According to results presented at the 2006 annual meeting of the American Society of Clinical Oncology (ASCO), preventive removal of the ovaries and fallopian tubes reduces the risk of breast and ovarian cancer in women with BRCA1 or BRCA2 gene mutations. The reduction in breast cancer risk, however, was greatest among women with a BRCA2 mutation.
Inherited mutations in two genes-BRCA1 and BRCA2-have been found to greatly increase the lifetime risk of developing breast and ovarian cancer. Alterations in these genes can be passed down through either the mother’s or father’s side of the family. While it’s important to note that BRCA1 and BRCA2 alterations account for only a small proportion of all breast and ovarian cancers, some families may benefit from genetic testing.
Among women with a BRCA1 or BRCA2 mutation, preventive removal of the fallopian tubes and ovaries (risk-reducing salpingo-oophorectomy, or RRSO) has been shown to reduce the risk of developing breast and ovarian cancer. Previous studies of RRSO, however, have reported results after relatively short periods of follow-up, and have enrolled too few women to assess differences in risk reduction by type of BRCA mutation (BRCA1 vs. BRCA2).
To overcome these limitations, researchers pooled information across studies and assessed cancer risk in 886 female BRCA1 or BRCA2 mutation carriers over the age of 30. Women were enrolled from one of 11 study centers between 1994 and 2004. Women chose to participate in either a surveillance-only group (325 women) or RRSO (561 women). Median follow-up time was 40 months.
- Among all women combined, RRSO reduced the risk of breast cancer by 47% and reduced the risk of ovarian cancer by 89%.
- RRSO reduced the risk of breast cancer by 39% among women with a BRCA1 mutation and by 72% among women with a BRCA2 mutation.
- RRSO reduced the risk of ovarian cancer by 87% among women with a BRCA1 mutation. Among women with a BRCA2 mutation, two women in the observation group and none of the women in the RRSO group developed ovarian cancer.
These findings confirm that preventive removal of the ovaries and fallopian tubes reduces the risk of breast and ovarian cancer among women with BRCA mutations. The results also suggest that the extent of the protection against specific cancers may vary by type of mutation.
Reference: Kauff ND , Domchek SM, Friebel TM et al. Multi-center Prospective Analysis of Risk-reducing Salpingo-oophorectomy to Prevent BRCA-associated Breast and Ovarian Cancer. Presented at the 2006 ASCO Annual Meeting. Abstract 1003.