ATLANTA — Salpingo-oophorectomy appears to significantly reduce the incidence of gynecologic cancers in all women with BRCA mutations and the incidence of breast cancer in women with BRCA2 mutations.
This conclusion is based on the results of a multicenter, prospective study presented at the annual meeting of the American Society of Clinical Oncology.
After about 3 years of follow-up, the 546 women who elected to receive risk-reducing salpingo-oophorectomy had a 90% reduction in gynecologic cancers and a 47% reduction in breast cancer incidence compared with the 325 women who chose not receive surgery. However, the risk reduction in breast cancer was limited to women with BRCA2 mutations.
“BRCA1 and BRCA2 cause related but distinct cancer susceptibility syndromes,” explained Dr. Noah D. Kauff in his presentation. He therefore thought it was important to examine the benefit of risk-reducing salpingo-oophorectomy in each population.
In all, 597 women with breast tissue at risk at the start of follow-up were included in the breast cancer risk analysis. Among women carrying the BRCA1 mutation, 15 of 190 patients treated with risk-reducing salpingo-oophorectomy developed breast cancer, compared with 19 of 178 patients not treated with surgery, a 39% risk reduction that was not statistically significant.
Among BRCA2 carriers, the incidence with surgery vs. surveillance was 4 of 113 patients and 9 of 116 patients, respectively, resulting in a significant 72% reduction in cancer risk.
The study, led by Dr. Kauff, of the Memorial Sloan-Kettering Cancer Center in New York, evaluated two prospective cohorts of women carrying a BRCA mutation. Compared with women who chose not to receive risk-reducing salpingo-oophorectomy, those treated with surgery were significantly older (mean age, 47 vs. 43 years), were more likely to have had breast cancer in the past (59% vs. 46%), were more likely to have taken hormone therapy (11% vs. 7%), and were significantly more likely to have given birth (83% vs. 74%).
An exploratory analysis showed an overall 78% risk reduction in estrogen receptor-positive cancer, compared with no significant change in the incidence of ER-negative breast cancer.
“Since most breast cancers related to BRCA1 mutations are ER-negative, it could be postulated that hormonal manipulation—in this case, risk-reducing salpingo-oophorectomy—might not be effective in this population,” said Dr. Banu Arun in her discussion of the study.
Dr. Arun, of the department of breast medical oncology at the University of Texas M.D. Anderson Cancer Center, Houston, suggested that future prospective studies should evaluate risk-reducing salpingo-oophorectomy plus a nonhormonal preventive agent, such as cyclooxygenase-2 inhibitors, retinoids, statins, or other agents, for women with BRCA1 mutations.