'Tube-Tying' Procedure Reduces Risk of Ovarian Cancer
May 10, 2001 -- Having the well-documented mutations in the breast cancer genes called BRCA1 and BRCA2 not only increases a woman's risk of developing breast cancer but also increases her risk of developing ovarian cancer.
And when some women learn they have the BRCA1 mutations -- which can increase the risk of ovarian cancer by 40% -- they may resort to extreme measures to protect themselves, such as having their breasts or ovaries removed before they develop cancer.
But Steven A. Narod, MD, a cancer prevention expert at the University of Toronto, says that the risk of ovarian cancer can be lowered by 60% by simply cutting or 'tying-off' a woman's fallopian tubes, the passageways that carry an egg from the ovary to the uterus. This common birth control procedure is called tubal ligation.
Narod, a professor at Sunnybrook and Women's College Hospital, tells WebMD that some women may prefer this sterilization procedure because "it doesn't have any side effects." Women who have their ovaries removed, a procedure called an oophorectomy, will immediately experience menopause symptoms.
Those symptoms, which can include hot flashes, night sweats, sleep disturbances, mood swings, vaginal dryness, and an increased risk of osteoporosis, can be effectively treated with hormone replacement therapy -- but some women worry that estrogen replacement may increase the risk for breast cancer. Because the birth control procedure leaves the ovaries in place, he says, "no hormone replacement is required." He adds, though, that birth control pills themselves can reduce the risk of ovarian cancer by about 50% to 60% in women with mutations in BRCA.
Narod studied more than 450 women from Canada, the United States, and the United Kingdom. All of the women had either BRCA1 mutations or BRCA2 mutations; women with BRCA2 mutations have an increased ovarian cancer risk of about 25%. Invasive ovarian cancer was diagnosed in 232 of the women. These women were compared with 232 women who carried the gene mutations but had not developed ovarian cancer. The women were matched for age, country of residence, and mutation type. He reports his findings in the May 12 issue of The Lancet.
"Only 18% of the women with ovarian cancer had tubal ligations compared to 35% of the healthy controls," he says. Narod says tubal ligation cuts ovarian cancer risk by 60%. The risk reduction is even greater -- 72% -- if the women used birth control pills, he says. He did not find a similar association among women with BRCA2 mutations but says that only one in four women had BRCA2 mutations so the "sample size was so small that it would be difficult to detect a benefit."
David Mutch, MD, a professor at Washington University School of Medicine, tells WebMD that other studies have demonstrated that "all women who have tubal ligations have a decreased risk for ovarian cancer regardless of genetic background, so it doesn't surprise me that women with BRCA1 [mutations] could significantly reduce their ovarian cancer risk with surgery."