Prognostic Significance of α-Methylacyl-CoA Racemase Among Men With High Grade Prostatic Intraepithelial Neoplasia in Prostate Biopsies

PurposeSerum prostate specific antigen screening has increased the number of prostate biopsies performed increasing the number of patients with high grade prostatic intraepithelial neoplasia. The criteria for re-biopsy are not standardized but may be refined by the identification of novel biomarkers demonstrating prognostic significance. Alpha-methylacyl-CoA racemase is a robust marker of prostate cancer and is expressed in a subset of high grade prostatic intraepithelial neoplasia. This study evaluates the prognostic significance of α-methylacyl-coA racemase positive high grade prostatic intraepithelial neoplasia glands in prostate biopsies.Materials and MethodsImmunohistochemical staining with α-methylacyl-coA racemase and p63 was examined in a selected group of 62 patients with a diagnosis of high grade prostatic intraepithelial neoplasia on initial prostate biopsy, of which on repeat biopsy 32 had no carcinoma and 30 had prostate cancer. There was no significant difference in age, number of cores sampled or prostate specific antigen history between the 2 outcome groups (ANOVA p >0.9). High grade prostatic intraepithelial neoplasia glands in each case were evaluated for α-methylacyl-coA racemase and p63.ResultsReactivity for α-methylacyl-coA racemase was found in 27 of the 62 cases examined. Fisher’s exact analysis revealed that patients with at least 1 α-methylacyl-coA racemase positive high grade prostatic intraepithelial neoplasia gland were 5.2 times more likely to have a subsequent diagnosis of prostate cancer on repeat biopsy than those without any α-methylacyl-coA racemase positive high grade prostatic intraepithelial neoplasia glands (p = 0.0044). No correlation was found between α-methylacyl-coA racemase positivity and any other clinical variable.ConclusionsThis is the first study to our knowledge to illustrate that α-methylacyl-coA racemase reactivity in high grade prostatic intraepithelial neoplasia may be useful to refine re-biopsy criteria and assist in clinical management decisions.