In a new study published online in JAMA Oncology, researchers have discovered that the removal of the ovaries can reduce breast cancer death by 62 percent in women diagnosed with breast cancer and carrying a BRCA1 gene mutation.
Women who carry a germline mutation in either the BRCA1 or BRCA2 gene face a lifetime risk of breast cancer of up to 70 percent. Once they are diagnosed, they face high risks of both second primary breast and ovarian cancer. Other past studies of BRCA gene mutation carriers have found reduced mortality associated with oophorectomy (removal of the ovaries) for women with a history of breast cancer.
The study, performed by Steven A. Narod, M.D. and Kelly Metcalfe, Ph.D., of the Women's College Research Institute, Toronto, Canada, and coauthors, sought to confirm these eailier observations in a group of women with BRCA1 and BRCA2 gene mutations and early-stage breast cancer. The study included 676 women, of whom 345 underwent the oophorectomy procedure after being diagnosed with breast cancer, while the remaining 331 retained both ovaries.
The study found that the 20-year survival for the entire group was 77.4 percent. In the entire group, there was a 56 percent reduction in breast cancer death associated with oophorectomy. In women with the BRCA1 mutation, there was a significant reduction of 62 percent in breast cancer death, but in women with the BRCA2 mutation, the reduction was far lower at only 43 percent.
According to the study, oophorectomies were performed an average of six years after the women were diagnosed with breast cancer. For 70 of the women with the BRCA1 mutation who had their ovaries removed within two years of the breast cancer diagnosis, there was a 73 percent reduction in death compared to women who did not undergo an oophorectomy.
"It is important that follow-up studies be performed on women who undergo oophorectomy as part of their initial treatment, in particular, those women who undergo oophorectomy in the first year after diagnosis. It is also important that our observations be confirmed in other study populations. Further data are needed, in particular for BRCA2 carriers in order to confirm the benefit of oophorectomy in this population," article concludes.
Mary L. Disis, M.D., editor-in-chief of JAMA Oncology, writes: "The results provide a validation of the role of oophorectomy in conveying both a disease-free and overall survival benefit for BRCA1 mutation carriers. Oophorectomy after the primary diagnosis of breast cancer significantly reduced breast cancer-specific mortality in women with BRCA1 mutations but not in BRCA2 mutation carriers. In the entire group, oophorectomy was particularly effective for survival benefit in women with estrogen receptor-negative breast cancer. ... The data reported here are compelling and suggest that the potential of oophorectomy should become part of the treatment discussion at the time of diagnosis for BRCA mutation carriers with early-stage breast cancers."
