DBT detects more breast cancers than digital mammography

Breast cancer screening using digital breast tomosynthesis (DBT) detects more cancers than digital mammography (DM) in women of all density and age groups, according to new research published in Radiology.

The study’s authors noted that prior researchers had already compared the two modalities in many ways, but more statistics were needed for certain breast density groups.

“Prospective and retrospective studies have shown that the integration of DBT improves the cancer detection or recall rates for both fatty and dense breasts and in age groups relevant for mammography screening,” wrote lead author Bjørn Helge Østerås, MSc, Oslo University Hospital in Norway, and colleagues. “Data are limited in almost entirely fatty and extremely dense breasts.”

The study’s authors explored data from more than 24,000 women between the ages of 50 and 69 who received DM and DBT with independent double reading from November 2010 to December 2012. All information was part of the Oslo Tomosynthesis Screening Trial. Participants followed up for two years so interval cancers could be monitored.

Overall, DBT had a higher true-positive rate than DM for all density groups and age groups, a finding the authors said came from “the higher number of spiculated masses and architectural distortions found at DBT.”

DBT also had a lower false-positive rate than DM for all age and breast density groups, the authors noted, except for in patients with extremely dense breasts.

The team’s research did have certain limitations. It collected data from a single institution, for example, and the fourth edition of the American College of Radiology’s Breast Imaging Reporting and Data System (BI-RADS) was used for breast density categorization instead of the most recent edition.

“In the fifth edition, breasts are classified into a higher category if an area is dense and can obscure lesions,” the authors wrote. “The fifth edition might be more associated with a reduction in sensitivity in both DM and DBT as very dense areas can obscure cancers.”