Last updated: Mar 01, 2010
Anita Kunz

Robin Hall Guadagnini wasnt supposed to have a mammogram the year she turned 41. Shed 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.

Guadagninis is the kind of tale that makes you want to be religious about getting mammograms. Youd 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 Societys “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.

Its 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 cant believe this
is what theyre telling people. Its 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 were 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 theyre life threaten­ing when they are not—and thats not including the thousands of false positives. Stories like Guadagninis 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.

Positively scary
Alex Hafts (not her real name) story is far more common than Guadagninis. The New York City mother of two had a baseline mammogram prior to having in vitro fertilization when she was 35, to make sure there were no cancers that might be fueled by the hormones. She, too, was told that the screening had turned up a suspicious mass. Terrified, she had a core needle biopsy, in which a device that sounded like a staple gun was used to remove a chunk of tissue.

“The weekend I spent waiting for the results—thinking I may never have children—was hideous,” Haft says. The biopsy came back fine, but Haft needed the lump removed to be certain. Haft had an MRI, during which doctors placed a wire in her breast to pinpoint the lump, and then surgery under general anesthesia, which left painful scar tissue behind. Haft, now 42, has since had two more false-positive mammograms, followed by painful mammogram-guided biopsies: “Every time they find something, Im petrified.”

False positives like Hafts are remarkably common. About 1 in 10 mammograms in the United States find something thats considered abnormal. “But of those abnormal mammograms, 90 percent are false positives,” says Noel T. Brewer, PhD, an assistant professor of health behavior at the Gillings School of Global Public Health at the University of North Carolina at Chapel Hill. That means that of all the terrifying it-may-be-somethings, 90 percent of the time, its nothing.

The false-positive rate in the United States is about twice as high as it is in Canada, and about 10 times higher than in the Netherlands, Brewer says. There are two reasons why, he says: doctors in the United States tend to more frequently designate mammograms as abnormal, and most countries dont routinely screen women in their 40s, who are at relatively low risk for breast cancer (just 1.4 percent will be diagnosed over a 10-year period, according to the Centers for Disease Control and Prevention). Even with less-frequent screenings, though, Brewer says, “Women in these other countries do not die of breast cancer at higher rates than women in the United States.”

An abnormal mammogram is often followed by another mammogram, an MRI or a biopsy—which may be the removal of tissue with a needle, but often means surgery like Hafts. This sometimes involves general anesthesia and carries the risk of bruising, infection, and bleeding, as well as a change in the appearance of the breast.

And then there is the psychological impact. In one survey, 37 percent of women who had a false positive described the experience as “very scary” or the “scariest time of my life.” “It could be easy to dismiss the fear women feel in these situations—to say, ‘Look, everything turned out fine,” Brewer says. “But the anxiety produced by a false-positive result can be quite profound and long-lasting.”

Overdiagnosis alert
And then theres overdiagnosis, which can damage your health more directly. “Overdiagnosis is when we find a cancer that would remain dormant or even go away if left untreated, or one that is growing so slowly that it would never cause symptoms during your lifetime,” Dr. Welch explains.

“We used to think that all cancer is relentlessly progressive, that it will get worse and worse until its cured or until it kills you,” adds Russell Harris, MD, professor of medicine at the University of North Carolina at Chapel Hill School of Medicine, who served on the task force.

“For some cancers thats true. But were finding that for many, its not.” Thats because there are different forms of this disease. Some breast cancers grow slowly, do not spread, and may even shrink on their own. Others grow very fast and warrant aggressive treatment.

“The problem is, doctors cant tell the difference between these types of cancer, at least at first,” says Laura Esserman, MD, director of the Carol Franc Buck Breast Care Center at the University of California, San Francisco. “So they end up treating them all.” A watch-and-wait approach, Dr. Esserman says, may be prudent for certain cancers, but those involved dont always want to risk taking the wrong course.

Overdiagnosis would be no big deal if treatment were risk-free, but its not, Dr. Harris says. In addition to surgery, side effects from radiation include fatigue, soreness, swelling, and skin changes; in rare cases, it may damage the lungs or heart.

Chemotherapy—which can bring nausea and vomiting, hair loss, fatigue, and mouth sores—may, in the worst case, lead to nerve problems; harm the heart, the kidneys, or the lungs; and promote the development of a secondary cancer. For a woman whose tumor would never harm her, these treatments are the far-greater harm. And this chain of events all started with a mammogram.

So now what?
Hence the task forces new recommendations. In a nutshell, the reasoning goes, if you dont find as many abnormalities—which in all likelihood are nothing—you wont be subjected to needless procedures and will avoid pain and anxiety. Among other things, the guidelines advise against self-exams and say that women ages 50 to 74 should get screened every two years (not yearly). Most controversially, they recommend against routine mammography for average-risk women in their 40s.

This way of thinking is hard to accept, especially if youve known a younger woman who has had breast cancer. But the new guidelines may not alter your routine. If you notice a lump, discharge, or a change in your breasts shape, see your doctor immediately, as always. And if you belong to a high-risk group, the evidence comes down overwhelmingly on the side of frequent screenings. (Youre at high risk if, for instance, you have a mother or sister who was diagnosed at an early age, or if youve tested positive for the genetic mutations BRCA1 or BRCA2.)

If you are not at high risk, youre left with much to sort out. For women ages 50 to 74, most experts agree that the benefits of regular screening, albeit every two years, outweigh its risks. For women ages 40 to 49, the risks and benefits pull almost even, so that “deciding to get a mammogram, and deciding to not get a mammogram, are both sensible choices,” Dr. Welch says. Your decision about whether to get screened and, if so, how often, might simply come down to what you can tolerate. Would you rather assume the relatively high likelihood that youll be overdiagnosed or the relatively low risk of a dangerous tumor being found too late to treat? (Exposure to radiation each year was not something that the task force felt was as big a problem as overdiagnosis.)

Its enough to make you long for the old, simple slogans promoting regular screening. “Screening is complex because cancer is complex,” Dr. Esserman says.

“Its in the nature of medical research to learn more, to update our old ideas, and to try to use that new information to improve the care we offer to patients.” The good news is that much of the money devoted to breast cancer research is yielding advancements that will eventually ensure that only women who need treatment get it. (See “What the Future Holds,” on page 6.)

For Haft, who is dreading her next mammogram, the future cant come soon enough. “If they find something and it turns out to be nothing, Ill consider myself lucky,” she says. “But Id be luckier not to have to go through all that worry again.”

How to Nail Down Your Doctor
“Talk to your doctor,” the catchall advice experts give, sounds like a cop-out. But in the case of breast cancer screening, having a good sit-down about whats best for you personally is the way to go. Some topics to toss out on the exam table:

Family history.
If you have a mom or sister who had breast cancer that was diagnosed before menopause, you are at above-average risk. Some (but not all) experts advise you to start getting screened 10 years before the age at which your relative was diagnosed. Ask your doctor where she stands on that rule, and find out if your background warrants genetic testing for BRCA mutations.

Past health status.
Women who had chest radiation (in their younger years) or certain breast conditions may need to be screened more often.

If youre in your 50s or 60s, you need routine screenings, but whether these should be annual or biennial is something to discuss. If youre in your 40s, Russell Harris, MD, advises asking your doctor: “If 100 women with the same profile as me were screened every year for the next 10, how many will be helped and how many will be hurt?” You might find that the number of those helped is so low that youre OK betting you wont be one of them. If not, you can opt to be screened.

The freak-out factor.
If you received an abnormal mammogram result that turned out not to be cancer, could you shrug off the false alarm—or would the fear of what might have been stay with you? Asking yourself this question will ensure that you make the right decision for you.

What the Future Holds
Mammography has contributed to the yearly declines in breast cancer deaths since 1990. While theyre not perfect, theyre the best tool we have in wide use. Heres whats coming down the pike.

Better identification of tumor type.
Right now, we focus on a cancers stage—early or late. Soon we may pay more attention to whether its a slow-growing tumor or a fast-growing type with a significant risk. Researchers are develop-ing blood tests that will use changes in genetic mate-rial or levels of particular proteins to indicate the presence of a tumor, and molecular profiling to determine whether the tumor is likely to be aggressive. When more is known about the nature of a tumor, treatments can be more targeted: potentially deadly cancers will be treated vigorously, while indolent cancers will receive more restrained measures.

Better definition of “high risk.”
Scientists are working on other tools that will refine what high risk really means, to make sure that only the women who are truly at high risk are screened often and treated aggressively. Laura Esserman, MD, for example, now screens her patients who have a BRCA gene mutation once every six months, alternating mammograms with MRIs. She and her colleagues are also working to reduce the number of unnecessary biopsies they perform on low-risk women.

Putting it all together.
Sophisticated computer models will take all the information about a patient and her tumor and analyze it in a way thats more comprehensive than a doctor might be able to using clinical judgment alone.