What You Must Know About Breast Cancer Screening Now

Robin Hall Guadagnini wasn’t supposed to have a mammogram the year she turned 41. She’d had one the year before, and her insurance covered routine mammograms only once every other year. But Guadagnini, a pension-plan administrator from Fayetteville, Arkansas, decided to pay out of her own pocket, even though she had no family history of the disease.

“I just felt it was important to stay on top of things and be proactive,” she says. Sure enough, the mammogram revealed a tumor in her right breast. “It was too small to be felt,” Guadagnini says. “As I like to say, by the grace of a mammogram my cancer was found.” Guadagnini had a lumpectomy and radiation, and has been cancer-free for seven years.

Guadagnini’s is the kind of tale that makes you want to be religious about getting mammograms. You’d have to be living on a media-free compound on a remote island not to have had the importance of early detection drummed into your head by celebrities, advocacy groups, and your own doctors. Slogans like the American Cancer Society’s “Mammography: The Chance of a Lifetime!” have become as ubiquitous as the pink ribbons on every lapel in the elevator. The message was clear: get a mammogram every year once you turn 40, as a matter of course.

It’s no wonder, then, that so many women felt whipsawed and angered by the screening guidelines released last November by the U.S. Preventive Services Task Force. The independent panel came out against routine screening for women in their 40s, suggesting that women get routine mammograms later and less often. “I felt complete shock and dismay,” Guadagnini says. “My reaction was, I can’t believe this
is what they’re telling people. It’s a step backward.”

Most of us know women like Guadagnini, whose cancer was caught early and treated, as well as women who did not get screened and whose disease was found too late to save their lives. Screening early and often seems like a no-brainer. But as scientists are coming to understand—and the new guidelines were meant to reflect—screening has a significant downside. Mammograms yield many suspicious results, which often lead to anxiety and invasive follow-up tests that reveal that no cancer is present. More troubling, mammograms also detect cancerous growths that may never pose a threat to your health; the aggressive treatment of these growths, however, can harm your health far more than if the growth were left alone.

This phenomenon of overdiagnosis is nothing new to cancer researchers. “But we’re only now getting a sense of the magnitude of the problem,” says H. Gilbert Welch, MD, professor of medicine at the Dartmouth Institute for Health Policy and Clinical Practice in Hanover, New Hampshire. Studies suggest that as many as one in three tumors detected by a mammogram are treated as if they’re life threaten­ing when they are not—and that’s not including the thousands of false positives. Stories like Guadagnini’s are compelling, of course. But, according to Dr. Welch, many women treated aggressively for cancer may not have dodged a bullet at all. A woman who sees herself as a survivor and having had her life saved may well, in fact, have been overdiagnosed, he says.