Women who have their healthy ovaries removed when they have a hysterectomy face a higher risk of death, including death from coronary heart disease and lung cancer, than women who keep their ovaries, according to new research.
The finding, from a study published in the May issue of the journal Obstetrics & Gynecology, challenges conventional wisdom that removing ovaries along with the uterus offers the best chance for long-time survival.
Doctors have recommended for decades that women who get a hysterectomy consider having both ovaries removed—a surgical procedure called a bilateral oophorectomy—to prevent ovarian cancer later in life. Ovarian cancer is rare, accounting for about 3 percent of all cancers and 1 percent of deaths in women. But it is difficult to detect and treat, so many women opt to have their ovaries taken out.
Of the 600,000 women in the United States who get a hysterectomy every year, about 300,000 also have their ovaries removed— about 50 percent of those ages 40 to 44 and 78 percent of those ages 45 to 64.
But the study authors said routine removal is often not a good choice. Though the risk of ovarian and breast cancer declined after ovary removal, the risk of heart disease and stroke for women under 50 nearly doubled and risk of death overall before age 50 rose by 40 percent.
"For the last 35 years, most doctors have been routinely advising women undergoing hysterectomy to have their ovaries removed to prevent ovarian cancer," said lead author Dr. William Parker, who is on the adjunct faculty at the John Wayne Cancer Institute at St. John's Health Center in Santa Monica, Calif. "We believe that such an automatic recommendation is no longer warranted."
Removing the ovaries did not appear to provide an overall survival benefit for any age group of women, in large part because heart disease, stroke and lung cancer each is far more common than ovarian cancer.
Among women who had never used estrogen replacement therapy, the study also found that those who were younger than 50 when their ovaries were removed had a significantly greater risk of death from coronary heart disease, stroke and any cause than did older women.
Before menopause, women's ovaries are still producing estrogen and other hormones that have a protective effect on the heart, bones and blood vessels, said Dr. Bert Scoccia, professor and director in the division of reproductive endocrinology and infertility at the University of Illinois College of Medicine.
"My hope is that this study will change the way we practice medicine, especially in women before menopause," Scoccia said. "It makes sense to leave the ovaries if there are no risk factors or pathology at the time of surgery, especially in young women since those are the ones who seem to be most affected."
The study mined data from the national Nurses' Health Study, which has analyzed the health of 122,700 female registered nurses ages 30 to 55 since 1976. Over the past 24 years, 16,345 women in the study had a hysterectomy and their ovaries removed, and 13,035 women had a hysterectomy and kept their ovaries.
An international team led by Parker and researchers from Harvard Medical School analyzed incidence rates and deaths from coronary heart disease, stroke, breast cancer, ovarian cancer, lung cancer, colorectal cancer, total cancers, hip fracture and pulmonary embolism as well as death from all causes.
Study subjects were divided into three age groups. The study included pre- and postmenopausal women, some of whom were taking estrogen replacement therapy. None of the women had cancer at the time of hysterectomy.
Given their findings, the study authors urged women to talk to their physicians about their best options.
"Certainly, women with a strong family history of ovarian cancer, or women who know they carry the BRCA1 or BRCA2 gene mutations that greatly increase their risk of ovarian and breast cancer, should strongly consider having their ovaries removed," Parker said.
But in the case of women with a strong family history of heart disease or stroke, "maybe keeping your ovaries makes sense," Parker said.
Dr. Emmet Hirsch, director of obstetrics and gynecology at the Chicago area's NorthShore University HealthSystem, found the study findings convincing.
"I think it will and should change [medical] practice," Hirsch said. "We removed the ovaries because we were concerned about ovarian cancer, and it certainly does reduce the risk of ovarian cancer by a large degree. But the study showed that there are other factors, known and unknown, that affect quality of life and survival."