Frequency of impalpable prostate adenocarcinoma and precancerous conditions in Greek male population: an autopsy study.

A series of 212 prostate specimens of men dead between August 2002-August 2004, have been sectioned in consecutive autopsies and subjected to whole mount analysis in purpose to determine the epidemiology of impalpable prostate cancer in Greece. Impalpable prostate carcinomas were found in 40 cases (18.8%) most in the peripheral region. In all, 29 of 40 impalpable cancers (70.7%) had volume less than 1 cm3. Most of impalpable carcinomas were of favorable (Gleason score 2-4) or intermediate (Gleason score 5 and 6) histological type (55 and 27.7%, respectively) while only five (12.5%) were undifferentiated (Gleason score 7 and 8). In all, 24 (60%) of the 40 impalpable carcinomas were multifocal and consisted of two or more foci, most of small size (<0.5 cm3). Most of the impalpable cancers found in this autopsy study were potentially insignificant tumors (relatively low volume, favorable or intermediate histological pattern and absence of invasiveness). Prostate intraepithelial neoplasia (PIN) coexisted with impalpable carcinomas, in almost half of the cancer-positive specimens. There was a positive correlation between PIN foci and coexistent cancer foci in most of the cases. Frequency rate and pathological features of both entities show significant variations in medical literature. Since the incidence of clinical prostate cancer in Greece is relatively low, and according to our autopsy findings, it is plausible that the frequency of clinical prostate cancer in a certain population could be related to the prevalent model of impalpable cancer as well as to the frequency and extend of the precancerous lesions.