The pill doesn't boost breast cancer death risk

By Anne Harding

NEW YORK (Reuters Health) - Survival is no better or no worse among breast cancer patients who have used the birth control pill, according to a report in the journal Obstetrics and Gynecology.

The findings are "broadly reassuring," Dr. Herbert R. Peterson of the University of North Carolina at Chapel Hill, one of the study's authors, told Reuters Health. "There just doesn't appear to be any concern about women using the pill at younger ages from the standpoint of breast cancer."

Concerns had been raised about oral contraceptives and breast cancer by an analysis of 54 studies, published in 1996, which found an increased risk of the disease among women currently on the pill, Peterson noted.

Researchers hypothesized that women on birth control might have more consistent access to healthcare, and thus be more likely to have breast cancers detected early, which would mean they would have a corresponding reduced risk of being diagnosed with advanced disease.

To investigate, Peterson and his team looked at use of oral contraceptives and the risk of dying from breast cancer among 4,292 women aged 20 to 54 who had been diagnosed with the disease.

The researchers found no increased risk of death associated with use of the pill, duration of use, or any specific oral contraceptive formulation. Women currently taking oral contraceptives were actually at 10-percent lower risk of dying from the disease, but this finding may have been due to chance.

Another large study conducted in 2002 found no increased risk of breast cancer among women currently on the pill, Peterson pointed out.

"There are now dozens and dozens of studies looking at the pill and breast cancer risk, and when you pull them all together they're broadly reassuring, both in terms of the risk and in terms of the risk of mortality," he said in an interview.

The one unanswered question remains the safety of the pill for women approaching menopause, given the increased risk of breast cancer recently identified for menopausal women taking hormone replacement therapy, Peterson said.

"For healthy women over 40 who don't smoke, oral contraceptives continue to be an option for contraception, and for many a good option," he added. Nevertheless, Peterson said, more research needs to be done to confirm that the pill is safe for older women.

SOURCE: Obstetrics & Gynecology, October 2007.