Digital breast tomosynthesis screening produces lower interval breast cancer rates compared to traditional digital mammography, according to a new analysis published Tuesday. The findings add to growing evidence supporting DBT as a top cancer screening tool.
Prior investigations have shown DBT to have a higher sensitivity for detecting breast cancers, yet some have argued these additional findings may contribute to overdiagnosis. Comparing more than 40,000 women who underwent mammography and DBT, the latter decreased the number of cancer cases detected between screenings.
And given many of these aggressive cancers had non-favorable characteristics, Swedish researchers believe screening with DBT may translate into real-world benefits, they explained April 6 in Radiology.
“One could speculate that some of the additional cancers detected in DBT screening would have been diagnosed as interval cancers if not detected by DBT,” lead author Kristin Johnson, MD, a radiology resident at Skåne University Hospital in Malmö, said in a statement.
Many screening programs mandate interval cancer detection rate reporting to ensure effectiveness, the authors noted. A lower rate, as detailed in this prospective study, may be the result of detecting additional aggressive cancers and ultimately could reduce disease mortality.
Johnson et al. based their conclusions on Sweden’s population-based Malmö Breast Tomosynthesis Screening Trial and an age-matched control group of women who underwent DM at the same healthcare center. The nearly 15,000 who underwent DBT and digital mammography between 2010 and 2015 were compared to more than 26,000 DM-only patients in the control arm.
Screening women with DBT and mammography yielded an interval cancer rate of 1.6 per 1,000 screened, the authors reported, far lower than 2.8 per 1,000 in the mammography-only cohort.
The group said their results support the potential for DBT to replace mammography in the future. Johnson did note, however, that interval cancer rates are not the only important statistic when analyzing digital breast tomosynthesis.
“Other factors, such as cancer types detected and cost-benefit, have to be taken into account,” Johnson, also a PhD student at Lund University in Sweden, added on Tuesday.
With that in mind, the researchers are moving forward with a cost-benefit analysis trial which will also assess DBT’s impact on false-positive recall rates.
Matt joined Chicago’s TriMed team in 2018 covering all areas of health imaging after two years reporting on the hospital field. He holds a bachelor’s in English from UIC, and enjoys a good cup of coffee and an interesting documentary.