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.
But recent widely publicized developments have challenged that notion, which has been an article of faith in American medicine.
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.
A national story published in November reported that the American Cancer Society (ACS), one of the staunchest defenders of cancer testing, was planning to scale back its support of mass breast and prostate cancer screenings. Otis Brawley, the group’s chief medical officer, said that “American medicine has overpromised” and that “the advantages to screening have been exaggerated.”
One impetus for Brawley’s statements—which also ignited a furor and forced the ACS to quickly reiterate its support of mammography beginning at 40—was an analysis published Oct. 21 in the Journal of the American Medical Association.
Researchers from the University of California, San Francisco (UCSF), and the University of Texas Health Science Center in San Antonio reported that 20 years of screening for breast and prostate cancer, which account for more than 25 percent of cancers diagnosed annually in the United States, have not significantly reduced the death rate from either.
Instead, the authors wrote, widespread screening has increased the detection and treatment of small, slow-growing tumors that may never cause harm—and in some cases may even disappear—while failing to detect aggressive tumors sometimes known as “interval” cancers because they arise between screenings and grow swiftly.
For every breast cancer death averted in women ages 50 to 70, 838 women must undergo screening for six years, “generating thousands of screens, hundreds of biopsies and many cancers treated as if they were life threatening when they are not,” wrote the team headed by breast cancer specialist Laura Esserman, a professor of surgery and radiology at UCSF.
Baltimore area internist Mary Newman says she thinks many patients are not aware of the potential harms of screening: the small risk posed by repeated radiation, the stress caused by a false positive and the risk of overtreating a small, slow-growing cancer that may never cause problems.
So what advice do cancer experts offer Americans over 50 wrestling with the question of when—or whether—to be screened? How risky is it for those without risk factors—such as a family history of breast or prostate cancer—to forgo annual screening?