Clinical evaluation of prostate cancer gene 3 score in diagnosis among Chinese men with prostate cancer and benign prostatic hyperplasia

Background: Prostate cancer is the second most common diagnosed cancer in men. Due to the low specificity of current diagnosis methods for detecting prostate cancer, identification of new biomarkers is highly desirable. The study was conducted to determine the clinical utility of the prostate cancer gene 3 (PCA3) assay to predict biopsy-detected cancers in Chinese men. Methods: The study included men who had a biopsy at The Affiliated Sixth People's Hospital of Shanghai Jiao Tong University from January 2013 to December 2013. Formalin-fixed, paraffin-embedded tissue blocks were used to test PCA3 and prostate-specific antigen (PSA) mRNA. The diagnostic accuracy of the PCA3 score for predicting a positive biopsy outcome was studied using sensitivity and specificity, and it was compared with PSA. Results: The probability of a positive biopsy increased with increasing PCA3 scores. The mean PCA3 score was significantly higher in men with prostate cancer (198.03, 95 % confidence interval [CI] 74.79-321.27) vs benign prostatic hyperplasia (BPH) (84.31, 95 % CI 6.47-162.15, P < 0.01). The PCA3 score (cutoff 35) had a sensitivity of 85.7 % and specificity of 62.5 %. Receiver operating characteristic analysis showed higher areas under the ROC curve for the PCA3 score vs PSA, but without statistical significance. Conclusions: Increased PCA3 in biopsy tissue correlated with prostate cancer and the PCA3 assay may improve the diagnosis efficacy as the PCA3 score being independent of PSA level. The diagnostic significance of urinary PCA3 testing should be explored in future study to determine the prediction value in guiding biopsy decision as the clinical relevance of current study was limited for PCA3 testing based on biopsy tissue in a limited number of Chinese men.