October 2008

Removal of healthy ovaries as cancer prevention unproven

Half million procedures performed each year despite lack of scientific evidence

Although only one out of 119 reviewed studies suggested that prophylactic oophorectomy might be beneficial, some half million of the procedures are performed yearly. About 454,000 women in the United States underwent this type of operation in 2004, according to the Center for Disease Control.

While removal of healthy ovaries as a preventive measure is supposed to lower the risk of developing ovarian cancer later in life, the evidence is far from conclusive.

"Prophylactic oophorectomy is performed across the world on the basis of very limited evidence," said Leonardo Orozco, MD, an attending OB/GYN at Women's Hospital San José in Costa Rica. "Questioning this practice is a crucial step in advancing our ability to make decisions that may ultimately improve the health and well-being of women."

Dr. Orozco and colleagues reviewed 119 studies related to the issue of prophylactic oophorectomy. "After our search, we were able to find only one clinical control trial of low-quality that has been used to justify such a high number of prophylactic oophorectomies every year," Orozco said.

That single study included 362 women, aged 45 to 55 when it began. Of those, 217 underwent hysterectomy alone and 106 underwent hysterectomy plus oophorectomy. The study looked at the average changes in psychological well-being and sexuality, both before and one year following the surgery.

"For me, the most important result of this research was to raise the awareness that, as physicians, we must always question why we are performing a specific procedure. We cannot always rely on training, as there are 'habitual' procedures that we undertake, which may not be the best evidence-based decision," Orozco added.

The review appeared in The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research.

Orozco noted that it is important to consider the long-term implications of ovary removal, some of which remain unclear.

For example, even after menopause, the ovaries produce significant amounts of certain hormones that other tissues convert to estrogen. "Therefore," he said, "there could be underlying advantages of ovarian function … that may mean that removal of the ovaries has clinically significant consequences."

"The conclusions of this review are limited by the lack of data," Orozco pointed out. "However, it demonstrated that more research of higher methodological quality is needed in order to justify an intervention that we still don't know is beneficial or harmful."

SOURCE: "Hysterectomy versus hysterectomy plus oophorectomy for premenopausal women," by Orozco LJ, et al. The Cochrane Database of Systematic Reviews, 2008, Issue 3.