Breast cancer screening with digital breast tomosynthesis - 4 year experience and comparison with national data

To determine if mammography combined with digital breast tomosynthesis (DBT), leads to superior performance in screening for breast cancer compared to digital mammography (DM) alone.

We retrospectively collected data from A) the results of population-based mammography-screening provided by the National Cancer Registry in Taiwan, and B) the results from all screening mammography performed with DBT from 2012 through 2015 at Kaohsiung Veterans General Hospital (VGHKS) since the institution of DBT at the end of 2011. This was compared data from 3 years with DM performed prior to DBT implementation. We calculated the results of medical audit of VGHKS and compared this with national data. Fisher's exact test is applied.

VGHKS data demonstrated a higher cancer detection rate (CDR) and positive predictive value 1 (PPV 1) than the national average. Most prominently in the year 2014, our CDR was 120% better than that of the national average. CDR ranged from 6.3 to 8.1‰ prior to the introduction of DBT, and following DBT implementation this improved to 8.5-11.4‰, reflecting a mean increase of 32.2%. Early cancer detection was 50% higher and node negative rate was 25% higher than the national average of latest year. A 17.8% reduction in recall rate (RR) was achieved due to a decrease in unnecessary recall.

There was a 32.2% increase in CDR and a 17.8% decrease in RR when DBT was used as an adjunct to DM, as compared to DM alone. CDRs were approximately twofold better than national average data. DBT was more effective at detecting cancer in ductal carcinoma in situ and stage 1.