Nation-wide data on screening performance during the transition to digital mammography: Observations in 6 million screens

Purpose: To critically evaluate and confirm previous results regarding the diagnostic accuracy of digital mammography screening (DM), compared to screen-film mammography (SFM) in the whole Dutch screening programme, in the period of 2004-2010, during which a full transition from SFM to DM was made. Materials and methods: 1.5 million DM and 4.6 million SFM were read in the Dutch national breast cancer screening programme in the period of 2004-2010. We evaluated recall rate, detection rate, positive predictive value and tumour-size distribution for younger and older women, for first time participants and women having a timely subsequent screen. We compared DM screens read by radiologists reading DM and SFM (DM-group) to SFM screens read by these radiologists (SFM-group) and to SFM screens re Results: Recall rate was 2.0% (95% confidence interval (C. I.): 2.0; 2.1) in the DM-group, compared to 1.6% (95% C. I.: 1.6; 1.6) in the SFM-group and 1.6% (95% C. I.: 1.5; 1.6) in the SFM only-group. The overall detection rates were 5.9/1000 screens (95% C. I.: 5.7; 6.0) in the DM-group, 5.1/1000 screens (95% C. I.: 5.0; 5.2) in the SFM-group and 5.0/1000 screens (95% C. I.: 5.0; 5.1) in the SFM only-group. Detection rate rose most markedly in younger women (age 49-54) from 4.0/1000 screens to Conclusion: In accordance to previous, smaller, studies, we can confirm that DM has a higher detection rate compared to SFM, at the cost of a higher recall rate and lower PPV. More DCIS and a higher fraction of very small tumours were detected with DM, which has positive consequences for the stage shift as a result of mass screening. (C) 2013 Elsevier Ltd. All rights reserved.