Fluoropyrimidine type, patient age, tumour sidedness and mutation status as determinants of benefit in patients with metastatic colorectal cancer treated with EGFR monoclonal antibodies: individual patient data pooled analysis of randomised trials from the ARCAD database.

BACKGROUND: KRAS mutations in metastatic colorectal cancer (mCRC) are used as predictive biomarkers to select therapy with EGFR monoclonal antibodies (mAbs). Other factors may be significant determinants of benefit. METHODS: Individual patient data from randomised trials with a head-to-head comparison between EGFR mAb versus no EGFR mAb (chemotherapy alone or best supportive care) in mCRC, across all lines of therapy, were pooled. Overall survival (OS) and progression-free survival (PFS) were compared between groups. Treatment effects within the predefined KRAS biomarker subsets were estimated by adjusted hazard ratio (HRadj) and 95% confidence interval (CI). EGFR mAb efficacy was measured within the KRAS wild-type subgroup according to BRAF and NRAS mutation status. In both KRAS wild-type and mutant subgroups, additional factors that could impact EGFR mAb efficacy were explored including the type of chemotherapy, line of therapy, age, sex, tumour sidedness and site of metastasis. RESULTS: 5675 patients from 8 studies were included, all with known mCRC KRAS mutation status. OS (HRadj 0.90, 95% CI 0.84-0.98, p = 0.01) and PFS benefit (HRadj 0.73, 95% CI 0.68-0.79, p < 0.001) from EGFR mAbs was observed in the KRAS wild-type group. PFS benefit was seen in patients treated with fluorouracil (HRadj 0.75, 95% CI 0.68-0.82) but not with capecitabine-containing regimens (HRadj 1.04, 95% CI 0.86-1.26) (pinteraction = 0.002). Sidedness also interacted with EGFR mAb efficacy, with survival benefit restricted to left-sided disease (pinteraction = 0.038). PFS benefits differed according to age, with benefits greater in those under 70 (pinteraction = 0.001). The survival benefit was not demonstrated in those patients with mutations found in the KRAS, NRAS or BRAF genes. The presence of liver metastases interacted with EGFR mAb efficacy in patients with KRAS mutant mCRC (pinteraction = 0.004). CONCLUSION: The benefit provided by EGFR mAbs in KRAS WT mCRC is associated with left-sided primary tumour location, younger patient age and absence of NRAS or BRAF mutations. Survival benefit is observed with fluorouracil but not capecitabine. Exploratory results support further research in KRAS mutant mCRC without liver metastases.

Immune checkpoint inhibitors for POLE or POLD1 proofreading-deficient metastatic colorectal cancer.

BACKGROUND: POLE and POLD1 proofreading deficiency (POLE/D1pd) define a rare subtype of ultramutated metastatic colorectal cancer (mCRC; over 100 mut/Mb). Disease-specific data about the activity and efficacy of immune checkpoint inhibitors (ICIs) in POLE/D1pd mCRC are lacking and it is unknown whether outcomes may be different from mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) mCRCs treated with ICIs. PATIENTS AND METHODS: In this global study, we collected 27 patients with mCRC harboring POLE/D1 mutations leading to proofreading deficiency and treated with anti-programmed cell death-ligand 1 alone +/- anti-cytotoxic T-lymphocyte antigen-4 agents. We collected clinicopathological and genomic characteristics, response, and survival outcomes after ICIs of POLE/D1pd mCRC and compared them with a cohort of 610 dMMR/MSI-H mCRC patients treated with ICIs. Further genomic analyses were carried out in an independent cohort of 7241 CRCs to define POLE and POLD1pd molecular profiles and mutational signatures. RESULTS: POLE/D1pd was associated with younger age, male sex, fewer RAS/BRAF driver mutations, and predominance of right-sided colon cancers. Patients with POLE/D1pd mCRC showed a significantly higher overall response rate (ORR) compared to dMMR/MSI-H mCRC (89% versus 54%; P = 0.01). After a median follow-up of 24.9 months (interquartile range: 11.3-43.0 months), patients with POLE/D1pd showed a significantly superior progression-free survival (PFS) compared to dMMR/MSI-H mCRC [hazard ratio (HR) = 0.24, 95% confidence interval (CI) 0.08-0.74, P = 0.01] and superior overall survival (OS) (HR = 0.38, 95% CI 0.12-1.18, P = 0.09). In multivariable analyses including the type of DNA repair defect, POLE/D1pd was associated with significantly improved PFS (HR = 0.17, 95% CI 0.04-0.69, P = 0.013) and OS (HR = 0.24, 95% CI 0.06-0.98, P = 0.047). Molecular profiling showed that POLE/D1pd tumors have higher tumor mutational burden (TMB). Responses were observed in both subtypes and were associated with the intensity of POLE/D1pd signature. CONCLUSIONS: Patients with POLE/D1pd mCRC showed more favorable outcomes compared to dMMR/MSI-H mCRC to treatment with ICIs in terms of tumor response and survival.

Plasmatic BRAF-V600E allele fraction as a prognostic factor in metastatic colorectal cancer treated with BRAF combinatorial treatments.

BACKGROUND: Combination of a BRAF inhibitor (BRAFi) and an anti-epidermal growth factor receptor (EGFR), with or without a MEK inhibitor (MEKi), improves survival in BRAF-V600E-mutant metastatic colorectal cancer (mCRC) over standard chemotherapy. However, responses are heterogeneous and there are no available biomarkers to assess patient prognosis or guide doublet- or triplet-based regimens. In order to better characterize the clinical heterogeneity observed, we assessed the prognostic and predictive role of the plasmatic BRAF allele fraction (AF) for these combinations. PATIENTS AND METHODS: A prospective discovery cohort including 47 BRAF-V600E-mutant patients treated with BRAFi-anti-EGFR ± MEKi in clinical trials and real-world practice was evaluated. Results were validated in an independent multicenter cohort (n= 29). Plasmatic BRAF-V600E AF cut-off at baseline was defined in the discovery cohort with droplet digital PCR (ddPCR). All patients had tissue-confirmed BRAF-V600E mutations. RESULTS: Patients with high AF have major frequency of liver metastases and more metastatic sites. In the discovery cohort, median progression-free survival (PFS) and overall survival (OS) were 4.4 and 10.1 months, respectively. Patients with high BRAF AF (≥2%, n = 23) showed worse PFS [hazard ratio (HR) 2.97, 95% confidence interval (CI) 1.55-5.69; P = 0.001] and worse OS (HR 3.28, 95% CI 1.58-6.81; P = 0.001) than low-BRAF AF patients (<2%, n = 24). In the multivariable analysis, BRAF AF levels maintained independent significance. In the validation cohort, high BRAF AF was associated with worse PFS (HR 3.83, 95% CI 1.60-9.17; P = 0.002) and a trend toward worse OS was observed (HR 1.86, 95% CI 0.80-4.34; P = 0.15). An exploratory analysis of predictive value showed that high-BRAF AF patients (n = 35) benefited more from triplet therapy than low-BRAF AF patients (n = 41; PFS and OS interaction tests, P < 0.01). CONCLUSIONS: Plasmatic BRAF AF determined by ddPCR is a reliable surrogate of tumor burden and aggressiveness in BRAF-V600E-mutant mCRC treated with a BRAFi plus an anti-EGFR with or without a MEKi and identifies patients who may benefit from treatment intensification. Our results warrant further validation of plasmatic BRAF AF to refine clinical stratification and guide treatment strategies.

Impact of age and gender on the safety and efficacy of chemotherapy plus bevacizumab in metastatic colorectal cancer: a pooled analysis of TRIBE and TRIBE2 studies.

BACKGROUND: The phase III TRIBE and TRIBE2 studies randomized metastatic colorectal cancer patients to first-line FOLFOXIRI/bevacizumab or a doublet (FOLFIRI or FOLFOX)/bevacizumab. The studies demonstrated a significant benefit from the triplet at the price of an increased incidence of chemotherapy-related adverse events (AEs). In both trials, males and females aged between 18 and 70 years with ECOG PS ≤2 and between 71 and 75 years with ECOG PS = 0 were eligible. We investigated the effect of FOLFOXIRI/bevacizumab versus doublets/bevacizumab according to age and gender. PATIENTS AND METHODS: Subgroup analyses according to age (<70 versus 70-75 years) and gender were carried out for overall response rate (ORR), progression-free survival (PFS), and AE rates. RESULTS: Of 1187 patients, 1005 (85%) were aged <70 years and 182 (15%) 70-75 years; 693 (58%) were males and 494 (42%) females. There was no evidence of interaction between age or gender and the benefit provided by the intensification of the upfront chemotherapy in terms of ORR and PFS, or the increased risk of experiencing G3/4 AEs. Elderly patients and females experienced higher rates of overall G3/4 AEs (73% versus 60%, P < 0.01 and 69% versus 57%, P < 0.01, respectively). Notably, in the FOLFOXIRI/bevacizumab subgroup, G3/4 diarrhea and febrile neutropenia occurred in 27% and 16% of elderly patients, respectively, while females reported high incidences of any grade nausea (67%) and vomiting (50%). CONCLUSIONS: The improvements in terms of ORR and PFS of FOLFOXIRI/bevacizumab versus doublets/bevacizumab are independent of gender and age, with a similar relative increase in AEs among elderly patients and females. Initial dose reductions and possibly primary G-CSF prophylaxis should be recommended for patients between 70 and 75 years old treated with FOLFOXIRI/bevacizumab, and a careful management of antiemetic prophylaxis should be considered among females.

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.

Temozolomide and irinotecan (TEMIRI regimen) as salvage treatment of irinotecan-sensitive advanced colorectal cancer patients bearing MGMT methylation.

Background: Non-randomized studies showed that temozolomide (TMZ) achieves an average 10% response rate in heavily pretreated metastatic colorectal cancer (mCRC) patients with promoter methylation of the DNA repair gene O6-methylguanine-DNA methyltransferase (MGMT). In this phase II trial, irinotecan and temozolomide (TEMIRI) combination regimen was assessed in irinotecan-sensitive, MGMT methylated/microsatellite stable (MSS) pretreated mCRC patients. Patients and methods: Key inclusion criteria were centrally confirmed MGMT methylation by methylation-specific PCR, MSS mCRC, progression after at least two prior chemotherapy regimens for advanced disease and irinotecan-free interval >3 months. TEMIRI (TMZ 150 mg/m2 on days 1-5 plus irinotecan 100 mg/m2 on days 1, 15 q28 days) was administered for six cycles, followed by maintenance with TMZ. The primary end point was overall response rate (ORR). Exploratory translational analyses included MGMT immunohistochemistry (IHC) and methyl-BEAMing (MB). Results: Between December 2014 and June 2017, 25 patients were enrolled. The primary end point was met, since six patients achieved a partial response [ORR 24%, 95% confidence interval (CI) 11% to 43%]. At a median follow-up of 15.6 months, median progression-free survival (mPFS) and overall survival (mOS) were 4.4 and 13.8 months, respectively. Only four (16%) patients had ≥ grade 3 (CTCAE 4.0) adverse events. All patients whose cancer was MGMT-positive IHC were non-responders. Consistently, patients with MGMT-negative/low tumors had a significantly longer mPFS than others (6.9 versus 2.0 months; hazard ratio = 0.29, 95% CI 0.02-0.41; P = 0.003) and a non-significant trend for longer mOS. MB testing showed similar accuracy. Conclusions: TEMIRI regimen is a safe and active option in pre-treated, irinotecan-sensitive mCRC patients with MGMT methylation.

Prognostic and predictive role of neutrophil/lymphocytes ratio in metastatic colorectal cancer: a retrospective analysis of the TRIBE study by GONO.

Background: Neutrophil/lymphocyte ratio (NLR), defined as absolute neutrophils count divided by absolute lymphocytes count, has been reported as poor prognostic factor in several neoplastic diseases but only a few data are available about unresectable metastatic colorectal cancer (mCRC) patients (pts). The aim of our study was to evaluate the prognostic and predictive role of NLR in the TRIBE trial. Patients and methods: Pts enrolled in TRIBE trial were included. TRIBE is a multicentre phase III trial randomizing unresectable and previously untreated mCRC pts to receive FOLFOXIRI or FOLFIRI plus bevacizumab. A cut-off value of 3 was adopted to discriminate pts with low (NLR < 3) versus high (NLR ≥ 3) NLR, as primary analysis. As secondary analysis, NLR was treated as an ordinal variable with three levels based on terciles distribution. Results: NLR at baseline was available for 413 patients. After multiple imputation at univariate analysis, patients with high NLR had significantly shorter progression-free survival (PFS) [hazard ratio (HR) 1.27 (95% CI 1.05-1.55), P = 0.017] and overall survival (OS) [HR 1.56 (95% CI 1.25-1.95), P < 0.001] than patients with low NLR. In the multivariable model, NLR retained a significant association with OS [HR 1.44 (95% CI 1.14-1.82), P = 0.014] but not with PFS [HR 1.18 (95% CI 0.95-1.46), P = 0.375]. No interaction effect between treatment arm and NLR was evident in terms of PFS (P for interaction = 0.536) or OS (P for interaction = 0.831). Patients with low [HR 0.84 (95% CI 0.64-1.08)] and high [HR 0.73 (95% CI 0.54-0.97)] NLR achieved similar PFS benefit from the triplet and consistent results were obtained in terms of OS [HR 0.83 (95% CI 0.62-1.12) for low NLR; HR 0.82 (95% CI 0.59-1.12) for high NLR]. Conclusion: This study confirmed the prognostic role of NLR in mCRC pts treated with bevacizumab plus chemotherapy in the first line, showing the worse prognosis of pts with high NLR. The advantage of the triplet is independent of NLR at baseline.

RET fusions in a small subset of advanced colorectal cancers at risk of being neglected.

Background: Recognition of rare molecular subgroups is a challenge for precision oncology and may lead to tissue-agnostic approval of targeted agents. Here we aimed to comprehensively characterize the clinical, pathological and molecular landscape of RET rearranged metastatic colorectal cancer (mCRC). Patients and methods: In this case series, we compared clinical, pathological and molecular characteristics of 24 RET rearranged mCRC patients with those of a control group of 291 patients with RET negative tumors. RET rearranged and RET negative mCRCs were retrieved by systematic literature review and by taking advantage of three screening sources: (i) Ignyta's phase 1/1b study on RXDX-105 (NCT01877811), (ii) cohorts screened at two Italian and one South Korean Institutions and (iii) Foundation Medicine Inc. database. Next-generation sequencing data were analyzed for RET rearranged cases. Results: RET fusions were more frequent in older patients (median age of 66 versus 60 years, P = 0.052), with ECOG PS 1-2 (90% versus 50%, P = 0.02), right-sided (55% versus 32%, P = 0.013), previously unresected primary tumors (58% versus 21%, P < 0.001), RAS and BRAF wild-type (100% versus 40%, P < 0.001) and MSI-high (48% versus 7%, P < 0.001). Notably, 11 (26%) out of 43 patients with right-sided, RAS and BRAF wild-type tumors harbored a RET rearrangement. At a median follow-up of 45.8 months, patients with RET fusion-positive tumors showed a significantly worse OS when compared with RET-negative ones (median OS 14.0 versus 38.0 months, HR: 4.59; 95% CI, 3.64-32.66; P < 0.001). In the multivariable model, RET rearrangements were still associated with shorter OS (HR: 2.97; 95% CI, 1.25-7.07; P = 0.014), while primary tumor location, RAS and BRAF mutations and MSI status were not. Conclusions: Though very rare, RET rearrangements define a new subtype of mCRC that shows poor prognosis with conventional treatments and is therefore worth of a specific management.

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.

Negative hyper-selection of metastatic colorectal cancer patients for anti-EGFR monoclonal antibodies: the PRESSING case-control study.

BACKGROUND: Refining the selection of metastatic colorectal cancer patients candidates for anti-epidermal growth factor receptor (EGFR) monoclonal antibodies beyond RAS and BRAF testing is a challenge of precision oncology. Several uncommon genomic mechanisms of primary resistance, leading to activation of tyrosine kinase receptors other than EGFR or downstream signalling pathways, have been suggested by preclinical and retrospective studies. PATIENTS AND METHODS: We conducted this multicentre, prospective, case-control study to demonstrate the negative predictive impact of a panel of rare genomic alterations [PRESSING (PRimary rESiStance IN RAS and BRAF wild-type metastatic colorectal cancer patients treated with anti-eGfr monoclonal antibodies) panel], including HER2/MET amplifications, ALK/ROS1/NTRK1-3/RET fusions and PIK3CA mutations. Hypothesizing a prevalence of candidate alterations of 15% and 0% in resistant and sensitive RAS and BRAF wild-type patients, respectively, with two-sided α and ß errors of 0.05 and 0.20, 47 patients per group were needed. RESULTS: Forty-seven patients per group were included. PRESSING panel alterations were significantly more frequent in resistant (24 out of 47, 51.1%) than in sensitive (1 out of 47, 2.1%) patients (P < 0.001) and in right- (12 out of 29, 41.4%) than left-sided (13 out of 65, 20.0%) tumours (P = 0.03). The predictive accuracy of PRESSING panel and sidedness was 75.3% and 70.2%, respectively. Among hyper-selected patients, right-sidedness was still associated with resistance (P = 0.002). The predictive accuracy of the combined evaluation of PRESSING panel and sidedness was 80.4%. As a secondary analysis, 8 (17.0%) resistant and 0 sensitive patients showed microsatellite instability (P < 0.001). CONCLUSION: The investigated panel of genomic alterations allows refining the selection of RAS and BRAF wild-type metastatic colorectal cancer patients candidates for anti-EGFRs, partially explaining and further corroborating the predictive ability of primary tumour sidedness.

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.

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.

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.

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.

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.

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.