Computer simulation crunches numbers on ACS, USPSTF breast cancer screening recommendations

One of healthcare’s most common debates is which of the many different breast cancer screening guidelines women should follow to receive the best possible care. The authors of a new study in the American Journal of Roentgenology ran a Monte Carlo computer simulation to put the screening mammography guidelines released by the American Cancer Society (ACS) in 2015 up against the updated recommendations released by the U.S. Preventive Services Task Force (USPSTF) in 2016.

“Screening mammography clearly has the potential to cause both benefit and harm,” wrote Kimbroe J. Carter, MD, of St. Elizabeth Youngstown Hospital in Ohio, and colleagues. “The challenge in developing a screening guideline is to make the best use of its benefits while avoiding harm at a reasonable cost. A solution depends in part on the design of a screening program.”

While the ACS guidelines call for a “mixed strategy that combines annual and biennial screening depending on a woman’s age,” the USPSTF recommended fixed biennial screening. So what did the computer simulation have to say about the two different recommendations?

Overall, the mixed annual-biennial strategy developed by the ACS got the nod, though it was close. “Some skepticism surrounds screening mammography, but current screening appears to offer more benefit than harm and the ACS 2015 guideline outperforms the USPSTF 2016 guideline in most scenarios,” the authors wrote.

The simulation found that in a patient’s lifetime, following the ACS 2015 guideline would result in a mean breast cancer mortality per individual of 2.2 percent. This is compared to 2.5 percent for following the USPSTF 2016 guideline.

Following the ACS 2015 guideline, however, results in a higher number of mean false-positive screens per individual (1.41 vs 0.79) and more unnecessary biopsies (0.072 vs 0.041). These findings, the authors added, accurately reflect the ongoing debate about the frequency of screening mammography.

“There has been increasing recognition of adverse effects of false-positive findings and unnecessary biopsies on women's well-being,” the authors wrote. “These negative effects of screening were recognized as significant and contributed to the periodic revisions of screening guidelines to include later start ages, earlier end ages and less frequent screening.”