That mixture of fear and faith has helped fuel the backlash against new recommendations from the U.S. Preventive Services Task Force, says Fran Visco, president of the National Breast Cancer Coalition. The independent panel suggested last week that doctors stop routinely performing mammograms on most women under 50 and instead let women make up their own minds about the risks and benefits of the screening tests.

For two decades, Visco says, cancer groups have oversold and oversimplified the benefits of early detection to get women to follow their advice about breast screening. Many women now see mammograms as completely positive, with no risks, and are unwilling to give them up.

"When we give public health messages, we better be damn sure that they are rooted in a high level of evidence," Visco says. "Taking back our words when we finally have the right evidence is virtually impossible."

The American Cancer Society's Robert Smith, who supports mammograms for younger women, says public health messages have to be simple. "To say 'screening saves lives' is a shortcut," he says. Screening is "the pathway to a treatment that reduces your risk of death."

The decision to have a mammogram is actually more complex than many realize, Schwartz says. In addition to causing "false alarms," in which suspicious results later prove to be benign, mammograms also lead some women to undergo unnecessary treatments for tumors that aren't actually life-threatening, she says.

"People may have unrealistic expectations about what mammography can and can't do," says the American College of Radiology's Carol Lee, who promotes routine mammograms for women in their 40s. "But it's the best test we have to offer, as imperfect as it is."

Schwartz says she grapples with the question of screening herself. And she understands why many young women want to continue having regular mammograms.

But she says doctors need to do a better job helping women understand the big picture: "People should be able to discuss these things and make the decision that's right for you."

Enlarge By H. Darr Beiser, USA TODAY