Positive predictive value of high-grade prostatic intraepithelial neoplasia in initial core needle biopsies of prostate adenocarcinoma--a study with complete sampling of hemi-prostates with corresponding negative biopsy findings.

OBJECTIVES

High-grade prostatic intraepithelial neoplasia (HGPIN) is a putative premalignant lesion of prostate adenocarcinoma (PCa). The significance of isolated HGPIN in initial biopsy cores as a marker of PCa in repeat biopsies has been extensively investigated, but little is known of the true occurrence of PCa in this setting, because repeat biopsies can miss the focus of cancer. In this study, a hemi-prostate model was used to define the true positive predictive value of HGPIN in core biopsies in predicting PCa.

METHODS

From 132 consecutive resected prostate specimens, 70 hemi-prostates with all corresponding biopsy cores negative for PCa were thoroughly examined.

RESULTS

Of the 70 hemi-prostates, 38 had PCa (including 8 with clinically significant PCa), and 11 had HGPIN. In the group of 38 hemi-prostate with PCa, 7 were associated with HGPIN-positive biopsies. No statistically significant difference was found between the hemi-prostates with or without PCa, regarding the presence, microscopic pattern, or multiple core involvement of HGPIN in the biopsies. The positive predictive value of HGPIN in predicting for clinically significant PCa was 27%, the negative predictive value was 87%, the sensitivity was 38%, and the specificity was 91% (P = 0.04, statistically significant). In addition, the positive predictive value of multiple cores with HGPIN in predicting for clinically significant PCa was 75% (negative predictive value 92%).

CONCLUSIONS

The results of the present study have failed to support HGPIN as a statistically significant predictor for the occurrence of PCa. More importantly, however, HGPIN and multiple core involvement did seem to be a useful marker for clinically significant PCa.