Background: Reported incidences of various diagnoses made on needle biopsy of the prostate vary significantly in the literature, most of which has originated from large, academic medical centers.
Methods: We recorded all the prostate needle biopsy results from three community hospitals for 1990-1993 to determine the rates of, and trends in, various diagnoses in these practices.
Results: Hospital H1 (1,192 cases) halved the rate of atypical, nondefinitive diagnoses from 11.8% in 1990 to 5.7% in 1993 (P < 0.001). The rate at H2 (2,792 cases) remained essentially unchanged at 5.95+/-0.55%, and H3 (1,306 cases) went from 2.3% to 6.0% (0.1 < P < 0.2). In the setting of an atypical, nondefinitive diagnosis, H1 and H2 recommended repeat biopsy less than 7% of the time. H3 made this recommendation in an average of 22.1% of atypical cases. Annual rates of high-grade prostatic intraepithelial neoplasia (PIN) showed no trend over time, and averaged 2.0% (1.2-3.25%) at H1 and 1.2% (0.3-2.0%) at H2. The diagnosis was never made at H3. The fraction of cancers diagnosed as low-grade (Gleason sum < or = 4) showed a statistically significant decreasing trend over time at all three hospitals (P < 0.05). These data are compared with those from the Johns Hopkins Hospital (JHH), a large academic center in geographic proximity to hospitals H1-H3.
Conclusions: At these three community hospitals, we discerned (1) convergence to a rate of approximately 6.0% of atypical, nondefinitive diagnoses; and (2) a progressively more appropriate fraction of carcinomas diagnosed as low-grade on needle biopsy. The rates of diagnosis of high-grade PIN and recommendation of repeat biopsy varied. These rates of PIN, atypical, nondefinitive diagnoses, and low-grade cancer represent an assessment of diagnostic habits.