Scientists say removing ovaries during a hysterectomy could increase a woman’s risk for heart disease, cancer, and premature death.
A 10-year study, the largest of its kind, compared women who were treated for a benign disease who had both ovaries removed with those who had one or none removed. Researchers looked at 113,679 cases of women aged 35-45 from April 2004 to March 2014. A third of the patients studied had both ovaries removed.
“…The removal of a metabolically active organ such as the ovary may have harmful effects in the long term.”
Women who had one or no ovaries removed were less likely to develop ischemic heart disease (coronary artery disease) or cancer after hysterectomy than those who had both (bilateral) ovaries removed. Further, fewer women who kept one or both ovaries compared to those who had both removed died within the duration of the study—0.6 percent compared to 1.01 percent.
Although removal of both ovaries protects against subsequent development of ovarian cancer, researchers believe premenopausal women should be advised that this benefit comes at the cost of an increased risk of cardiovascular disease and of other more prevalent cancers and higher overall mortality.
“The combination of biological plausibility and the massive ‘effect size’ make a compelling case that women can be advised that their risk of ovarian cancer is greatly reduced by surgical removal of both ovaries,” says Richard Lilford, professor of obstetrics and gynecology at the University of Warwick Medical School.
“However, the lifetime risk of developing ovarian cancer is one in 52 in the UK, and the removal of a metabolically active organ such as the ovary may have harmful effects in the longterm.
“If so, these long-term disadvantages (combined with the unpleasant shorter term effects of acute estrogen deprivation) must be offset against the benefit conferred by protection from ovarian cancer.”
The researchers used a national database of hospital admissions which they linked to the national register of deaths. Unlike a previous, smaller Nurses’ Health Study, the new research was conducted on a countrywide basis rather than in a sample, and examined associations between operation type and subsequent hospital admissions, as well as mortality.
Forty percent of women with no specific risk factors for reproductive cancer had their ovaries removed during abdominal hysterectomy in the 35-45 age group.
“This might be a higher proportion than would be expected among women who were fully aware of the worse health outcomes with bilateral removal that we’ve reported,” Lilford says. “In that case, 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.”
The study also pointed to a small decline in the number of hysterectomies performed. Nearly 9,000 women had a hysterectomy for a benign condition in the target age range in 2014, compared to almost 13,000 in 2004-05.
The researchers acknowledge the data available wasn’t as detailed as they would have liked, in particular there was no information on the use of hormone replacement therapy—but they plan to re-examine the data at a later date to examine trends over the long term.
Source: University of Warwick