Sorting out the rif-(b)raf.

We know KRAS mutations are bad for colon cancer and that microsatellite instability leads to benefits with immunotherapy. This retrospective cohort study assessed for any potential role played by BRAF. Because why not? It helps us sort out melanomas, after all. Over 850 patients receiving definitive hepatectomy for colorectal cancer metastatic to the liver with information on both KRAS and BRAF status were identified in a U.S. multi-institutional genetic database. A KRAS mutation was present in 39% and a BRAF mutation in 5%, with no crossover. V600E-BRAF mutations were associated with significantly worse survival (HR 2.8), even more so that KRAS mutations, which have been notorious in colon cancer since the 90s. What’s more, those with BRAF mutations were over 3x more likely to occur in right-sided colon cancer, likely contributing to their recognized poorer prognoses. TBL: BRAF is the new KRAS for colon cancer. | Margonis, JAMA Surg 2018