Women who started getting mammograms at younger ages had an increased risk of false positive results, researchers found. Slightly more than 60% of women who started annual mammography in their 40s and 50s and continued screening for a decade would get at least one false positive result. That's compared with only about half of women who began screening in their late 60s. Overall, 19% of women in the study were overdiagnosed, meaning that a tumor was detected that was later found to be harmless.
“Mammography screening appears to be associated with breast cancer mortality, but for some patients, the harms may outweigh the benefits,” concluded researchers from Harvard Medical School and Brigham and Women's Hospital in Boston. “In light of the harms and modest benefit of screening, as well as the substantial uncertainty surrounding their relative weight for individual patients, clinicians' efforts must focus on promoting informed screening decisions,” they said.
The study looked at randomized clinical trials dating from 1960 through January of this year. The findings were published April 2 in the Journal of the American Medical Association. The analysis follows a report released in February in the British Medical Journal, which contended that annual mammography in women ages 40 to 59 does not reduce death from breast cancer. In that study, researchers followed more than 89,000 women over the course of 25 years and found nearly the same number died whether or not they had received routine mammograms.
It is important that the information on mammography risks versus benefits are communicated clearly to women, Dr. Richard C. Wender, chief cancer control officer for the American Cancer Society, wrote in a blog post. “Women who value the opportunity to prevent a premature cancer death are willing to accept a high rate of abnormal mammograms, recalls, and biopsies to avoid a breast cancer death,” he said, noting that others may place greater value on avoiding such recalls, procedures and treatment for conditions that do not always lead to cancer.
Breast cancer is the most common cancer among American women. More than 232,000 new cases of invasive breast cancer will be diagnosed in women in 2014 and approximately 40,000 women will die from the disease this year, according to 2014 estimates.
“Learning to discuss risk and personal values poses a new challenge and will require new tools,” Wender wrote. “We are entering an era of personalized medicine, based not just on someone's DNA, but also based on a man or woman's personal values.”
Follow Sabriya Rice on Twitter: @MHSRice