Refer to the Chemoprevention section of this summary for information about the use of tamoxifen as a risk-reduction strategy for CBC in BRCA mutation carriers.
Prognosis of BRCA1- and BRCA2-related ovarian cancer
Despite generally poor prognostic factors, several studies have found an improved survival among ovarian cancer patients with BRCA mutations.[280,281,282,283,284,285,286] A nationwide, population-based case-control study in Israel found 3-year survival rates to be significantly better for ovarian cancer patients with BRCA founder mutations, compared with controls. Five-year follow-up in the same cohort showed improved survival for carriers of both BRCA1 and BRCA2 mutations (54 months) versus noncarriers (38 months), which was most pronounced for women with stages III and IV ovarian cancer and for women with high-grade tumors. In a U.S. study of AJ women with ovarian cancer, those with BRCA mutations had a longer median time to recurrence and an overall improved survival, compared with both AJ women with ovarian cancer who did not have a BRCA mutation and two large groups of advanced-stage ovarian cancer clinical trial patients. In a retrospective U.S. hospital-based study, Ashkenazi BRCA mutation carriers had a better response to platinum-based chemotherapy, as measured by response to primary therapy, disease-free survival, and OS, compared with sporadic cases. Similarly, a significant survival advantage was seen in a case-control study among women with non-AJ BRCA mutations. A U.S. population-based study showed improvement in OS in BRCA2, but not in BRCA1, carriers. However, the study included only 12 BRCA2 mutation carriers and 20 BRCA1 mutation carriers. A study in Japanese patients found a survival advantage in stage III BRCA1-associated ovarian cancers treated with cisplatin regimens compared with nonhereditary cancers treated in a similar manner.
In contrast, several studies have not found improved OS among ovarian cancer patients with BRCA mutations.[226,290,291,292] A population-based study from Sweden noted an initial survival advantage in BRCA1-associated cases, but this advantage did not persist after 3 or 4 years. Similarly, a case-control study from the Netherlands found an improvement in short-term (up to 5 years) survival among women with familial ovarian cancer compared with sporadic controls, but no difference in longer-term survival. A study from the United Kingdom found a worse survival rate in ovarian cancer patients with a family history of ovarian cancer, whether or not they had a BRCA mutation, compared with sporadic controls. Finally, a case-control study at the University of Iowa failed to find any survival advantage for women with BRCA1 inactivation, whether by germline mutation, somatic mutation, or BRCA1 promoter silencing. In this study, however, cases (women with BRCA1 inactivation) were matched to controls on several variables, including tumor grade and p53 status, thus possibly minimizing any differences between the two groups.