Quality Assurance of an Organised Screening Programme for Breast Cancer in Denmark 1991-2008.

Abstract

Abstract Background: The capital city of Copenhagen, Denmark, has had an organised programme for screening with mammography since 1991. All women resident within the area of uptake and aged 50-69, representing around 45000 women, are invited biennially, unless they actively have asked not to be invited. We have evaluated the programme with regard to the European guidelines for quality assurance in breast cancer screening and diagnosis, to assess performance and impact.Methods: The target population was identified through the national population register, identifying all women meeting the inclusion criteria in terms of age and place of residence, migration and death. The mammography programme supplied data on all invited women, participation and screening test results. Oncological data was retrieved from the National Cancer Register and the Danish Breast Cancer Group. Data was linked using the Danish unique personal identity number.Results: In the first invitation round (1991-1992) the invasive cancer detection rate was 10/1000 and was by the 8th invitation round (2006-2007) 8/1000. The in situ detection rate has been 1/1000 throughout the period. The programme sensitivity is approximately 70%. The detection rate of small tumours (≤ 10mm) was, on average, 39% over the first 4 invitation rounds and 62% by the 8th invitation round. The benign to malign ratio changed from 1:1.6 to 1:11.4, from the first to the 8th invitation round. Recall rates at initial screen dropped from 7% to 4% in the period, and for subsequent screens from 4% to 2%. The false positive rate was 5.5% in the first invitation round and had by the 8th invitation round dropped to 1.3%, with a cumulative risk of 15% over 8 rounds. In the 8th invitation round, there was 82% coverage, a participation rate of 61% and a long term adherence of 50%.Conclusions: The results for the majority of indicators were well within the recommended levels. There had been a significant improvement in the benign to malign ratio, despite that the false positive rate at assessment had decreased. The detection of small tumours had also improved significantly. Participation rates were, however, lower than recommended. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4005.