Family History Of Breast Cancer In Non-Brca Male Breast Cancer: A Case-Control Study.

e13032Background: Approximately 85% of male breast cancer (MBC) patients test negative for a BRCA mutation, and the role of genetic predisposition is unclear. Cancer risk counseling for unaffected relatives of BRCA-negative MBC patients relies on accurate cancer risk estimates, but there is limited data on the risk of breast cancer (BC) for relatives of these men. We characterized the association between MBC and family history of BC in patients who test negative for BRCA mutations in order to facilitate cancer risk counseling and to explore the possibility of unidentified MBC susceptibility alleles. Methods: We performed a case-control study of patients who had full length sequencing and large-rearrangement analysis for germline mutations in BRCA1/2 or the mismatch repair (MMR) genes at a commercial laboratory from 2006-2012. Cases were MBC patients who tested negative for a BRCA1/2 mutation (n = 3,647); controls were male colon cancer patients who tested negative for mutations in MMR genes (n = 4,269). I...