Breast cancer is the most common cancer in women and the fourth leading cause of cancer death in the U.S. Annual mammograms have been widely promoted for women by many health advocates; however, experts say that for women with an average risk for breast cancer who don’t have symptoms, diagnostic exams should be administered strategically, as screening too frequently can do more harm than good.
In a recent evidence-based guidance statement published in “Annals of Internal Medicine,” the American College of Physicians (ACP) – an organization representing internal medicine physicians – says that average-risk women with no symptoms and who are between the ages of 50 and 74 should undergo a breast cancer screening with mammography every other year.
ACP found that annual mammography results in more harm than mammography every other year. Harms of breast cancer screening include over-diagnosis, over-treatment, false-positive results, radiation exposure, and radiation associated breast cancers and breast cancer deaths, as well as worry and distress from tests and procedures like breast biopsies.
ACP says that beginning at age 40, average-risk women without symptoms should discuss with their physician the benefits, harms, and their personal preferences of breast cancer screening with mammography before the age of 50.
“The evidence shows that the best balance of benefits and harms for the great majority of these women is to begin breast cancer screening with mammography at age 50 and continue every other year through age 74,” says Dr. Ana María López, a medical oncologist and president of ACP, who points out that this guidance does not apply to patients with prior abnormal screening results or to higher risk populations, such as women with a personal history of breast cancer or a genetic mutation known to increase risk.
About 20 percent of women diagnosed with breast cancer over a 10-year period will be overdiagnosed and likely overtreated. Overdiagnosis means a woman is diagnosed with breast cancer that would not have made her sick or led to her death if not diagnosed or treated (overtreatment). Therefore, finding this cancer is not of clinical benefit to the woman.
Screening guidelines such as the age to start and discontinue mammography, intervals between mammograms, and the role of alternative screening methods, have varied among organizations, complicating decisions about care for both patients and doctors. However, this new evidence-based guidance statement from ACP, which represents convergence across these differing recommendations, hopes to provide clarity and simplicity.
“Little difference exists in reducing deaths from breast cancer by screening every year versus screening every other year, while every-other-year screening substantially reduces harms,” says Dr. López. “Of course, decisions regarding routine breast cancer screening should be made by doctors and patients together.”