En español | For years the dominant view among patients and doctors about screening for breast and prostate cancer could be expressed in an equation: early detection + aggressive treatment = increased longevity.

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But recent widely publicized developments have challenged that notion, which has been an article of faith in American medicine.

Mammography screening should begin at age 50, instead of 40, say new recommendations. — Photo by Ben Edwards/Getty Images

The mammography recommendations published in November by the U.S. Preventive Services Task Force, an independent, federally appointed panel of experts, set off a storm of protests by some breast cancer activists and physician groups. Nearly all of the negative reaction has focused on the panel’s recommendation that women without risk factors undergo screening mammography beginning at age 50 instead of 40. The risks of mammograms before 50, the panel concluded, echoing the findings of previous groups as well as large new studies, outweigh the benefits of early detection.

The task force also recommended that women ages 50 to 74 without symptoms or risk factors such as a family history of breast cancer undergo mammography every other year rather than annually. It also advised doctors to stop teaching patients to perform breast self-exams, because there is no evidence they are effective.

Health reform critics immediately called the recommendations "rationing," which prompted federal officials to declare that screening guidelines for government health programs would remain unchanged.

Still, evidence that fewer screenings are needed is mounting.

Next: The case for fewer screenings. >>