It is a staple of women's health advice and visits to the OB/GYN: the monthly breast self-exam to check for lumps or other changes that might signal breast cancer. However, a review of recent studies says there is no evidence that self-exams actually reduce breast cancer deaths. (July 2008) Instead, the practice may be doing more harm than good, since it led to almost twice as many biopsies that turned up no cancer in women who performed the self-exams, compared to women who did not do the exams.

"At present, screening by breast self-examination or physical examination [by a trained health worker] cannot be recommended," Jan Peter Kosters, Ph.D., and Peter Gotzsche, Ph.D., of the Nordic Cochrane Centre, conclude in the review.

The review is an updated version of a 2003 review of studies, which came to a similar conclusion.

Debbie Saslow, Ph.D., director of breast and gynecologic cancers for the American Cancer Society, said the assoication revised its guidelines and stopped recommending monthly breast self-exams five years ago in light of the evidence that had emerged. The guidelines now call the monthly exam "an option" for women beginning in their 20s.

"We are advising that women should be aware of what is normal for how their breasts looked and felt, and to promptly report any changes to their health care provider," Saslow said. "Women who want to should keep doing breast self-exam, and women who don't want to, don't need to."