Federica Marmorino

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.

Histopathologic evaluation of liver metastases from colorectal cancer in patients treated with FOLFOXIRI plus bevacizumab.

Background:The FOLFOXIRI regimen produces a high rate of radiological and histopathological responses. Bevacizumab added to chemotherapy showed an improvement in pathological response and necrosis of colorectal liver metastases (CLMs). FOLFOXIRI plus bevacizumab produced promising early clinical results and is under investigation in several randomised trials, although no data are currently available on its effects on response of CLMs and on liver toxicities.Methods:Starting from 499 patients enrolled in first-line phase II/III trials, we selected on the basis of tissue sample availability 18 patients treated with FOLFOXIRI/XELOXIRI and 24 patients treated with FOLFOXIRI plus bevacizumab who underwent secondary resection of CLMs. The 28 untreated patients who underwent primary resection of CLMs were included as control group. Responses of CLMs and chemotherapy-induced toxicities were assessed.Results:Among the patients, 63% of those treated with FOLFOXIRI plus bevacizumab, as compared with 28% of those treated with only FOLFOXIRI/XELOXIRI, showed a histopathological response (P=0.033). In the two groups, 52% and 12.5%, respectively, showed necrosis ⩾50% (P=0.017). The incidence of liver toxicities was not significantly increased in patients treated with FOLFOXIRI plus bevacizumab.Conclusion:The addition of bevacizumab to FOLFOXIRI produces high rates of pathologic responses and necrosis of CLM without increasing liver toxicity.

Location of Primary Tumor and Benefit From Anti-Epidermal Growth Factor Receptor Monoclonal Antibodies in Patients With RAS and BRAF Wild-Type Metastatic Colorectal Cancer

INTRODUCTION Right- and left-sided colorectal cancers (CRCs) differ in clinical and molecular characteristics. Some retrospective analyses suggested that patients with right-sided tumors derive less benefit from anti-epidermal growth factor receptor (EGFR) antibodies; however, molecular selection in those studies was not extensive. PATIENTS AND METHODS Patients with RAS and BRAF wild-type metastatic CRC (mCRC) who were treated with single-agent anti-EGFRs or with cetuximab-irinotecan (if refractory to previous irinotecan) were included in the study. Differences in outcome between patients with right- and left-sided tumors were investigated. RESULTS Of 75 patients, 14 and 61 had right- and left-sided tumors, respectively. None of the right-sided tumors responded according to RECIST, compared with 24 left-sided tumors (overall response rate: 0% vs. 41%; p = .0032), and only 2 patients with right-sided tumors (15%) versus 47 patients with left-sided tumors (80%) achieved disease control (p < .0001). The median duration of progression-free survival was 2.3 and 6.6 months in patients with right-sided and left-sided tumors, respectively (hazard ratio: 3.97; 95% confidence interval: 2.09-7.53; p < .0001). CONCLUSION Patients with right-sided RAS and BRAF wild-type mCRC seemed to derive no benefit from single-agent anti-EGFRs. IMPLICATIONS FOR PRACTICE Right- and left-sided colorectal tumors have peculiar epidemiological and clinicopathological characteristics, distinct gene expression profiles and genetic alterations, and different prognoses. This study assessed the potential predictive impact of primary tumor site with regard to anti-epidermal growth factor receptor (EGFR) monoclonal antibody treatment in patients with RAS and BRAF wild-type metastatic colorectal cancer. The results demonstrated the lack of activity of anti-EGFRs in RAS and BRAF wild-type, right-sided tumors, thus suggesting a potential role for primary tumor location in driving treatment choices.

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-102s 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.

Activity and Safety of Cetuximab Plus Modified FOLFOXIRI Followed by Maintenance With Cetuximab or Bevacizumab for RAS and BRAF Wild-type Metastatic Colorectal Cancer: A Randomized Phase 2 Clinical Trial

Importance The combination of a triple-drug chemotherapy regimen with an anti–epidermal growth factor receptor (EGFR) agent as a first-line treatment of metastatic colorectal cancer (mCRC) showed promising activity along with safety concerns in single-arm phase 2 trials. The role of maintenance following chemotherapy and anti-EGFR and the optimal regimen to be adopted are not established. Objectives To evaluate the activity and safety of cetuximab plus modified FOLFOXIRI (mFOLFOXIRI) and explore the role of maintenance with cetuximab or bevacizumab in RAS and BRAF wild-type mCRC. Design, Setting, and Participants In a prospective, noncomparative, open-label, multicenter, randomized phase 2 trial, patients aged 18 to 75 years with unresectable, previously untreated RAS and BRAF wild-type (before amendment, KRAS wild-type) mCRC were recruited from 21 oncology units in Italy from October 19, 2011, to March 1, 2015 (followed up through May 31, 2017). In total, 323 patients were screened and 143 were randomized to 2 treatment arms to receive as a first-line induction a regimen of mFOLFOXIRI plus cetuximab followed by cetuximab (arm A) or bevacizumab (arm B) until disease progression. Primary analyses were conducted in a modified intention-to-treat population. Interventions mFOLFOXIRI plus cetuximab repeated every 2 weeks for up to 8 cycles, followed by maintenance with cetuximab or bevacizumab until disease progression. Main Outcomes and Measures The primary end point was the 10-month progression-free rate (PFR); secondary end points included progression-free and overall survival, response rate, rate of metastases resection, and adverse events. Results Of 143 patients randomized, 116 (81.1%) (median [interquartile range (IQR)] age, 59.5 [53-67] years; 34 [29.3%] women) had RAS and BRAF wild-type mCRC. At a median (IQR) follow-up of 44.0 (30.5-52.1) months, 10-month PFRs were 50.8% (90% CI, 39.5%-62.2%) in arm A and 40.4% (90% CI, 29.4%-52.1%) in arm B. The overall response rate was 71.6% (95% CI, 62.4%-79.5%). Main grade 3/4 adverse events were neutropenia (occurring in 36 patients [31%]), diarrhea (in 21 patients [18%]), skin toxic effects (in 18 patients [16%]), asthenia (in 11 patients [9%]), stomatitis (in 7 patients [6%]), and febrile neutropenia (in 3 patients [3%]). Conclusions and Relevance Although neither of the 2 arms met the primary end point, the findings indicate that a 4-month induction regimen of mFOLFOXIRI plus cetuximab is feasible and provides relevant activity results, leading to a high surgical resection rate. Trial Registration clinicaltrials.gov Identifier: NCT02295930

Serum LDH predicts benefit from bevacizumab beyond progression in metastatic colorectal cancer

Background:Different antiangiogenics are currently indicated in the second-line treatment of metastatic colorectal cancer (mCRC), following a first-line bevacizumab-containing treatment. The magnitude of benefit is limited, but no predictors of benefit have been identified.Methods:A total of 184 mCRC patients progressing to a first-line bevacizumab-containing treatment were randomised in the BEBYP study to continue or not the antiangiogenic in combination with a second-line chemotherapy. A subgroup analysis according to baseline serum lactate dehydrogenase (LDH) levels was carried out.Results:A significant interaction effect between LDH levels and treatment was found in terms of progression-free survival (PFS; P=0.002). Although patients with low LDH levels achieved significant PFS benefit from the continuation of bevacizumab (HR: 0.39 (95% CI: 0.23–0.65)), patients with high levels did not (HR: 1.10 (95% CI: 0.74–1.64)). Consistent results were reported in overall survival (OS; P=0.075).Conclusions:As preclinical evidence suggests that serum LDH may be a marker of tumour angiogenesis activation, low levels may indicate that bevacizumab is still efficacious in inhibiting angiogenesis. Validation of present results in subgroup analyses of other randomised trials of second-line angiogenesis inhibitors is warranted.

TAS-102 for the treatment of metastatic colorectal cancer

The survival of patients with metastatic colorectal cancer has notably increased in the past 20 years, from 12 months to around 30 months. Nevertheless, the prognosis of patients pretreated with all available agents is poor and there is high unmet need for newer treatments. TAS-102 is an orally administered combination of the nucleoside analogue trifluridine and tipiracil hydrochloride, a thymidine phosphorylase inhibitor. In a randomized trial of 800 patients who had received at least two other treatments previously (most patients had received more than four treatments). TAS-102 demonstrated a significant prolongation of overall survival compared with placebo (median survival 7.1 vs. 5.3 months; hazard ratio 0 · 68, 95%CI: 0 · 58–0 · 81; p < 0 · 001). The toxicity was manageable, grade 3 or higher events occurred in 69% of patients in the TAS-102 group versus 52% in the placebo group, with neutropenia the most common event.

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.

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.

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.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 vs 31.0 months, HR = 1.42 [95%CI, 1.09-1.84], P=0.010) and a trend toward shorter PFS (10.2 vs 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 vs. 0.89, P-for-interaction=0.099) and OS (HR = 0.56 vs. 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.