Breast cancer susceptibility variants alter risk in familial ovarian cancer

Recent candidate gene and genome wide association studies have revealed novel loci associated with an increased risk of breast cancer. We evaluated the effect of these breast cancer associated variants on ovarian cancer risk in individuals with familial ovarian cancer both with and without BRCA1 or BRCA2 mutations. A total of 158 unrelated white British women (54 BRCA1/2 mutation positive and 104 BRCA1/2 mutation negative) with familial ovarian cancer were genotyped for FGFR2, TNRC9/TOX3 and CASP8 variants. The p.Asp302His CASP8 variant was associated with reduced ovarian cancer risk in the familial BRCA1/2 mutation negative ovarian cancer cases (P = 0.016). The synonymous TNRC9/TOX3 (Ser51) variant was present at a significantly lower frequency than in patients with familial BRCA1/2 positive breast cancer (P = 0.0002). Our results indicate that variants in CASP8 and TNRC9/TOX3 alter the risk of disease in individuals affected with familial ovarian cancer.