MORPHOMETRIC ANALYSIS AND CLINICAL FOLLOW-UP OF ISOLATED PROSTATIC INTRAEPITHELIAL NEOPLASIA IN NEEDLE-BIOPSY OF THE PROSTATE

Purpose: We evaluate the significance of grade and extent of isolated prostatic intraepithelial neoplasia in prostate needle biopsies as a p redictor of cancer on repeat biopsy. Materials and Methods: We reviewe d our experience with 58 men 50 years or older who had isolated prosta tic intraepithelial neoplasia on initial prostate needle biopsy during a prostate specific antigen (PSA) based screening trial for prostate cancer. All 58 men underwent repeat biopsy to follow the initial findi ngs of prostatic intraepithelial neoplasia. We assessed the relationsh ip of patient age, digital rectal examination, serum PSA concentration , PSA density, prostatic intraepithelial neoplasia grade, number of fo ci of neoplasia and linear extent of prostatic intraepithelial neoplas ia in the initial biopsy specimen to the finding of cancer on the repe at biopsy. We also compared the cancer detection rate in the 58 men wi th and 427 without prostatic intraepithelial neoplasia in the same scr eening trial. Results: Of 21 men with low grade and 37 with high grade prostatic intraepithelial neoplasia 4 (19%) and 19 (51%), respectivel y, had cancer on repeat biopsy (p<0.02), compared to 82 of 427 (19%) w ithout cancer or prostatic intraepithelial neoplasia on the initial bi opsy. High grade prostatic intraepithelial neoplasia was a significant predictor of malignancy on repeat biopsy (p<0.05). The number of foci of neoplasia and the linear extent of prostatic intraepithelial neopl asia on initial biopsy were not predictive of cancer on repeat biopsy. Conclusions: Our results demonstrate that the presence of high grade p rostatic intraepithelial neoplasia is a strong predictor of prostate c ancer in men with elevated serum PSA concentrations and they should be followed with repeat biopsy.