Epidemiology of high-grade prostatic intraepithelial neoplasia

This review summarizes published data dealing with the prevalence of high-grade prostatic intraepithelial neoplasia (HGPIN) in a variety of prostate tissue samples. Additionally, we have attempted to document the relationship between HGPIN and the pathological parameters of prostate cancer in autopsy and radical prostatectomy specimens. Studies reporting the prevalence of HGPIN in needle biopsies, transurethral resection specimens and radical prostatectomy specimens, and those documenting the lesion in postmortem settings are compared. We also summarize studies in which the distribution and/or extent of HGPIN was correlated with prostate cancer stage, grade and volume. There is significant variation in the reported frequency of HGPIN, particularly in needle biopsy specimens, with a range of 0.8-23.9%. The factors responsible for these discrepancies include the population studied, the limited sample size that needle biopsies represent, diagnostic inconsistencies and, possibly, tissue preparation/staining variables. Because of the important implications a diagnosis of HGPIN carries, there is a pressing need to achieve greater consistency in diagnosing and reporting the lesion. Better targeted educational efforts, including teaching courses, websites with illustrations and the possibility of teleconsultations, are among possible means to attain this goal. Better documentation of the evolution of HGPIN to cancer through clinical follow-up is also recommended.