No Added Breast Cancer Risk Found in Pill Study
Women with a family history of breast cancer do not appear to increase their risk of developing the disease by taking birth control pills, according to a study released Tuesday.
Adding to the sometimes confusing array of research regarding the association between breast cancer and oral contraceptives, the study said that neither the length of time on the pill nor the length of its use before pregnancy seemed to have any bearing on the breast cancer risk among women whose mothers, sisters or daughters had suffered breast cancer.
Further, the researchers said, they also found no elevated risk of breast cancer in women using the pills who had a “second-degree” family history, that is, a grandmother or aunt who had developed the disease.
Women with a family history of breast cancer already have a well-established increased risk of developing the disease, but researchers found “very strong evidence” that taking the pill does not seem to add to the danger, according to Dr. Bruce Stadel, one of the study’s authors and an official in the Food and Drug Administration’s division of epidemiology and surveillance.
“The evidence is very substantial in that regard,” he said in an interview.
Pamela P. Murray, a research associate at the Uniformed Services University of the Health Sciences--the military’s medical school--agreed.
“Based on our findings, there appears to be no need to add family history of breast cancer to the list of contraindications for oral contraceptive use,” said Murray, the lead author of the study. Women who have already had cancer themselves are advised to avoid the pill.
About 13.2 million American women take oral contraceptives, which were introduced onto the U.S. market in 1960.
Breast cancer will strike one in 10 American women, according to the American Cancer Society. The organization has estimated that there were 135,000 new cases in 1988, and 42,300 deaths.
The new study, which was published in “Obstetrics and Gynecology,” the official journal of the American College of Obstetrics and Gynecology, lends additional credence to what many scientists have long believed--that most evidence indicates that taking birth control pills “has no appreciable effect on the lifetime risk of developing breast cancer,” Stadel said.
There have been some studies, however, that have shown a possible link between older, high-dose pills and the earlier onset of breast cancer in susceptible women, that is, women who were already prone to developing the disease for other reasons, he said.
Using data from the Cancer and Steroid Hormone Study of the Centers for Disease Control and the National Institute of Child Health and Human Development, the researchers evaluated the effect of birth control pills among 554 women between 20 and 54 who had been diagnosed as having breast cancer and who had a mother, sister or daughter who had suffered breast cancer. When they compared this group to 280 controls--women free of breast cancer but who had a similar first-degree family history of the disease--they found no evidence that oral contraceptive use, even over a long term, contributed to an increased risk of breast cancer.
