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

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.