Screening outcome and surgical treatment during and after the transition from screen-film to digital screening mammography in the south of The Netherlands.

Abstract

We determined screening outcome of subsequent screens during and after the transition from screen-film mammography (SFM) to full-field digital mammography (FFDM). A consecutive series of 102,863 subsequent (SFM screens with a prior SFM screen (SFM-SFM cohort), 91,941 FFDM screens with a prior SFM screen (FFDM-SFM cohort) and 90,407 FFDM screens with a prior FFDM screen (FFDM-FFDM cohort) were obtained between January 2006 and July 2013. The referral rate and cancer detection rate (CDR) per 1,000 screens were higher at FFDM-SFM than at SFM-SFM (2.7% vs. 1.2% (p < 0.001) and 7.0 vs. 4.9, p < 0.001), at the expense of a lower positive predictive value (PPV) of referral (25.8% vs. 39.6%, p < 0.001). These parameters were comparable for FFDM-SFM and FFDM-FFDM. Ductal carcinoma in situ (DCIS) and invasive cancer rates increased during transition and remained stable after transition. The rate of DCIS of intermediate grade increased during the transition from 0.2 per 1,000 screened women at SFM-SFM to 0.6 at FFDM-SFM (p < 0.001) and 0.5 at FFDM-FFDM (p = 0.001). Compared to SFM-SFM, a significantly higher rate of invasive cancers were stage T1a-b at FFDM-SFM (p < 0.001) and FFDM-FFDM (p < 0.001). Breast conserving surgery rates increased during transition (p < 0.001) and remained stable afterwards. The CDR and referral rate remained significantly higher at FFDM than at SFM, at the expense of a decreased PPV of referral. During transition, DCIS was more often of intermediate grade and invasive cancers were of smaller size.