Medical audit after 26,711 breast imaging studies

Abstract
Patients with breast carcinomas 1 cm or smaller are known to have the highest long term survival rates. This pathologic measurement was used as a quality indicator of the performance of different reporting radiologists. A total of 26,711 diagnostic breast imaging studies were performed over a period of 5 years. Within the first 18 months, several general radiologists reported mammograms, whereas during the rest of the evaluated period only 1 radiologist was responsible for all mammography reporting. Radiologic findings leading to open biopsy were correlated with the histologic results. 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). Between 1991 and 1995, 26,711 breast imaging studies were performed. This resulted in 2698 open biopsies with 620 breast carcinomas detected. In the first 2 years, the percentages of small cancers detected (Tis or T1a,b) were 27.2% and 25.7%, respectively. In the third, fourth, and fifth years, 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 1995. The detection of curable early stage breast carcinomas requires the dedication and commitment of a small group of radiologists who are willing to spend most of their time on this single subject. This will increase considerably the number of early stage cancers found and reduce the number of false-positive diagnoses. [See editorial counterpoint on pages 2430-1 and reply to counterpoint on pages 2432-3.]