Study Reveals Sustained Benefits of 3D Mammograms for Breast Cancer Screening

Digital breast tomosynthesis (DBT) displays thin sections of the breast from different angles, creating a semi-3D mammogram to help radiologists diagnose breast cancer. This technology was approved less than a decade ago, and it’s unclear whether its effectiveness for breast cancer screening is sustained over time and after a woman’s initial screening with DBT.

Now a team of investigators at Massachusetts General Hospital (MGH) has verified the long-term benefits of DBT, which includes fewer false-positives. The findings are published in Radiology.

For the study, researchers reviewed 99,582 two-dimensional digital mammograms (DM) in 55,086 women over three years before DBT was implemented and 205,048 DBT mammograms in 76,276 women over five years after DBT was implemented.

Compared with women who underwent DM, women who underwent DBT were less likely to need follow-up tests to clarify the presence or absence of breast cancer, which held true for both the first DBT exam and for DBT exams in subsequent years. DBT was also superior to DM in terms of specificity—or how well the screening test shows who truly does not have breast cancer—and this was sustained after the first exam. The authors also found that the highest rate of cancer detection occurred with a woman’s first DBT exam.

“We have observed fewer screening callbacks, which are a source of anxiety for our patients, with DBT than DM, and this benefit persists over multiple years and rounds of screening. Savings in health care expenses, time, and resources could also result from the decrease in false-positive findings,” said first author Manisha Bahl, MD, MPH, of MGH’s Department of Radiology. “Our study is one of the largest longer-term studies of screening with DBT, and we hope that this information is used to inform policies for integrating this relatively new technology into population-level screening programs.”

Additional co-authors of the study include Sarah Mercaldo, PhD, Pragya A. Dang, MD, Anne Marie McCarthy, PhD, Kathryn P. Lowry, MD, and Constance D. Lehman, MD, PhD.

About the Massachusetts General Hospital

Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH Research Institute conducts the largest hospital-based research program in the nation, with an annual research budget of more than $1 billion and comprises more than 8,500 researchers working across more than 30 institutes, centers and departments. In August 2019 the MGH was once again named #2 in the nation by U.S. News & World Report in its list of "America’s Best Hospitals."