Performance of screening mammography: A report of the alliance for breast cancer screening in Korea

Objective: To analyze the diagnostic accuracy and trend in screening mammography in Korea. Materials and Methods: We retrospectively linked the information from hospitals participating in the Alliance of Breast Cancer Screening in Korea (ABCS-K) and the database of the National Cancer Screening Program. We calculated performance indicators, including the recall rate, cancer detection rate (CDR), positive predictive value (PPV), sensitivity, specificity, false-positive rate (FPR), and interval cancer rate (ICR). Changes in the performance indicators were calculated as the annual percent change with 95% confidence interval (CI). Results: We enrolled 128756 cases from 10 hospitals from 2005 to 2010. The recall rate was 19.1% with a downward trend over time (-12.1% per year; 95% CI, -15.9 to -8.2). The CDR was 2.69 per 1000 examinations, without a significant trend. The PPV was 1.4% with an upward trend (20.8% per year; 95% CI, 15.2 to 26.7). The sensitivity was 86.5% without a significant trend, whereas the specificity was 81.1% with an upward trend (3.3% per year; 95% CI, 2.1 to 4.5). The FPR was 18.9% with a downward trend (-12.4% per year; 95% CI, -16.2 to -8.4). The ICR was 0.5 per 1000 negative examinations without a significant trend. There were institutional variations in the diagnostic accuracy and trend except for the CDR, sensitivity, and ICR. Conclusion: The sensitivity and CDR of screening mammography in the ABCS-K from 2005 to 2010 were compatible with those for Western women. The recall rate, PPV and specificity, however, were suboptimal, although they showed significant improvements over this period. A further analysis is required to explain institutional variations.