Abstract P3-08-01: The prospective risk of ovarian cancer in 1433 women in a breast cancer family history clinic: no increased risk in families testing negative for BRCA1 and BRCA2

Since the identification of the BRCA1 and BRCA2 genes speculation has continued regarding the breast and ovarian cancer risk associated with mutations in these genes. Also, as to whether mutations in these genes account for the majority of the association between breast and ovarian cancer. Identification of RAD51C and RAD51D mutations in breast/ovarian cancer families has reawakened the debate as to whether it is safe to reassure women from BRCA negative families that they are not at increased risk of ovarian cancer. 1433 women from breast cancer families that had tested negative for BRCA1/2 were followed for a total of between 0.04 and 25 years and checked against a cancer registry for ovarian cancer incidence. Data was censored at ovarian cancer diagnosis, oophorectomy or death. During 16358 women years of follow up no invasive epithelial ovarian cancer occurred, although 2 borderline tumors were diagnosed. Expected rates for this cohort from cancer registry data were 2.75 epithelial ovarian tumors with 2.52 for invasive cancer and 0.23 for borderline tumors. The upper confidence limit for invasive RR was 1.3 and for borderline tumors 0.97–31. In conclusion this the largest prospective follow up of a BRCA negative cohort has demonstrated that there is no increase in risk of invasive ovarian cancer in families that have tested negative for BRCA1/2. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-08-01.