On April 20, the U.S. Preventive Services Task Force posted for public comment its revised draft recommendations for how frequently women should have screening mammograms. As a physician who works to diagnose breast cancer, I had hoped that the task force recommendations would have advocated for annual screening mammography starting at age 40 to assist us in early detection. The results are very disturbing, and they will lead to increased morbidity and mortality from breast cancer.
We know that approximately 12 percent of breast cancers are diagnosed in women in their 40s. These women are known to have cancers that are more difficult to identify and that are more aggressive. They often have young children, early careers and long lives ahead. In addition to these critical factors, the high costs of late-stage treatment, which may include radiation and chemotherapy, must be considered.
Current breast screening guidelines vary, but the American Cancer Society, American College of Obstetricians and Gynecologists, National Comprehensive Cancer Network, and National Cancer Institute (NCI) recommend beginning screening at age 40. All of these, except the NCI, recommend annual screening; the NCI recommends a one- to two-year interval. The 2015 task force recommendations suggest beginning screening at age 50, continuing every two years until age 74.
Discussion over the last few years has caused widespread confusion about early cancer detection by drawing attention to possible overtreatment, the potential harms of false alarms from screening mammography and the cost of screening programs. These are well-known to be overstated in many publications and in the current task force recommendations. To address costs and tailor screening, some advocate using risk-based approaches — models that take into account age, family history, health and other factors — to identify women at highest risk. However, at this time, no single consistent, high-quality prediction model exists. Regarding overtreatment, there are no scientific data distinguishing which cancers will have fatal outcomes and which are indolent. In this setting, we cannot afford to forgo diagnosis and treatment to women whose lives may depend on it.
It is critical that the guidelines account for the value of early diagnosis in young women in their 40s. The value of screening continues with age, given the fact that aside from being female, our second most important risk factor is our age. If we stop screening women as they age and their risk increases, we may miss life-threatening cancers.
The suggestion that mammograms and annual screenings lead to more harm than benefit is concerning and is not supported by current scientific understanding of the natural history of breast cancer.
Dr. Susan Harvey is the director of the Johns Hopkins Section of Breast Imaging.