Annual mammograms questioned
CHICAGO — An influential group’s new recommendations about mammograms for younger women set off a furious debate Monday that left women without clear guidance about how best to protect their health.
The U.S. Preventive Services Task Force, a government-sponsored group whose work is closely followed by doctors and insurance companies, is now advising healthy women in their 40s may not need routine breast screening.
Mammograms help save lives, but they also can be unreliable, identifying benign growths as cancerous, missing other tumors that are malignant and sometimes leading to medical interventions of questionable benefit.
For younger women at low risk of the disease, the benefits are not large enough to endorse routine mammograms, the task force said in materials published Monday in the Annals of Internal Medicine.
Instead, 40-something women should make individual decisions after weighing the pros and cons, the group said.
“No one is saying that women should not be screened in their 40s,” said Dr. Diana Petitti, vice chair of the task force. “We’re saying there needs to be a discussion between women and their doctors.”
The task force also advised women 50 and older to get mammograms every two years instead of every year, and said evidence isn’t sufficient to determine a course of action for women 75 and older.
Breast cancer specialists immediately denounced the new recommendations, warning they could undermine advances in detecting and treating breast cancer early. Deaths from breast cancer have dropped 30 percent since 1990.
“This will be disastrous for women’s health,” said Dr. Daniel Kopans, senior radiologist in the breast imaging division at Massachusetts General Hospital.
“It’s arrogant and irresponsible,” said Dr. Robert Schmidt, a professor of radiology at the University of Chicago Medical Center. “It’s wrong to keep changing recommendations and give conflicting messages to women.”
Underscoring divisions over the issue, both the American Cancer Society and the National Cancer Institute said they would not follow in the task force’s footsteps. Both organizations recommend routine mammograms for women starting at age 40.
After a review of the evidence, “we see no reason at this point to alter our guidelines,” said Dr. Len Lichtenfeld, the cancer society’s deputy medical officer.
“It is very confusing,” said Careese Anderson, 48, of Chicago, who has been getting annual mammograms at the University of Chicago for the past eight years. “You hear one thing all these years and it’s scary when they start saying something else.”
Evaluating the scientific evidence on the benefits of mammograms has challenged experts for more than 15 years. Eight “gold standard” medical trials have assessed the impact of mammography on breast cancer deaths, but most of the studies have significant flaws, experts say.
Fundamentally, the difference of opinion comes down to “a judgment call” about potential benefits and harms, Petitti said — a call doctors will also need to make when talking to patients.
“Our breast cancer group will review this very carefully,” said Dr. William Gradishar, an oncologist who directs the breast cancer program at Northwestern University’s Feinberg School of Medicine.
A new scientific analysis and modeling study published Monday along with the new recommendations found women in their 40s who were offered the opportunity to get mammograms were 15 percent less likely to die of breast cancer than those who weren’t.
That’s an important advantage, but it needs to be seen in context. The risk a 40-year-old woman will die of breast cancer in the next 10 years is very small — just 0.19 percent, according to data from the National Cancer Institute. (Over her entire lifetime, the risk rises to 2.86 percent.) And the risk a woman of 40 will be diagnosed with invasive breast cancer before her 50th birthday is 1.44 percent.
Most women vastly overestimate these risks, research shows.
Meanwhile, the chance of “false positive” results (which appear to signal cancer but turn out to be incorrect) is 60 percent higher in 40-something women than in women in their 50s, in part because younger women’s breasts are denser and harder to evaluate. Rates of over-diagnosis — the detection of lesions that would never become cancerous — can run as high as 10 percent, the analysis said.
These false alarms expose many women to extra medical tests and procedures, which can be expensive and anxiety-producing, without yielding any clear health benefits.
One statistic the new analysis doesn’t detail is how many women in their 40s might die of cancer if they decided to forgo screening until they turned 50.
