Efficiency of single-view mammography: rate of interval cancer cases.

A nonselected population of women screened by single-view mammography was followed up to 2 years after screening, and breast carcinoma cases diagnosed were registered; 28,350 women were followed for 1 year. At screening, 132 invasive carcinoma cases were detected, and during the first year after screening, 10 cases were detected. According to an efficiency index, which takes into consideration both detections at screening and interval cases, the 1-year efficiency was 93%. The efficiency of single-view mammography for breast cancer screening was found to be satisfactory.