THE NEW-MEXICO MAMMOGRAPHY PROJECT - SCREENING MAMMOGRAPHY PERFORMANCE IN ALBUQUERQUE, NEW-MEXICO, 1991 TO 1993

BACKGROUND. This project was designed to collect and link population-b ased mammography and breast carcinoma data to assess the performance o f community mammography screening. METHODS. Computerized data were col lected from all radiology practices in Albuquerque, New Mexico. The da ta were linked by computer match to breast carcinomas in a statewide c ancer registry. Analysis is based on 126,466 screening mammogram studi es performed on 87,443 female residents of New Mexico between the ages of 35 and 84 by 5 radiology groups. Sensitivity, specificity, positiv e predictive value, and call back rates were calculated as indicators of the discriminative performance of mammography. Carcinoma size and s tage distribution were analyzed as outcome measurements. RESULTS. The computer match linked 634 breast carcinomas to the 126,466 screening m ammogram series. The community-wide sensitivity was 79.9%, and specifi city was 90.5%. The predictive value of an abnormal screen was 4.3%, a nd that of a biopsy recommendation result was 16.9%. The call back rat e was 11.4%. The median invasive breast carcinoma size was 15 mm, 20.3 % of carcinomas were in situ, 18.3% were lymph node positive, and 68.1 % were Stage 0 or Stage I. CONCLUSIONS. Mass screening mammography as practiced in Albuquerque, New Mexico, is able to detect breast carcino mas at early, treatable stages. The stage distribution of carcinomas i s similar to that seen in successful clinical trials. However, measure s of mammography performance show lower sensitivity, more additional s tudies, and more biopsy recommendations in this community setting than have been reported by expert mammographers. (C) 1996 American Cancer Society.