The following article gives an overview of a research study conducted by Dr. Parker and his colleagues to look at the long-term survival of women who had hysterectomies.
Women often have their healthy ovaries removed when they are having a hysterectomy in order to prevent ovarian cancer from developing in the future. About 50 percent of women who have a hysterectomy between ages 40-44 have their ovaries removed, and 78 percent of women between ages 45-64 undergoing a hysterectomy have their ovaries removed. All together, about 300,000 American women have their healthy ovaries removed every year.
If the ovaries are removed before menopause, a sudden decrease in the hormones made by the ovaries, including estrogen, testosterone and androstenedione, results. Even after a woman enters menopause, her ovaries continue to make considerable amounts of testosterone and androstenedione, which are then changed into estrogen by other cells in the body.
Some studies have already shown that women who keep their ovaries have a lower risk of heart disease. While ovarian cancer accounts for 14,700 deaths per year in the U.S., heart disease causes 326,900 deaths, and stroke causes 86,900 deaths each year. If a woman is not at high risk for ovarian cancer, keeping their ovaries might benefit her overall health and survival.
We designed a study to see whether it was better for women who needed a hysterectomy to keep their ovaries or have them removed during the surgery to remove the uterus.
We used the database from the Nurses Health Study, which included 122,700 registered nurses in 1976 when it began. Over the past 28 years, 29,380 of the women had a hysterectomy for benign (noncancerous) reproductive diseases. Of these women, 16,345 had a hysterectomy and removal of their ovaries (oophorectomy), and 13,035 had a hysterectomy with ovarian conservation (ovaries kept).
We considered what diseases and conditions the women died from in the years after their surgery. The results showed that women who had their ovaries removed had a higher risk of death from any cause, primarily from heart disease, lung cancer and colorectal cancer. Removing the ovaries at any age did not improve life-span for this group of women.
During the 28 years of follow-up, 44 of the 13,305 women (0.9 percent) who kept their ovaries died from ovarian cancer. While breast cancer and ovarian cancer were less frequent in women who had their ovaries removed, the overall risk of death from all types of cancer was higher among women who had their ovaries removed. There was 25 percent less breast cancer in women who had their ovaries removed, but no difference in death from breast cancer (with early detection and treatment, most women — about 75 percent — survive breast cancer).
When we considered just the women who had their ovaries removed before age 50 and who never used estrogen therapy after surgery, we found that they had a higher risk of death from any cause.
For the past 35 years, doctors have recommended that women who needed a hysterectomy also consider having their ovaries removed in order to prevent the future development of ovarian cancer. Since ovarian cancer is difficult to detect and difficult to cure, most women having a hysterectomy chose to have their ovaries removed as well. Additionally, it now appears that the most aggressive form of ovarian cancer actually comes from the fallopian tubes and not the ovaries (see below).
Our study questions the routine removal of women’s ovaries by showing that heart disease, stroke and lung cancer are more common in women who have their ovaries removed. Furthermore, since heart disease, lung cancer and colorectal cancer are each much more common than ovarian cancer, more women who have their ovaries removed will die of these conditions than can be saved from getting ovarian cancer.
As is true with all medical decisions, it is important to discuss these issues with your doctor. People often make very different decisions based on the same medical information. Certainly, women with a strong family history of ovarian cancer, or women who know they have the genetic mutation (BRCA) that greatly increases their risk of ovarian and breast cancer, should strongly consider having their ovaries removed after childbearing.
It’s Not Ovarian Cancer!
Recently, researchers who have carefully examined the ovaries and tubes of women who are BRCA positive (and therefore at high risk of getting ovarian cancer) have made an astonishing discovery: they found that these women had precancerous cells ONLY in the fallopian tubes and NOT in the ovaries. Genetic studies of these cells showed the same mutations that are found in ovarian cancer. This means that this deadly form of ovarian cancer does not actually come from the ovary, and that the most aggressive ovarian cancers are, in fact, tubal cancers.
Following this discovery, removal of the fallopian tubes was proposed as an alternative to removal of the ovaries. This approach removes the source of aggressive cancers and conserves functioning ovaries. A recent study found that removal of the tubes did not affect the blood supply or function of the ovaries, so this appears to be a reasonable option. In November 2013, The Society of Gynecologic Oncologists published practice guidelines suggesting that for women at average risk for ovarian cancer, removal of the tubes should be considered (after completion of childbearing) at the time of hysterectomy, instead of tubal ligation, and also at the time of other pelvic surgery.
We now have a convergence of ideas: removal of the ovaries has adverse long-term health consequences for women and ovarian conservation should be encouraged; aggressive ovarian cancer appears to be tubal cancer and removing the fallopian tubes may prevent many deaths.
The full citation for this study is:
Parker W, Feskanich D, Broder M, Chang E, Shoupe D, Farquhar C, Berek J, Manson J. Long-Term Mortality Associated With Oophorectomy Compared With Ovarian Conservation in the Nurses’ Health Study. Obstet & Gynecol. 2013;121:709-716. Available online at http://www.ncbi.nlm.nih.gov/pubmed/23635669.