A large-scale European study has found that the risk of ovarian cancer is cut almost in half for women who take birth control pills for a decade or more.
The study, published this week in the British Journal of Cancer, followed 327,396 women participating in the European Prospective Investigation into Cancer and Nutrition. Over a period of nine years, researchers found that 59 percent reported taking oral contraceptives at some point in their life. Half of those took the pill for less than five years. Follow-up revealed 878 cases of ovarian cancer.
The risk of ovarian cancer among ever-users of the Pill was 15 percent; while women who had taken the Pill for a decade or more had a reduced risk of 45 percent.
This study is consistent with previous research from Harvard Medical School, which has found that the risk of ovarian cancer decreases with increased duration of oral contraceptive use. During that analysis, there was a 10 to 12 percent decrease after one year of taking the Pill, and an approximate 50 percent decrease after five years of use.
This could be a significant development for women who have a family history of ovarian cancer. And with the advent of genetic testing, could also be helpful for women who may not have a family history but find themselves at higher risk.
The downside to long-term use of oral contraceptives is the increased risk of both breast and cervical cancers. Both cancers have a dependence on naturally occurring sex hormones—such as the estrogen and progesterone in the Pill—for their development and growth. So women who have a family history of either of those cancers want to be very careful about long-term use of oral contraceptives.
Facts on Ovarian Cancer
According to the American Cancer Society, every year almost 22,000 American women are diagnosed with ovarian cancer and more than 15,000 die from the disease. Approximately 90 percent of women who get ovarian cancer are over the age of 40, with the greatest number of ovarian cancers occurring in women aged 60 years or older.
Currently the CA125 blood test is the only blood test that can detect ovarian cancer. Because ovarian cancer is relatively rare and the benefits of early detection unclear, the U.S. Preventive Services Task Force, does not recommend that women be regularly screened for ovarian cancer. For women who have a personal or family history of gynecological cancer, having annual or biennial CA-125 testing done, for comparative analysis, is a suggested option.
While prevention is virtually impossible, you may be able to lower your chances of getting ovarian cancer by having one or more children, using birth control pills for more than five years, having a tubal ligation, both ovaries removed, or a hysterectomy.