Too many diagnoses

Alex Eben Meyer

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Mammograms have long been considered one of the best screening tools for detecting breast cancer. But a new Yale study suggests that older women may need to reconsider whether the risks outweigh the benefits. Older women face unique challenges with screening, according to Ilana Richman ’20MHS—the leading investigator of this study, an assistant professor in internal medicine, and a health services researcher.  

The study was limited to women older than 70 years. Richman and her team quantified how often doctors found something worrisome on a mammogram—and how often, after further testing, that worrisome image turned out to be nothing. Doctors call this “overdiagnosis,” because the additional procedures lead to unnecessary anxiety and cost.

Among nearly 55,000 women screened across the US, nearly a third of those between the ages of 70 and 74 years were found to be overdiagnosed: additional tests revealed they did not have breast cancer or had cancers that wouldn’t cause symptoms. The rate of overdiagnosis for the women 85 years or older was above 50 percent. (The findings were published in the Annals of Internal Medicine.)

Current national guidelines—including from the US Preventive Services Task Force, the leading medical authority on preventive screenings—give no recommendations for or against breast cancer screening for women 75 and above. Richman says her study shows how important it is for older women to consult with their health providers and consider the potential benefits, as well as potential harms, of this screening. At the very least, she says, they should be aware that further testing may be unnecessary.