A new study of screening mammography raises concerns about the risk of overdiagnosis, and subsequent overtreatment, from the screening procedure. The study, published online July 6, 2015, in JAMA Internal Medicine, found that the number of breast cancer diagnoses rose with increased screening but that the overall incidence of deaths from breast cancer remained the same. The study compared mammography rates of more than 53,000 women age 40 or older from 547 U.S. counties who were diagnosed with breast cancer in 2000 with deaths from breast cancer over a 10-year follow-up period. The researchers performed county-by-county comparisons of mammography screening, breast cancer incidence, and breast cancer death rates for the 10-year period. They found that as breast cancer screening increased, so too did the detection of breast cancer, particularly of small breast cancers, with no significant change, however, in breast cancer deaths. "The most prominent effect of screening mammography is overdiagnosis," the study authors conclude. While acknowledging the benefits of screening mammography to detect and treat breast cancer, they write that "the balance of benefits and harms is likely to be most favorable when screening is directed to those at high risk." An editorial accompanying the study says that patients and their providers are "left in a conundrum. Women will increasingly approach their physicians with questions and concerns about overdiagnosis, and we have no clear answers to provide." The editorial's authors recommend that physicians more clearly communicate the benefits of screening mammography, as well as its potential harms, such as overdiagnosis, "to help women make informed decisions regarding breast cancer screening mammography."

HRC Recommends: The goal of screening mammography is to reduce breast cancer deaths by detecting and treating cancers early in the course of the disease. But findings like those recently published in JAMA Internal Medicine underscore the screening procedure's limitations, such as the risk of overdiagnosis and overtreatment. Risk managers should ensure that their organization's protocols for breast cancer screening and treatment are consistent with recommended practices and that the protocols are reviewed regularly, as well as any time that recommended practices are modified.