Evolution of RAS Mutations in Cell-Free DNA of Patients with Tissue RAS Wild-Type Metastatic Colorectal Cancer Receiving First-Line Treatment: The PERSEIDA Study.

The serial analysis of cell-free DNA (cfDNA) enables minimally invasive monitoring of tumor evolution, providing continuous genetic information. PERSEIDA was an observational, prospective study assessing the cfDNA RAS (KRAS/NRAS) mutational status evolution in first-line, metastatic CRC, RAS wild-type (according to baseline tumor tissue biopsy) patients. Plasma samples were collected before first-line treatment, after 20 ± 2 weeks, and at disease progression. One hundred and nineteen patients were included (102 received panitumumab and chemotherapy as first-line treatment-panitumumab subpopulation). Fifteen (12.6%) patients presented baseline cfDNA RAS mutations (n = 14 [13.7%], panitumumab subpopulation) (mutant allele fraction ≥0.02 for all results). No patients presented emergent mutations (cfDNA RAS mutations not present at baseline) at 20 weeks. At disease progression, 11 patients (n = 9; panitumumab subpopulation) presented emergent mutations (RAS conversion rate: 19.0% [11/58]; 17.7% [9/51], panitumumab subpopulation). In contrast, three (5.2%) patients presenting baseline cfDNA RAS mutations were RAS wild-type at disease progression. No significant associations were observed between overall response rate or progression-free survival and cfDNA RAS mutational status in the total panitumumab subpopulation. Although, in patients with left-sided tumors, a significantly longer progression-free survival was observed in cfDNA RAS wild-type patients compared to those presenting cfDNA RAS mutations at any time. Continuous evaluation of RAS mutations may provide valuable insights on tumor molecular dynamics that can help clinical practice.

Prognostic Nomogram and Patterns of Use of FOLFIRI-Aflibercept in Advanced Colorectal Cancer: A Real-World Data Analysis.

INTRODUCTION: The VELOUR study evaluated the efficacy and safety of adding aflibercept to FOLFIRI (fluorouracil, leucovorin, irinotecan) in second-line therapy for metastatic colorectal cancer (mCRC). However, a nomogram that can stratify patients according to prognosis is unavailable, and the frequency and effect of the pragmatic use of modified schedules in actual practice remains unknown. METHOD: The sample consists of 250 patients with mCRC treated with aflibercept and irinotecan-based chemotherapy at nine Spanish academic centers between January 2013 and September 2015. The result of a Cox proportional hazards model regression for overall survival (OS), adjusted for covariates available in daily practice, was represented as a nomogram and web-based calculator. Harrell's c-index was used to assess discrimination. RESULTS: The prognostic nomogram for OS includes six variables: Eastern Cooperative Oncology Group performance status, tumor location, number of metastatic sites, mutational status, better response to previous treatment(s), and carcinoembryonic antigen. The model is well calibrated and has acceptable discriminatory capacity (optimism-corrected c-index, 0.723; 95% confidence interval [CI], 0.666-0.778). Median OS was 6.1 months (95% CI, 5.1-8.8), 12.4 months (95% CI, 9.36-14.8), and 22.9 months (95% CI, 16.6-not reached) for high-, intermediate-, and low-risk groups, respectively. Age, comorbidity, or use of modified FOLFIRI regimens did not affect prognosis in this series. Grade 3-4 adverse events were less common following modified schedules. The admission rate because of toxicity was higher in ≥65 years (9.7% vs. 19.6%; odds ratio, 2.26; p = .029). CONCLUSION: We have developed and internally validated a prognostic model for use in individuals with colorectal cancer initiating therapy with FOLFIRI-aflibercept to predict both OS and the effect of pragmatic modifications of the classic regime on efficacy and safety. This can aid in decision making and in designing future trials. IMPLICATIONS FOR PRACTICE: In this study, the authors developed and conducted the internal validation of a prognostic nomogram that makes it possible to stratify patients who are eligible for second-line FOLFIRI-aflibercept based on their probability of survival. This model was developed in a multicenter sample from nine Spanish hospitals. Furthermore, to increase the study's validity, the practical use of aflibercept in this setting was investigated, including doses or pragmatic modifications. The results suggest that the modified schedules often used in this daily clinical practice-based patient population are associated with less severe toxicity without apparent detriment to survival endpoints. It is believed that these data complement the information provided by the VELOUR trial and are relevant for the oncologist in treating colon cancer in the second-line setting.

Cancer chemotherapy reduces plasma total polyphenols and total antioxidants capacity in colorectal cancer patients.

Our aim was to investigate the effect of chemotherapy on plasma total antioxidant capacity and polyphenols in patients with colon cancer. Plasma samples were collected from 70 CRC patients under chemotherapy treatment, and 15 non-treated patients. The control group included 71 healthy individuals. Plasma ABTS and FRAP were measured as biomarkers of antioxidant total capacity and the total phenols as an indicator to determine the polyphenols levels in plasma. Treatment with chemotherapy protocols resulted in a significant decrease of ABTS (-24 %, p < 0.048), FRAP (-15 %, p < 0.046) and polyphenols (-46 %, p < 0.05) compared with the values of those not treated. The total antioxidant capacity was significantly lower (-18 % for ABTS and -12 % for FRAP) in patients with metastasis as compared with patients without metastasis. The plasma total phenols, were also decreased (-16 %, p = 0.005) in metastasis patients. The patients with colorectal cancer have decreased total antioxidant capacity and the values are lower in patients treated with chemotherapy. Furthermore, CEA tumor marker levels are associated with a lower plasma total antioxidant capacity, and therefore with the progress and development of the disease.