P1-309 Differences in radiological patterns, tumour characteristics and diagnostic precision between digital mammography and screen-film mammography in four breast cancer screening programs in Spain
Anabel Romero, Laia Domingo, Francesc Belvis, M Sánchez, Joana Ferrer, D. Salas, J Ibañez, A Vega, Ferrán Ferrer, Mas Laso, Francesc Macià, Xavier Castells, María Sala · Journal of Epidemiology & Community Health · 2011
Introduction Since 2000 Digital Mammography (DM) has been commercially available and implemented in many breast cancer screening programs. Although available information suggests that differences, if exist, are low, complete evaluation of DM is needed to perform a more accurate balance of risks and benefits of these programs. Our purpose was to compare tumour characteristics between cancers detected with Screen-Film Mammography (SFM) and DM, and to evaluate changes on positive predictive values (PPVs), for further assessments, for invasive procedures and for different radiological patterns in recalled women. Methods 242 838 screening mammograms (171 191 SFM and 71 647 DM) from 103 613 women aged 45–69, performed in four population-based breast cancer screening programs in Spain, were included. Tumour characteristics of each group were compared, as well as PPVs among recalled women and according radiological patterns. Results In first and successive screenings percentages of DCIS, although not significant, were higher in DM group: 17.6% vs 13.3% (p=0.580) and 19.6% vs 13.5% (p=0.115), respectively. For masses, asymmetries and calcifications PPVs were higher in DM group, being statistically significant in masses (5.3% vs 3.9%; proportion ratio: 1.37 95% CI 1.08 to 1.72). Among cancers detected by calcifications, the percentage of DCIS was higher in DM group, being nearly significant (60.3% vs 46.4%, p=0.060). Conclusion PPVs were higher when DM is used, both for further assessments and for invasive procedures, with similar cancer detection rates and without statistically significant differences on tumour characteristics. Most relevant improvements on PPVs were detected for radiological patterns of masses.