Removal of Ovaries and Fallopian Tubes Cuts Cancer Risk for BRCA1/2 Carriers
Adapted from the NCI Cancer Bulletin.Surgery that removes the ovaries and fallopian tubes, called salpingo-oophorectomy, is one of the most effective ways to decrease a woman's risk of breast and gynecologic cancer if she carries a BRCA1 or BRCA2 gene mutation. However, the true degree of risk reduction has not been precisely defined. A new meta-analysis of 10 independent studies has revealed with greater confidence than ever before that the risk reduction of this surgery can be 80 percent for ovarian or fallopian tube cancer and 50 percent for breast cancer. The full results of the analysis appeared in the January 21, 2009, Journal of the National Cancer Institute (see the journal abstract).
A team of researchers led by Dr. Timothy R. Rebbeck of the University of Pennsylvania looked at overall breast cancer risk, breast cancer risk according to BRCA mutation, and ovarian or fallopian cancer risk. Women who had BRCA1 mutations and women who had BRCA2 mutations benefited equally in terms of breast cancer risk after the surgery, according to their analysis. The authors pointed out, however, that this conflicts with results from their previous prospective cohort study which indicated that the surgery may have more benefit for BRCA2 mutation carriers.
“[Studies] that used retrospective cohort or case-control approaches did not observe this difference, and therefore, there was no difference in the pooled estimates,” they wrote, noting that the issue deserves further investigation. Data were not available for the meta-analysis to make this BRCA-type distinction for gynecologic cancer risk after the surgery.
In a related editorial, Drs. Mark H. Greene and Phuong L. Mai of National Cancer Institute's Division of Cancer Epidemiology and Genetics commended the study authors, noting that their attempt to “disentangle potential differences between BRCA1 and BRCA2 mutation carriers who, despite having superficial similarities with regard to phenotype, have important biological differences” strengthens the findings of their report. “The risk estimates presented in the study represent the most accurate current measures of potential benefits from risk-reducing salpingo-oophorectomy,” said Dr. Greene, “and genetics providers should use them in their daily practice.”