Biomarkers in Cancer

Colorectal cancer (CRC) is still one of the deadliest cancer-related diseases. About 10% of CRC patients are characterized by a mutation in the B-Raf proto-oncogene serine/threonine kinase (BRAF) gene resulting in a valine-to-glutamate change at the residue 600 (V600E). This mutation is also present in more than 60% of melanoma patients. BRAF inhibitors were developed and found to improve patient survival; however, most patients at the end of the track ultimately develop resistance to these inhibitors. Melanoma patients benefit from the combination of BRAF inhibitors with mitogen/extracellular signal-regulated kinase (MEK) inhibitors, among others. Unfortunately, colorectal patients do not respond much efficiently, which suggests different resistance mechanisms between the two cancer types. This review aims at shedding light on recent discoveries that improve our understanding of the BRAF mutation biology in CRC.