(Oct. 21) -- After years of advocating for the importance of cancer screening, the American Cancer Society says the benefits of it in detecting prostate and breast cancer have been "exaggerated."

“We don’t want people to panic,” Dr. Otis Brawley, chief medical officer of the cancer society, told The New York Times. “But I’m admitting that American medicine has overpromised when it comes to screening. The advantages to screening have been exaggerated.”

The group plans to advise people on its Web site that screening for breast, prostate and other cancers comes with the risk of both overtreating smaller cancers and missing potentially fatal cancers.

Though there have been several studies regarding problems with prostate screening -- it's not recommended for all men -- there's been a lot less debate about mammograms to detect breast cancer, the Times said.

“The issue here is, as we look at cancer medicine over the last 35 or 40 years, we have always worked to treat cancer or to find cancer early,” Brawley told the paper. “And we never sat back and actually thought, ‘Are we treating the cancers that need to be treated?’ ”

Still, researchers say screening shouldn't stop completely, but that people need to be aware of the risks and benefits of it.

For more on this story, go to The New York Times.