The Prognostic Value of Locoregional Interventions for BRAF V600E Metastatic Colorectal Cancer: A Retrospective Cohort Analysis

A comprehensive overview of the molecular features and therapeutic targets in BRAFV600E-mutant colorectal cancer

As one of the most prevalent digestive system tumours, colorectal cancer (CRC) poses a significant threat to global human health. With the emergence of immunotherapy and target therapy, the prognosis for the majority of CRC patients has notably improved. However, the subset of patients with BRAF exon 15 p.V600E mutation (BRAFV600E) has not experienced remarkable benefits from these therapeutic advancements. Hence, researchers have undertaken foundational investigations into the molecular pathology of this specific subtype and clinical effectiveness of diverse therapeutic drug combinations. This review comprehensively summarised the distinctive molecular features and recent clinical research advancements in BRAF-mutant CRC. To explore potential therapeutic targets, this article conducted a systematic review of ongoing clinical trials involving patients with BRAFV600E-mutant CRC.

BRAF mutations and survival with surgery for colorectal liver metastases: A systematic review and meta-analysis

INTRODUCTION

Mutations in the BRAF gene (BRAFmut) are associated with an unfavorable prognosis in patients with metastatic colorectal cancer (CRC). The aim of this meta-analysis was to evaluate the prognosis of colorectal cancer (CRC) patients with liver metastases and the potential benefits of liver resection in patients with BRAFmut CRC.

MATERIAL AND METHODS

A systematic search of PubMed, Cochrane Central Controlled Trials, and Embase databases was conducted on May 31, 2023. The inclusion criteria were as follows:1) reporting of outcomes in patients with BRAFmut CRC who underwent surgery for liver metastases and/or comparison of outcomes between those who underwent and those who did not undergo resection; 2) reporting of survival information as hazard ratios (HR); and 3) publication in English.

RESULTS

34 studies were included. Median follow up was 48 months for prognostic BRAF status meta-analysis. BRAFmut status showed a significantly increased risk of mortality (hazard ratio [HR] = 2.56, 95% confidence interval [CI] 2.04-3.22; P < 0.01) and relapse (HR = 1.97, 95% CI 1.44-2.71; P < 0.01). Resection of liver metastases was associated with a survival benefit (median follow up 46 months). The HR for survival was 0.44 (95% confidence interval [CI] 0.33-0.59; P < 0.01) in favor of surgery.

CONCLUSIONS

and Relevance: Our analysis indeed confirms that BRAF mutation is associated with poor survival outcomes after liver resection of CRC metastases. However, upon quantitatively assessing the survival benefit of surgical intervention in patients with BRAF-mutated CRC liver metastases, we identified a significant 56% reduction in the risk of death.

Resectability, conversion, metastasectomy and outcome according to RAS and BRAF status for metastatic colorectal cancer in the prospective RAXO study

Background

Outcomes after metastasectomy for metastatic colorectal cancer (mCRC) vary with RAS and BRAF mutational status, but their effects on resectability and conversion rates have not been extensively studied.

Methods

This substudy of the prospective RAXO trial included 906 patients recruited between 2011 and 2018. We evaluated repeated centralised resectability assessment, conversion/resection rates and overall survival (OS), according to RAS and BRAF status.

Results

Patients included 289 with RAS and BRAF wild-type (RAS and BRAFwt), 529 with RAS mutated (RASmt) and 88 with BRAF mutated (BRAFmt) mCRC. Metastatic prevalence varied between the RAS and BRAFwt/RASmt/BRAFmt groups, for liver (78%/74%/61%), lung (24%/35%/28%) and peritoneal (15%/15%/32%) metastases, respectively. Upfront resectability (32%/29%/15%), conversion (16%/13%/7%) and resection/local ablative therapy (LAT) rates (45%/37%/17%) varied for RASa and BRAFwt/RASmt/BRAFmt, respectively. Median OS for patients treated with resection/LAT (n = 342) was 83/69/30 months, with 5-year OS-rates of 67%/60%/24%, while systemic therapy-only patients (n = 564) had OS of 29/21/15 months with 5-year OS-rates of 11%/6%/2% in RAS and BRAFwt/RASmt/BRAFmt, respectively. Resection/LAT was associated with improved OS in all subgroups.

Conclusions

There were significant differences in resectability, conversion and resection/LAT rates according to RAS and BRAF status. OS was also significantly longer for RAS and BRAFwt versus either mutant. Patients only receiving systemic therapy had poorer long-term survival, with variation according to molecular status.

Clinical trial registration

NCT01531621/EudraCT2011-003158-24