Evolving strategies for the management of BRAF-mutant metastatic colorectal cancer

Detection of the BRAF V600E mutation has important genetic, prognostic, and therapeutic implications for patients with metastatic colorectal cancer (mCRC), as it aids in the identification of a subgroup of patients who derive little benefit from standard treatments and have an extremely poor prognosis. Secondary analyses of BRAF V600E-mutated subsets from multiple randomized clinical trials have demonstrated a lack of therapeutic benefit and poor prognosis with conventional cytotoxic chemotherapy doublets, highlighting the need for novel effective treatments for this subpopulation. In contrast to patients with BRAF V600E-mutated metastatic melanoma, only 5% of patients with BRAF V600E-mutated mCRC responded to BRAF inhibitor monotherapy in an early-phase trial. Basic science efforts to define resistance mechanisms to BRAF inhibition have generated new therapeutic approaches for these patients. As a result, the treatment landscape for mCRC with a BRAF V600E mutation has shifted dramatically in recent years. Promising clinical trials using combination therapies that inhibit the mitogen-activated protein kinase (MAPK) pathway and alternative active pathways have demonstrated major advances for patients with BRAF V600E-mutated mCRC.