Latent carcinoma of prostate at autopsy in seven areas. Collaborative study organized by the International Agency for Research on Cancer, Lyons, France

TLDR

The study compared the frequency and characteristics of latent prostate carcinoma across seven regions using standardized, blind microscopic evaluation to minimize bias. The authors examined the morphology of 350 latent carcinomas in 1,327 prostates from these areas, employing standardized, blind microscopic methods. Latent prostate carcinoma was less frequent in Chinese populations than in Western Europeans and Jamaicans, with an intermediate frequency in Israelis and black Ugandans; small carcinomas occurred in about 12 % of cases regardless of age, while larger tumors rose sharply with age and varied by region similarly to clinical disease, and were distributed evenly across prostate quadrants, with diagnostic disagreements largely resolved without affecting geographic comparisons.

Abstract

A world-wide comparative study of the frequency and characteristics of latent carcinoma of the prostate was undertaken in seven areas, using standardized methods and "blind" microscopic evaluation in order to reduce selection and observer bias. The morphological features of 350 latent carcinomas found in 1,327 prostates were examined. Two Chinese populations, from Hong Kong and Singapore, showed a low frequency of latent carcinoma in comparison with western Europeans in Sweden and the Federal Republic of Germany and negroes from Jamaica; an intermediate position was found for Israelis and black Ugandans. The frequency of small latent carcinomas was about 12% in all the areas investigated and did not vary with age. Rates for larger latent carcinomas increased sharply with age ans showed an area-to-area variation resembling that of clinical carcinoma of prostate. The small carcinomas were almost exclusively situated in the outer half of the prostate and latent carcinomas of all sizes were evenly distributed between the anterior and posterior halves of the prostate and the right and left sides of the outer prostatic shell. Certain disagreements in diagnosis were noted when the sections from each area were evaluated independently by a different pathologist. Most of these disagreements were resolved by re-reading the sections; their occurrence had no significant effect on the geographical comparisons.