Treatment outcomes of patients with BRAFV600E-mutated metastatic colorectal cancer: a Polish retrospective cohort study.

Abstract

Introduction: The BRAF^V600E mutation is found in 6-11% of metastatic colo-rectal cancer (mCRC) patients. According to international guidelines for BRAF^V600E-mutated mCRC, the triplet chemotherapy FOLFOXIRI (folinic acid, 5-fluorouracil, oxaliplatin, irinotecan) or double chemotherapy with or without bevacizumab, and encorafenib plus cetuximab should be considered in the first- and second-line settings. We aimed to evaluate clinical practices in BRAF^V600E-mutated mCRC patients treated at five Polish oncology centers.

Material and methods: We retrospectively analyzed the data of BRAF^V600E- mutated mCRC patients treated between 2011 and 2023. Before starting the first-line treatment, all patients were tested for BRAF and RAS mutations.

Results: One hundred twenty-six patients (median age: 68 years; 55% female, 45% male) from five oncology centers were included. The majority of patients (69, 55%) had a right-sided primary tumor. The first line of chemotherapy was received by 100 patients (79.4%). The majority received doublet chemotherapy: FOLFOX (folinic acid, 5-fluorouracil, oxaliplatin), FOLFIRI (folinic acid, 5-fluorouracil, irinotecan), XELOX (capecitabine, oxaliplatin), and FOLFIRI with bevacizumab: 30 (30%), 47 (47%), 5 (5%), and 3 (3%). Only three patients received FOLFOXIRI; one patient received bevacizumab. The median duration of first-line treatment was 5.26 months (95% CI: 0.03-18.9). Subsequently, 40%, 16%, 5%, and 1% of patients received second, third, fourth, and fifth-line therapy, retrospectively. During the median follow-up of 38.5 months, 96 (79.3%) patients died. The median overall survival from the time of mCRC diagnosis was 13.7 months (95% CI: 11.3-17.6).

Conclusions: This study highlights the unmet need for effective treatment strategies for patients with BRAF^V600E-mutated mCRC in Poland.