New research shows benefits of beginning annual screening mammography at 40

Starting annual screening mammography for breast cancer at age 40 helps detect a significant number of cancers, according to a recent study published in the American Journal of Roentgenology.

Some advocacy groups, including the American College of Radiology, recommend starting annual screening at age 40, while other groups, such as the U.S. Preventive Services Task Force (USPSTF), recommend women wait and begin biennial screening at age 50.

“This information could be used clinically when health care providers engage women in conversations regarding when to initiate routine screening mammography,” wrote lead author Jenifer A. Pitman, Weill Cornell Medical College in New York, and colleagues. “It also logically supports the long-term ACR recommendation of starting annual screening mammography at age 40.”

The retrospective study included data collected from June 2014 to May 2016 at a single practice. Out of more than 32,500 screening mammograms, more than 808 biopsies were recommended, leading to 224 breast cancers. Pitman et al. found that more than 18 percent of the screen-detected breast cancers were found in women ages 40 to 49. Women ages 40 to 44 and ages 45 to 49 had similar cancer detection rates, “supporting a similar recommendation for both cohorts.”

“If 40- to 44-year-old women in our study had chosen to follow the 2015 [American Cancer Society] recommendations and waited until age 45 to start routine screening instead of undergoing mammography in their early 40s, then 8.9 percent of screen-detected breast cancers could have been missed,” the authors wrote. “If the 40- to 49-year-old women in our study had chosen to follow the 2016 (and 2009) USPSTF recommendations and waited until age 50 to start routine screening instead of undergoing mammography in their 40s, then 18.8 percent of screen-detected breast cancers could have been missed. These cancers would then be detected either clinically when palpable, or delayed detection would have occurred at later screening.”

Pitman and colleagues noted that their study did have several limitations. It was a retrospective review, for instance, it is unknown if the subjects were undergoing screening mammography every year or every other year. Additionally, it was not noted whether each patient was undergoing her first ever mammogram, which would have been “valuable” to the study.