Frequency of high-grade prostatic intraepithelial neoplasia in Mexican population.

Background: High-grade intraepithelial neoplasia (HGPIN) is the only lesion regarded as precursor of prostatic carcinoma, though its frequency is unknown in many countries. Here we studied the frequency of HGPIN in a population with high grade frequency of prostatic carcinoma.
Material and Methods: A total of 486 cases of sextant prostatic biopsies performed from January 2001 to January 2006 were reviewed. These included 280 biopsies from patients belonging to an urban population, with medium or high socioeconomic status, from two hospitals in Mexico City. For comparison, 206 cases from the Regional Hospital of Tabasco located in the tropical zone of the country were included. This hospital receives patients from a rural population with low income and socioeconomic status.
Results: Of the total 486 cases, 162 (33.33%) cases were diagnosed as prostatic carcinoma and 319 (65.64%) as benign conditions. Only in five (1.03%) biopsies was HGPIN found. Three of these patients were from Mexico City, and two from the Regional Hospital of Tabasco.
Conclusions: Even when our results were obtained only in three hospitals, they suggest that a low frequency of HGPIN on needle prostate biopsies does not necessarily mean a low frequency of prostatic carcinoma in the same population. The reason for such a disparity could be related to a reduced extension of HGPIN areas in the prostate gland. In populations with low frequency of HGPIN and high incidence of prostatic carcinoma, perhaps more biopsy cores should be obtained in order to minimize false negative results for premalignant lesions or early adenocarcinoma.