A recent study published in the Journal of Clinical Oncology reported that besides breast and ovarian cancers in females, pathogenic variants (PV) in BRCA1 and BRCA2 are also associated with increased risks of male breast, pancreatic, and stomach cancers.
Several studies have suggested a plausible association of BRCA1/2 mutations with cancers other than female breast and ovarian cancers. However, precise risk estimations remained unclear due to relatively small sample sizes. Therefore, the researchers conducted a study on data from 5341 families with at least one family member who had a BRCA1 or BRCA2 PV and investigated the association between BRCA1/2 PVs and the risk of 22 cancers.
The PVs of BRCA1 were found to be associated with increased risk of male breast cancer (relative risk [RR], 4.30; 95% CI, 1.09-16.96), gallbladder cancer (RR, 3.34; 95% CI, 1.34-8.28), pancreatic cancer (RR, 2.36; 95% CI, 1.51-3.68), stomach cancer (RR, 2.17; 95% CI, 1.25-3.77), and colorectal cancer (RR, 1.48; 95% CI, 1.01- 2.16). Furthermore, BRCA2 PVs were associated with high risk of male breast cancer (RR, 44.0; 95% CI, 21.3-90.9), stomach cancer (RR, 3.69; 95% CI, 2.40-5.67), pancreatic cancer (RR, 3.34; 95% CI, 2.21-5.06), and prostate cancer (RR, 2.22; 95% CI, 1.63-3.03).
By age 80, the absolute risk for BRCA1 carriers was 0.4% for male breast cancer and 2.5% for pancreatic cancer. Additionally, for BRCA2 carriers, the risk for pancreatic and prostate cancer was 2.5% and 27%, respectively.
In conclusion, the study demonstrates that BRCA1/2 PV are associated with an increased risk of additional cancers along with female breast and ovarian cancers. Age-specific risk estimation will improve cancer management in BRCA1/2 patients.