Prospective characterization of pathological features of prostatic carcinomas detected via serum prostate specific antigen based screening.

ABSTRACT

PURPOSE: Many small (less than 0.5 cc), well differentiated, organ-confined prostate carcinomas remain clinically undetected during the life of the patient and are identified only at postmortem examination. Thus, these cancers are often called latent or autopsy cancers. There is concern that serum prostate specific antigen (PSA) based screening may preferentially detect these cancers. There are limited prospective data concerning the pathological features of carcinomas of the prostate detected in a screening program. We determined if prostatic carcinomas detected via PSA based screening resembled autopsy cancers. MATERIALS AND METHODS: We assessed the pathological features of carcinomas in 100 consecutive, completely embedded radical prostatectomy specimens from men whose cancer was detected in a PSA based screening program. The tumors were evaluated for pathological stage, surgical margin status, Gleason histological grade and intraglandular tumor extent (morphometrically quantified as percentage carcinoma and tumor volume). RESULTS: Of 100 carcinomas 68 (68%) were larger than 0.5 cc in volume (mean 1.7, range 0.1 to 10.7). Mean amount of carcinoma in the surgical specimen was 10.3% (range 0.1 to 41.6). Of the 100 carcinomas 94 had a Gleason score of 5 to 8 (mean 5.7) and only 6 (6%) were well differentiated (Gleason score of 4 or less). Locally advanced disease was noted in 41 cases (41%) as judged by the presence of extracapsular carcinoma and/or cancerous surgical margins. CONCLUSIONS: We concluded that the pathological features of most prostatic carcinomas detected via PSA based screening do not resemble those of autopsy cancers, and that most prostatic cancers detected in screening programs are likely to be clinically important.