Medical audit after 26,711 breast imaging studies - Improved rate of detection of small breast carcinomas (Classified as Tis or T1a,b)

BACKGROUND. Patients with breast carcinomas 1 cm or smaller are known to ha ve the highest long term survival rates. This pathologic measurement was us ed as a quality indicator of the performance of different reporting radiolo gists. METHODS. A total of 26,711 diagnostic breast imaging studies were performed over a period of 5 years. Within the first 18 months, several general radi ologists reported mammograms, whereas during the rest of the evaluated peri od only 1 radiologist was responsible for all mammography reporting. Radiol ogic findings leading to open biopsy were correlated with the histologic re sults. The cancer sizes from the histologic reports were recorded, and the number of Tis, T1a, and T1b cancers were correlated with all cancers found at open biopsy. The change in the relative percentage of small cancers was evaluated, along with the positive predictive value (PPV). RESULTS. Between 1991 and 1995, 26,711 breast imaging studies were performe d. This resulted in 2698 open biopsies with 620 breast carcinomas detected. In the first 2 years, the percentages of small cancers detected (Tis or T1 a,b) were 27.2% and 25.7%, respectively. In the third, fourth, and fifth ye ars, the percentages increased to 38.8%, 34.5%, and 38.8%, respectively. At the same time, the PPV increased slightly, from 0.23 in 1991 to 0.27 in 19 95. CONCLUSIONS. The detection of curable early stage breast carcinomas require s the dedication and commitment of a small group of radiologists who are wi lling to spend most of their time on this single subject. This will increas e considerably the number of early stage cancers found and reduce the numbe r of false-positive diagnoses. [See editorial counterpoint on pages 2430-1 and reply to counterpoint on pages 2432-3.] Cancer 1998;83:2516-20. (C) 199 8 American Cancer Society.