Tomo plus mammo finds more cancers, reduces recall rates

Tomosynthesis added to digital mammography is associated with an increase in the detection of breast cancers as well as a decrease in call-back rates, according to a study published in the June 25 issue of the Journal of the American Medical Association.

Sarah Friedewald, M.D., of Advocate Lutheran General Hospital, and colleagues, conducted the study using data from 13 health centers in which they compared outcomes for women screened for breast cancer the year before tomosynthesis was introduced at each breast center to outcomes for those screened after the introduction of tomosynthesis.

They evaluated a total more than 450,000 examinations--281,187 digital mammograms and 173,663 digital mammograms plus tomosynthesis--and found that with the addition of tomosynthesis one extra cancer was detected for every 1,000 breast exams performed. Additionally, 16 fewer women were asked back for additional screening per 1,000 breast exams.

"This study confirms what we already know: 3-D mammography finds more of the invasive, harmful cancers we want found and saves women the anxiety and cost of having additional exams for what turns out to be a false alarm," study co-author Donna Plecha, M.D., director of breast imaging at University Hospital Case Medical Center in Cleveland, said in an announcement. "This study provides us with firm data that 3-D mammography is a better test for detecting breast cancer early when it is treatable."

Similar research published in Radiology determined tomosynthesis to be effective at reducing recall rates in breast cancer screening. In that study, researchers compared recall and cancer detection rates in two groups of women: those receiving digital mammography alone and those who underwent tomosynthesis as well as mammography. They found that the cancer detection rate was 5.7 per 1,000 in patients receiving tomosynthesis, compared with 5.2 per 1,000 in patients receiving mammography alone. The addition of tomosynthesis resulted in a 30 percent reduction in the overall recall rate, from 12 percent for mammography alone to 8.4 percent in the tomosynthesis group.

In an editorial accompanying the new study, Etta Pisano, M.D., of the Medical University of South Carolina and Martin Yaffe, Ph.D., of the University of Toronto, suggested that those who question the benefits of mammography compared to its associated harms might not be convinced by the evidence presented.

Still, they said, the new research adds "considerable evidence to the current knowledge of how tomosynthesis performs in everyday practice."

"For those who interpret the evidence to suggest that screening saves lives without undue false-positive results and overdiagnoses, this study contributes to the case for tomosynthesis over digital mammography," they said.

To learn more:
- read the study in JAMA
- see the announcement
- check out the editorial in JAMA