By Kerry Grens
NEW YORK (Reuters Health) - Though it's been common practice during hysterectomy to remove a woman's ovaries, a new study suggests there may be benefits in leaving them intact.
Researchers found that women's risk of ovarian cancer diminished when their ovaries were removed, but their risks of dying from other, more common causes rose.
Based on the results, "it looks like, if given a choice, you should keep your ovaries," said Leslie Bernstein, a professor at City of Hope cancer center, who was not involved in the study.
Tens of thousands of women each year have their ovaries taken out during a hysterectomy, the surgical removal of the uterus.
The idea is to prevent ovarian cancer, and the rationale has been that if the woman is finished having children, her ovaries are of no use and might as well come out while the surgeon is in there.
"If you ask women what they are afraid of, after breast cancer it is ovarian cancer," said Bernstein. "We do well with (treating) breast cancer; we do not with ovarian cancer."
About 22,000 women are diagnosed with ovarian cancer each year in the U.S. and 14,000 die from the disease annually.
Women with certain gene mutations or a strong family history of ovarian cancer are at heightened risk for the disease.
But about 98 percent of the women getting their ovaries removed during hysterectomy are not in that high-risk category, according to Dr. William Parker, the lead author of the new study.
And there might be some utility to the ovaries, even past the childbearing years, said Parker, a gynecologist and clinical professor at the University of California, Los Angeles School of Medicine.
Although the production of hormones by the ovaries eventually shuts down following menopause, it is a slow decline, and studies have shown "there were benefits to having those hormones around," Parker said.
To see whether keeping one's ovaries is tied to survival, Parker and his colleagues looked to a large survey that has tracked the health and lifestyle of thousands of nurses for decades.
Of the roughly 30,000 women who underwent a hysterectomy, nearly 17,000 had both ovaries removed, while the rest kept their ovaries.
The researchers found that over the course of 28 years, 16.8 percent of those who had their ovaries removed died, compared to 13.3 percent of those with their ovaries.
The women's risk of dying from ovarian cancer was dramatically reduced if their ovaries were taken out - 44 women in the group with ovaries died, versus four in the group without ovaries.
But the women who had their ovaries taken out had a 13 percent greater risk of dying from all other causes, Parker's team reports in the medical journal Obstetrics & Gynecology.
Among those other causes, heart disease and other forms of cancer predominated. The group without ovaries had a 23 percent increased risk of dying from heart disease, a 29 percent greater chance of dying from lung cancer and a 49 percent higher risk of dying from colorectal cancer than the women who kept their ovaries.
For instance, nearly three percent - 481 women - in the group with their ovaries removed died from cardiovascular disease, while closer to two percent - 281 women - died in the group that kept their ovaries.
Parker said the trade-off for a lower risk of ovarian cancer is not worth losing the benefits linked with conserving the ovaries.
"Except for women who are at high risk for ovarian cancer with a known genetic mutation or a very strong family history...for everybody else, if you have your ovaries out you're actually more likely to die and more likely to die of the things that kill more women," Parker told Reuters Health.
"We focus on one disease to the exclusion of all these other diseases that are more likely to kill women," he said.
A previous study by Bernstein and her colleagues found that women were no more likely to die if they had their ovaries removed (see Reuters Health story of February 25, 2011 here: http://reut.rs/v8k3AW).
But Bernstein pointed out that her study compared women who had hysterectomies with ovary removal to women who did not have any surgery, whereas all of the women in this latest study had a hysterectomy.
Parker's study cannot determine why keeping the ovaries is tied to a better chance of living longer.
Bernstein said there is always the possibility that it's not the ovaries themselves, but other health factors related to the decision to have them removed.
"We don't know what led to a choice to have (both ovaries removed) when you have your hysterectomy or not. So there could be hidden issues related to health that we can't understand or control for," she said.
Parker said that for women without an elevated risk of ovarian cancer, it shouldn't be the default practice to take the ovaries out with the uterus, and women should discuss the decision with their physicians.
"In my practice I never take the ovaries out unless (patients) have a very compelling reason," he said.
SOURCE: http://bit.ly/ZRONjp Obstetrics & Gynecology, online March 6, 2013.