The Pill and Cancer Risks

Ovarian cancer risks reduced with the use of oral contraceptives

(RxWiki News) Women who carry mutations in the BRCA genes have higher risks for both breast and ovarian cancer. One way to reduce these risks is to have both their ovaries and breasts surgically removed. A new analysis looked at another possible way — birth control pills.

Oral contraceptives (birth control pills) lowered the risk for ovarian cancer among BRCA carriers and did not increase the risks for breast cancer, according to the new review.

One gynecological cancer expert told dailyRx News that these findings may offer high-risk women new alternatives to surgery.

"Talk to your doctor about ways to lower cancer risks."

Patricia G. Moorman, PhD, a researcher at Duke Cancer Institute in Durham, North Carolina, and colleagues conducted this meta-analysis of previous studies to evaluate links between oral contraceptive use and breast and ovarian cancer among women with BRCA1 or BRCA2 mutations or a family history of these diseases.

The researchers combed through nearly 6,500 studies to identify six studies that examined risks of ovarian cancer and eight studies looking at breast cancer risks among BRCA carriers.

The researchers also analyzed four studies looking at ovarian cancer risks and three studies evaluating breast cancer risks among women with a family history of the diseases.

In the study’s background, the authors pointed out that the lifetime risk for ovarian cancer in the general population is 1.4 percent. In contrast, the risk of developing ovarian cancer by age 70 years is estimated at 39 percent for BRCA1 carriers and 11 percent for BRCA2 carriers.

Previous studies have found that oral contraceptives did in fact reduce the risk of ovarian cancer in women with genetic risks for ovarian cancer.

However, oral contraceptive use is known to increase a woman’s risk of breast cancer and blood clots.

“Clinicians are often faced with the dilemma of how best to counsel BRCA mutation carriers regarding use of oral contraceptive pills (OCP). On the one hand, we know that OCPs may decrease the patient’s risk of ovarian cancer, but on the other hand, we are concerned about increasing her risk of breast cancer,” Iris Romero, MD, assistant professor of obstetrics/gynecology at the University of Chicago, told dailyRx News.

After analyzing the previous studies, Dr. Moorman and colleagues discovered that oral contraceptive use decreased ovarian cancer risks by 42 percent in women with BRCA gene mutations.

Breast cancer risks were elevated by 21 percent among BCRA carriers who took birth control pills, the study found, but this association did not reach statistical significance, according to the authors.

“The meta-analysis confirms that, like the general population, BRCA mutation carriers who use OCPs have a significant reduction in risk of ovarian cancer. Perhaps more importantly, the authors report that BRCA mutations carriers who use OCPs did not have a statistically significant increase in breast cancer risk,” Dr. Romero explained.

“Based on this meta-analysis,” Dr. Romero continued, “clinicians and patients should feel comfortable with BRCA mutation carriers using OCPs. In fact, when considering all contraceptive options, OCPs would be the best choice for these patients because of the pill’s proven ovarian cancer protective effect.”

Dr. Romero went on to say, “Even if a patient does not need contraception, if she is not ready for a prophylactic bilateral salpingoopherectomy [surgical removal of both ovaries] for ovarian cancer prevention, she could consider using OCPs to reduce her risk of ovarian cancer, and based on these results, she would not be increasing her risk of breast cancer,” Dr. Romero said.

This study was published October 21 in the Journal of Clinical Oncology.

The research was supported by the Agency for Healthcare Research and Quality, the Centers for Disease Control and Prevention and the US Department of Health and Human Services.

No conflicts of interest were declared.

Review Date: 
October 21, 2013