More Mammograms May Mean More 'Harmles...(ee screening programs were started in fi...),Health

The regions included were the United Kingdom; Manitoba, Canada; New South Wales, Australia; Sweden; and parts of Norway.

They found an estimated overdiagnosis rate of 52 percent for all cancers, including in situ malignancies, which have not spread, and an overdiagnosis rate of 35 percent for invasive breast cancer. The study also detected a jump in incidence rates after the introduction of the screening programs.

An editorial accompanying publication of the study noted that overdiagnosis can cause women much trauma and alarm and that the choice to get a mammogram remains a personal one.

Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La., observed the situation as having pros and cons.

"The good news is we have affected survival dramatically, and we have affected the ability to diagnose cancers earlier so that most women don't have to remove their breast," Brooks said. "There is a trade-off."

More information

The U.S. National Women's Health Information Center has more on mammography.

SOURCES: Richard J. Bleicher, M.D., breast cancer surgeon, Fox Chase Cancer Center, Philadelphia; Jay Brooks, M.D., chairman, hematology/oncology, Ochsner Health Clinic, Baton Rouge, La.; July 9, 2009, BMJ, online