According to an article recently published in Lancet Oncology, a prophylactic bilateral oophorectomy may be associated with an increased risk of death among premenopausal women who do not receive subsequent estrogen. However, further study is necessary to confirm this association.
A bilateral oophorectomy is a surgical procedure in which both ovaries are removed. Because the ovaries produce the majority of estrogen in premenopausal women and the majority of breast cancers are stimulated to grow from estrogen exposure, some women who are at an extremely elevated risk of developing breast cancer have their ovaries removed to prevent the development of the disease. In addition, some women who are at an increased risk of developing ovarian cancer also select a prophylactive oophorectomy.
Quality of life issues surrounding prophylactic oophorectomies have been studied; however, mortality rates among women undergoing this procedure have not been extensively evaluated.
Researchers from the Mayo Clinic recently analyzed data among women who underwent a preventive oophorectomy and compared their findings with data on women who had not undergone the procedure. This study included 1,293 women who had one of their ovaries removed (unilateral oophorectomy), 1,097 women who had both ovaries removed (bilateral oophorectomy), and 2,390 who never had an oophorectomy. None of the women in this study had cancer prior to the surgery.
- Overall mortality was not increased among women who underwent a bilateral oophorectomy compared to those who did not undergo the procedure.
- Mortality was higher among women who underwent a bilateral oophorectomy before the age of 45 years; this increase in mortality was mainly confined to women who did not received subsequent treatment with estrogen up to the age of 45 years.
- There were no mortality differences among women who underwent a unilateral oophorectomy compared to women who had not undergone the procedure.
The researchers concluded that women who undergo a preventive bilateral oophorectomy are not at an overall increased risk of mortality; however, premenopausal women undergoing the procedure with no subsequent estrogen supplementation may be at an increased risk of mortality. The researchers caution that further study is necessary to truly confirm these findings.
Women who are at a high risk of developing breast cancer due to genetics may wish to speak with their physician regarding their individual risks and benefits of undergoing a preventive oophorectomy.
Reference: Rocca W, Grossardt B, Andrade M, et al. Survival Patterns after Oophoprectomy in Premenopausal Women: A Population-Based Cohort Study. Lancet Oncology. Early online publication September, 2006. DOI:10.1016/S1470-2045(06)70869-5.