Bilateral Ovarian Removal Associated With Increased All-Cause Mortality

Woman who undergo bilateral removal of ovaries at the time of hysterectomy have higher risks of all-cause mortality afterward, according to a new study. Consistent with this finding, those women also had higher rates of hospital admission for ischemic heart disease, among other outcomes.

“Strong arguments exist to remove both ovaries at the time of hysterectomy in women who have reproductive cancers or who have a high risk of developing cancers,” wrote study authors led by Jemma Mytton, of University Hospitals Birmingham in the United Kingdom. “However, the lifetime risk of developing ovarian cancer is 1 in 52 in the United Kingdom, and the removal of a metabolically active organ such as the ovary may have harmful effects in the long term.”

The new study examined whether those potential effects have an impact on overall survival and other outcomes, using national databases of hospital admissions and deaths. In total, it included 113,679 patients aged 35 to 45 who underwent hysterectomy for benign conditions between April 2004 and March 2014. Of those, 37,098 patients (32.6%) underwent bilateral ovary removal. Results of the analysis were published online ahead of print last week in the British Medical Journal.

In the ovarian conservation group, the rate of hospital admission for ischemic heart disease was 1.60%, compared with 2.02% in the bilateral removal group, yielding an adjusted hazard ratio (HR) of 0.85 (95% CI, 0.77–0.93; P < .001). The median time to ischemic events was 56 months in the ovarian conservation patients, significantly longer than the 51 months in the bilateral removal group (P < .001).

Cancer admissions were also lower in the conservation group (2.80%) than in the bilateral removal group (3.49%), with an adjusted HR of 0.83 (95% CI, 0.78–0.89; P < .001).

The all-cause mortality rate in the ovarian conservation group was 0.60%, compared with 1.01% in the bilateral removal patients, for an adjusted HR of 0.64 (95% CI, 0.55–0.73; P < .001). More deaths in the conservation group (13.4%) occurred within the first 12 months following hysterectomy than in the bilateral removal group (17.3%), though this did not reach significance (P = .12). When the researchers excluded ovarian cancer deaths from this analysis, the adjusted HR was even more strongly in favor of conservation, at 0.60 (95% CI, 0.52–0.69; P < .01).

The authors wrote that these findings align with the theory that a drop in endogenous estrogen concentrations could increase heart disease risk. “We might expect the proportion of women who select bilateral ovarian removal to decline as the health risks that must be traded for a reduced incidence of ovarian cancer come into sharper focus,” they wrote.