Clinical Utility of PCA3 Assay in Patients with Suspicious Prostate Cancer

Abstract

C ancer prostate is considered one of the major health problems as it is the second most common malignancy in men and a leading cause of cancer-related deaths. Current screening techniques for PCa are based on serum PSA assay and DRE, whereas a decisive diagnosis of PCa is based on a prostate biopsy. The use of serum PSA has some well-recognized limitations, such as its low specificity. Thus, patients are often subjected to unnecessary prostate biopsies especially in the so-called gray zone (PSA between 4–10 ng/mL). Thus, there is a need for further markers that can aid the clinician in determining which patients may benefit from undergoing prostate biopsy. The aim of this study was to evaluate the clinical utility of PCA3 assay in diagnosis of PCa and to assess its role in guiding initial biopsy decisions. Furthermore, PCA3 results were correlated with markers of tumor aggressiveness. This study was conducted on fifty patients selected from the Urology Department at Ain Shams University Hospitals with an indication for prostate biopsy because of an elevated tPSA level &/or a suspicious DRE. Urine samples from all participants were collected for PCA3 assay via RT-PCR after an attentive DRE. Blood samples were also collected for serum total and free PSA assay. TRUS- guided biopsy was then done and according to its results, participants were further classified into two subgroups: positive and negative biopsy groups. PCA3 has shown potential as a marker that is both more sensitive and specific to diagnosis of prostate cancer than the traditionally known markers namely tPSA and f/t PSA ratio. The median PCA3 score was significantly higher in men with positive biopsy vs those with a negative one. In addition, the diagnostic performance of PCA3 out-performed both tPSA and f/tPSA ratio in discriminating patients with positive prostate cancer from those with negative biopsy results. Our ROC curve analysis showed that PCA3 had the highest AUC compared to tPSA and f/tPSA.