Ovarian carcinomas (OC) arising in BRCA1 and BRCA2 mutation carriers demonstrate pronounced sensitivity to platinum-based therapy due to deficiency of double-strand break DNA repair.
BRCA2, a cancer susceptibility gene, has been widely studied in breast and ovarian carcinomas as mutation carriers for this gene are at a high risk for cancer development.
BRCA2 carries a risk of breast cancer similar to that of BRCA1, but is associated with a lower risk of ovarian cancer and a higher risk of male breast cancer.
A BRCA2 mutation was found in eight of 34 women with ovarian cancer and a family history of stomach cancer versus three of 75 women with ovarian cancer and a family history of ovarian cancer, but not of stomach cancer (odds ratio=7.4; 95% CI 1.8-30; P=0.004).
A further confounder pertains to the lifetime risk for ovarian cancer, which differs strikingly between BRCA1 mutation carriers, who show a 40-60% lifetime risk, and their BRCA2 counterparts, who carry a lifetime risk of approximately 12-15% for ovarian cancer.
A phase II study of the PARP inhibitor olaparib (AstraZeneca) for cancer patients with inherited BRCA1 and BRCA2 gene mutations confirmed earlier results showing clinical benefit for advanced breast and ovarian cancers, and demonstrated evidence of effectiveness against pancreatic and prostate cancers.
A role for BRCA2 in sporadic breast and ovarian cancer has been suggested by loss of heterozygosity (LOH) studies which show frequent LOH in the BRCA2 region at chromosome 13q12.
A second breast cancer susceptibility gene (BRCA2) operates in some of the same molecular pathways as BRCA1, and mutations of this gene predispose to breast and ovarian cancer and probably to other tumor types, including prostate cancer.