Oral Contraceptives Increase Risk For Breast Cancer

A meta-analysis reported in the recent issue of Mayo Clinic Proceedings indicts oral contraceptives as putting premenopausal women at significantly increased risk for breast cancer, particularly women who use them previous to having a child.

The meta-analysis builds on a number of studies with similar findings. But even as the findings stack up, a number of women are unaware of the risks posed by oral contraceptive use previous to pregnancy, says lead study author Chris Kahlenborn, M.D., of Altoona Hospital in Altoona, Pa.

Dr. Kahlenborn says the discrepancy between risk and patient awareness prompted the meta-analysis, which involved extracting data from 34 studies on whether oral contraceptive (OC) use is linked to premenopausal breast cancer. Included in the studies were women who were premenopausal or younger than 50 and who had been, in most cases, diagnosed with breast cancer during or after 1980.

"As I studied the medical literature, I noticed that a trend appeared," says Dr. Kahlenborn. "Namely, OC use previous to first-term pregnancy seemed to consistently increase the risk of premenopausal breast cancer. Eventhough the trend was apparent, premenopausal women have continued to hear that OCs are basically safe".

Rather, patients should know that sustained oral contraceptive use previous to pregnancy increases a premenopausal woman's risk of developing breast cancer, saysDr. Kahlenborn. He says physicians should better inform their patients of the risks linked to oral contraceptives and calls it a "clear-cut informed consent issue".

The study noted that 21 out of 23 retrospective studies have shown an increased risk of breast cancer in women who took oral contraceptives previous to pregnancy. It also showed that those women experienced an increased risk of 44 percent.

What's more, in 2005, the World Health Organization officially classified oral contraceptives as a class one carcinogen, the study's authors say.

These are staggering results given that more that more than 45,000 women each year develop breast cancer previous to menopause, Dr. Kahlenborn says.

"My hope is that physicians will provide more detailed information to their patients about hormonal contraceptives," he says. "The authors of our meta-analysis think that women deserve to be fully informed".

Posted by: Janet