No Link Found Between Pill, Breast Cancer

A large new study found that the pill does not raise the risk of breast cancer.

Experts from the National Institute of Child Health and Human Development found that risk does not rise even among women who started taking oral contraceptives early or who have close relatives with breast cancer.

In fact, oral contraceptives reduce women's risk for endometrial and ovarian cancers, according to the study, which appears in Thursday's issue of the New England Journal of Medicine.

Researchers studied more than 9,200 black and white women ages 35 to 64. living in Atlanta, Detroit, Philadelphia, Los Angeles and Seattle. Roughly half of the study participants had recently been diagnosed with breast cancer, while the other half did not have a diagnosis of breast cancer. The women were interviewed in person and asked a series of questions about their use of oral contraceptives and other hormones as well as their reproductive, health and family issues.

They found that the women who never took the pill were about as likely to have breast cancer as those who were taking it or who had taken it.

"These results are good news," said lead author Polly Marchbanks. "For women 35 to 64 years old, this study provides reassurance that oral contraceptives do not increase the risk of breast cancer."

An outside expert said the findings should reassure most women on the pill. But she said she still has some reservations about women with a strong family history of breast cancer.

About 80 percent of U.S. women born since 1945 have used oral contraceptives. There has been some concern in the past about the possible effect of oral contraceptive use on breast cancer risk.

In fact, a 1996 formal review of 54 smaller studies conducted over the past 25 years found a slightly increased risk of breast cancer in women who were current or recent users of oral contraceptives. Other previous studies did not find an increased risk of breast cancer among oral contraceptive users.

"Large numbers of women who took oral contraceptives during their reproductive years are now reaching the ages of greatest breast cancer risk," said Robert Spirtas, chief of NICHD's Contraception and Reproductive Health Branch and one of the authors of the study. "We conducted this study to resolve the long-standing concern that oral contraceptive use might be associated with an increased risk of breast cancer in later life. Our study provides scientific evidence that there is no such association."

While the researchers concluded that the benefits of taking the pill outweigh the risks, they caution that, while rare, oral contraceptives are associated with an increased risk of other conditions, including blood clots, stroke, liver cancer, heart attack in women over 35 who smoke, and cervical cancer in women infected with the human papillomavirus.