Pathological complete response with anti-PD-1 therapy in a patient with microsatellite instable high, BRAF mutant metastatic colon cancer: a case report and review of literature.

Importance: Mismatch repair (MMR) and BRAF mutation status are established independent prognostic factors for colorectal cancer (CRC). MMR deficient tumors are considered to have better prognosis whereas BRAF mutation is associated with poor prognosis. Studies evaluating the combined effect of BRAF and MMR status suggest MSI-high and BRAF mutant patients have a poorer prognosis as compared to MSI-high and BRAF wild type patients.