The Screening Mammography Program of British Columbia: pilot study.

: A government-funded pilot project of high volume screening mammography was conducted in Vancouver, British Columbia. 7,100 women were screened over a 9-month period, averaging 43 women per day at a cost of $33.81 per woman screened. 722 (10%) had abnormal mammograms; 144 received breast biopsies; and 29 were diagnosed with cancer. The overall cancer detection rate was 4.1 per 1,000 (0.8 and 4.8 for incident and prevalent cases, respectively). The staging distribution for the 29 cancer cases was 5, 15, 8 and 1 for in situ, stage I, II and III, respectively.