BRAF V600E-Mutated Metastatic Colorectal Cancer: Practical Management in the Post-BREAKWATER Era

BRAF V600E-mutated metastatic colorectal cancer (mCRC) is a biologically distinct subtype characterized by right-sided predominance, frequent overlap with serrated-pathway biology, and historically poor outcomes with conventional chemotherapy. Therapeutic progress has been driven by the recognition that BRAF inhibition alone is inadequate in colorectal cancer because adaptive epidermal growth factor receptor (EGFR)-mediated feedback rapidly restores MAPK signaling.

This narrative review evaluates the clinical development and practical integration of BRAF-targeted therapy in BRAF V600E-mutated mCRC, with particular emphasis on first-line treatment, MMR/MSI status, patient fitness, and treatment sequencing in the post-BREAKWATER era.

Combined BRAF and EGFR inhibition established encorafenib plus cetuximab as a standard option after prior therapy. The phase 3 BREAKWATER program has now moved BRAF-targeted treatment into first-line practice by demonstrating improved outcomes with encorafenib plus cetuximab combined with fluoropyrimidine-basedchemotherapy, including mFOLFOX6 and FOLFIRI backbones. These data define a chemo-targeted approach for fit patients with non-MSI-H/dMMR disease. For MSI-H/dMMR tumors, first-line immune checkpoint blockade should be prioritized irrespective of BRAF V600E status unless immunotherapy is absolutely contraindicated.

Important uncertainties remain regarding whether BRAF/EGFR targeting should be added to immunotherapy in MSI-H/dMMR disease, as well as the management of frail or oxaliplatin-ineligible patients, maintenance therapy, local treatment integration, and sequencing after frontline encorafenib exposure. Treatment selection in the post- BREAKWATER era should therefore integrate molecular context, patient fitness, and remaining evidence gaps.