated by C-index. RESULTS: A significantly higher percentage of patients in the FOLFOXIRI plus bev arm achieved ETS ≥20%, when compared with the control arm (62.7% versus 51.9%, P = 0.025). Also the DoR was significantly higher in the triplet plus bev arm (43.4% versus 37.8%, P = 0.003). Both ETS and DoR were associated with PFS, PPS and OS at the univariate analyses and in the multivariate models stratified for other prognostic variables. Both ETS and DoR were able to predict survival as accurately as RECIST response. CONCLUSION: FOLFOXIRI plus bev improves ETS and DoR when compared with FOLFIRI plus bev. Achieving rapid and deep tumor shrinkage consistently delays tumor progression and prolongs survival in patients treated with first-line chemotherapy plus bev. ETS is a promising and valuable end point for clinical trials' design deserving further investigation.

Genes involved in pericyte-driven tumor maturation predict treatment benefit of first-line FOLFIRI plus bevacizumab in patients with metastatic colorectal cancer.

Pericytes are crucial for angiogenesis. The impact of pericyte function to bevacizumab efficacy in mCRC treatment has not been comprehensively examined. This retrospective study investigated germline polymorphisms in genes related to early pericyte maturation to predict bevacizumab efficacy in 424 patients of two clinical trials treated first line with FOLFIRI+bevacizumab. Eight single-nucleotide polymorphisms (SNPs) were tested for potential biomarker value: RGS5 (regulator of G-protein signaling 5; rs1056515, rs2661280), PDGFR-ß (platelet-derived growth factor receptor-ß; rs2229562, rs2302273), CSPG4 (chondroitin sulfate proteoglycan NG2; rs8023621, rs1127648) and RALBP1 (RalA binding protein 1; rs10989, rs329007). For progression-free survival (PFS), PDGFR-ß (rs2302273) was able to define significantly different patient cohorts in uni- and multivariate testing. RALPB1 (rs329007) showed predictive value for tumor response. The C allele in RGS5 (rs2661280) predicted longer overall survival and CSPG4 rs1127648 was associated with differences in PFS, but for both value was lost when multivariate analysis was applied. A comprehensive statistical analysis revealed that the biomarker value of the SNPs was dependent on primary tumor location. This is the first study to identify pericyte germline polymorphisms associated with clinical outcome in mCRC patients treated first line with FOLFIRI+bevacizumab. The differences seen with regard to primary tumor location may lead to further research to understand the clinical outcome differences seen in right- and left-sided colon cancer.

Genetic variants of kinase suppressors of Ras (KSR1) to predict survival in patients with ERα-positive advanced breast cancer.

In patients with breast cancer (BC), deregulation of estrogen receptor (ERα) activity may account for most resistance to endocrine therapies. Our previous study used a whole-human kinome siRNA screen to identify functional actors in ERα modulation and showed the implication of proteins kinase suppressors of ras (KSR1). From those findings we evaluated the clinical impact of KSR1 variants in patients with ERα+ BC treated with TAM. DNA was obtained from 222 patients with advanced ERα+ BC treated with TAM who had undergone surgery from 1981 to 2003. We selected three potentially functional relevant KSR1 polymorphisms; two within the 3'UTR (rs224190, rs1075952) and one in the coding exon 7 (rs2293180). The primary end points were overall survival (OS) and disease-free survival (DFS). After a 6.4-year median follow-up, patients carrying the rs2241906 TT genotype showed shorter DFS (2.1 vs 7.1 years, P=0.005) and OS (2.6 vs 8.4 years P=0.002) than those with the TC or TT genotypes. Those associations remained significant in the multivariable analysis adjusting age, lymph node status, LMTK3 and IGFR variants and HER2 status. The polymorphisms rs2241906 and rs1075952 were in linkage disequilibrium. No association was shown between rs2293180 and survival. Among the actors of ERα signaling, KSR1 rs2241906 variants may predict survival in patients with advanced ERα+ BC treated with adjuvant TAM.

Distinct gene expression profiles of proximal and distal colorectal cancer: implications for cytotoxic and targeted therapy.

Colorectal cancer (CRC) is a heterogeneous disease with genetic profiles and clinical outcomes dependent on the anatomic location of the primary tumor. How location has an impact on the molecular makeup of a tumor and how prognostic and predictive biomarkers differ between proximal versus distal colon cancers is not well established. We investigated the associations between tumor location, KRAS and BRAF mutation status, and the messenger RNA (mRNA) expression of proteins involved in major signaling pathways, including tumor growth (epidermal growth factor receptor (EGFR)), angiogenesis (vascular endothelial growth factor receptor 2 (VEGFR2)), DNA repair (excision repair cross complement group 1 (ERCC1)) and fluoropyrimidine metabolism (thymidylate synthase (TS)). Formalin-fixed paraffin-embedded tumor specimens from 431 advanced CRC patients were analyzed. The presence of seven different KRAS base substitutions and the BRAF V600E mutation was determined. ERCC1, TS, EGFR and VEGFR2 mRNA expression levels were detected by reverse transcriptase-PCR. BRAF mutations were significantly more common in the proximal colon (P<0.001), whereas KRAS mutations occurred at similar frequencies throughout the colorectum. Rectal cancers had significantly higher ERCC1 and VEGFR2 mRNA levels compared with distal and proximal colon tumors (P=0.001), and increased TS levels compared with distal colon cancers (P=0.02). Mutant KRAS status was associated with lower ERCC1, TS, EGFR and VEGFR2 gene expression in multivariate analysis. In a subgroup analysis, this association remained significant for all genes in the proximal colon and for VEGFR2 expression in rectal cancers. The mRNA expression patterns of predictive and prognostic biomarkers, as well as associations with KRAS and BRAF mutation status depend on primary tumor location. Prospective studies are warranted to confirm these findings and determine the underlying mechanisms.

Integrin genetic variants and stage-specific tumor recurrence in patients with stage II and III colon cancer.

Integrins (ITGs) are key elements in cancer biology, regulating tumor growth, angiogenesis and lymphangiogenesis through interactions of the tumor cells with the microenvironment. Moving from the hypothesis that ITGs could have different effects in stage II and III colon cancer, we tested whether a comprehensive panel of germline single-nucleotide polymorphisms (SNPs) in ITG genes could predict stage-specific time to tumor recurrence (TTR). A total of 234 patients treated with 5-fluorouracil-based chemotherapy at the University of Southern California were included in this study. Whole-blood samples were analyzed for germline SNPs in ITG genes using PCR-restriction fragment length polymorphism or direct DNA sequencing. In the multivariable analysis, stage II colon cancer patients with at least one G allele for ITGB3 rs4642 had higher risk of recurrence (hazard ratio (HR)=4.027, 95% confidence interval (95% CI) 1.556-10.421, P=0.004). This association was also significant in the combined stage II-III cohort (HR=1.975, 95% CI 1.194-3.269, P=0.008). The predominant role of ITGB3 rs4642 in stage II diseases was confirmed using recursive partitioning, showing that ITGB3 rs4642 was the most important factor in stage II diseases. In contrast, in stage III diseases the combined analysis of ITGB1 rs2298141 and ITGA4 rs7562325 allowed to identify three distinct prognostic subgroups (P=0.009). The interaction between stage and the combined ITGB1 rs2298141 and ITGA4 rs7562325 on TTR was significant (P=0.025). This study identifies germline polymorphisms in ITG genes as independent stage-specific prognostic markers for stage II and III colon cancer. These data may help to select subgroups of patients who may benefit from ITG-targeted treatments.

Role of immunoglobulin G fragment C receptor polymorphism-mediated antibody-dependant cellular cytotoxicity in colorectal cancer treated with cetuximab therapy.

Antibody-dependent cellular cytotoxicity (ADCC), which is activated by effector cells via immunoglobulin G (IgG) fragment C receptors (FcRs), was proposed as a mechanism of cetuximab efficacy. Peripheral blood mononuclear cells (PBMCs) from 23 healthy donors and 13 patients with metastatic colorectal cancer (mCRC) treated with cetuximab were tested for FcγR polymorphisms and cetuximab-mediated ADCC. ADCC was measured by chromium-51 release on a epidermal growth factor receptor (EGFR)-positive human colon cancer cell line. Overall, 86 mCRC patients were genotyped for study purposes. PBMCs harbouring the FcγRIIIa 158 V/V genotype had a significantly higher cetuximab-mediated ADCC. No correlation was found between FcγR polymorphisms and response rate or time to progression after cetuximab-based therapy. Despite the in vitro analysis showing that the FcγRIIIa 158 V/V genotype is associated with higher ADCC, clinical data do not support a predictive role of FcγRIIIa polymorphisms in mCRC treated with cetuximab.

Gender-specific profiling in SCN1A polymorphisms and time-to-recurrence in patients with stage II/III colorectal cancer treated with adjuvant 5-fluoruracil chemotherapy.

This study was designed to analyze the gender-related association between SCN1A polymorphisms (voltage-gated sodium channels; α-subunit) and time-to-recurrence (TTR) in patients with colorectal cancer (CRC) treated with 5-fluoruracil (5-FU)-based adjuvant chemotherapy. We enrolled from a prospective database patients with stage II and III CRC treated with adjuvant 5-FU-based chemotherapy. Genotypes for SCN1A rs3812718 and rs229877 were determined by direct DNA sequencing. One hundred twenty-seven males and 107 females were included in the study. In the univariate and multivariate analysis, the shortest TTR was associated with female patients carrying the rs3812718-TT genotype (hazard ratio (HR): 2.26 (95% confidence interval (CI): 0.89, 5.70), P=0.039) but with male patients carrying the rs3812718-CC genotype (HR: 0.49 (95% CI: 0.18, 1.38), P=0.048). For rs229877 the CT genotype was associated with a trend for shorter TTR in both gender populations. The study validated gender-dependent association between genomic SCN1A rs3812718 polymorphism and TTR in CRC patients treated with adjuvant 5-FU-based chemotherapy. This study confirms that voltage-gated Na+ channels may be a potential therapeutic target and a useful predictive biomarker before 5-FU infusion.