Preventive Oophorectomy Contraindicated in Women With an Average Risk of Ovarian Cancer

Researchers at the Mayo Clinic are recommending that premenopausal women with a low risk of ovarian cancer should be spared unnecessary comorbidities associated with bilateral oophorectomy.

The procedure, which involves removal of both ovaries, is used as a preventive measure against ovarian cancer. For their retrospective analysis, the researchers used data from the Rochester Epidemiology Project (REP) records-linkage system to identify premenopausal women under 50 years of age who had a bilateral oophorectomy between January 1, 1988 and December 31, 2007. Age-matched controls used in the study were women who had not undergone oophorectomy.

The primary outcome measured was the accumulation of 18 common chronic conditions over a 14-year follow-up period. Having manually abstracted information on demographics, reproductive history, family history of cancer, and life habits, along with ICD-9 codes entered by any healthcare institution participating in the REP, the authors had documented data on baseline conditions that the women were suffering from.

The analysis showed that while women who underwent the procedure already suffered from a higher multimorbidity burden prior to their oophorectomy, their risk of subsequent multimorbidity increased following the oophorectomy. The authors adjusted the data for the 18 chronic conditions observed at baseline, in addition to adjusting for variables of race/ethnicity, education, body mass index, smoking, age at baseline, and calendar year at baseline. Following this normalization, their analysis found that women younger than 46 years who had a preventive oophorectomy were at an increased risk of the following chronic conditions:

• Depression
• Hyperlipidemia
• Cardiac arrhythmias
• Coronary artery disease
• Arthritis
• Asthma
• Chronic obstructive pulmonary disease
• Osteoporosis

Further, when all 18 chronic conditions were considered together, the rate of accumulation accelerated following the removal of ovaries, with a hazard ratio of 1.22 (P<.001).

“This study provides new and stronger evidence against the use of bilateral oophorectomy for prevention in young women,” Walter Rocca, MD, lead author of the study, said in a statement. “Bilateral oophorectomy should not be considered an ethically acceptable option for the prevention of ovarian cancer in the majority of women who do not carry a high-risk genetic variant.”

The accumulation of multimorbidities has been proposed as a sign of accelerated aging and sex steroids, such as estrogen, are known to regulate the aging process. Using estrogen levels as a proxy for aging, the authors found that women who underwent oophorectomy and were provided estrogen therapy experienced significant attenuation of the risk for osteoporosis compared with those who were not treated with estrogen. The course of other conditions such as diabetes and hyperlipidemia was, however, not altered by estrogen.

The authors believe that their study has widespread public health implications because the practice of preventive bilateral oophorectomy in women with an average risk of ovarian cancer continues despite contradictory guidelines by several professional societies.

Reference

Rocca WA, Gazzuola-Rocca L, Smith CY, et al. Accelerated accumulation of multimorbidity after bilateral oophorectomy: a population-based cohort study [published online September 29, 2016]. Mayo Clin Proc. doi: http://dx.doi.org/10.1016/j.mayocp.2016.08.002.