WEDNESDAY, July 16 (HealthDay News) -- Updated findings from an analysis of existing research continue to suggest that the oft-touted monthly breast self-exam may actually do more harm than good.

There is no evidence that the practice actually decreases deaths from breast cancer while it may actually double the number of unnecessary biopsies in women who do the exam compared with women who don't.

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

The current review, published in the most recent issue of The Cochrane Library, updates and corroborates information from a 2003 review of studies.

The American Cancer Society revised its guidelines five years ago based on emerging evidence and no longer recommends monthly breast self-exams. The monthly exam is now considered "an option" for women starting in their 20s.

The current review included two studies of almost 400,000 women in Russia and China. Women who did self-exams had 3,406 biopsies compared with only 1,856 biopsies in the group that did not do the exams. Differences in biopsy rates did not translate into differences in breast cancer mortality.

The China study found that rates of mastectomy and lumpectomy (or "breast-conserving" surgery) were similar regardless of whether women were doing self-exams or not.

As always, however, women who detect any change in their breast need to consult a doctor.

More information

Visit the National Cancer Institute for more on breast cancer.