Somatic BRAF V600E Mutation in Familial Colorectal Cancer Type X: A New Study in Central Iran

Abstract

Background: BRAF-V600E is a known prognostic/predictive marker in colorectal cancer (CRC), detected in 4 - 12% of all patients with this cancer. Familial-CRC-type-X (FCCX) is a subtype of mismatch-repair (MMR) proficient CRC with an unknown genetic cause. Objectives: Given the lack of enough information on the molecular aspects of FCCX among Iranians, this study was conducted to evaluate the BRAF-V600E hot-spot mutation in tumor DNA in FCCX probands in Central Iran. Methods: This was a cross-sectional study in which 48 FCCX probands were recruited according to Amsterdam-II criteria, and MMR proficiency was confirmed by MSI testing and IHC-MMRs. Tumors’ DNA samples were assessed for the BRAF-V600E mutation by Sanger-sequencing. Results: None of the 48 assessed FCCX probands presented the BRAF-V600E mutation. Conclusions: It can be suggested that FCCX tumors have a good prognosis compared to other CRCs.