The Role of PCA3 Testing in Patients with a Raised Prostate-Specific Antigen Level After Greenlight Photoselective Vaporization of the Prostate

Background and Purpose: Greenlight (R) photoselective vaporization of the prostate (PVP) is an effective method for treating men with lower urinary tract symptoms. A rise in prostate specific antigen (PSA) levels, however, may be noticed in some patients during follow-up. The aim of this study was to determine whether the prostate cancer gene 3 (PCA3) urinary test would help identify patients who were in need of a prostate biopsy. Patients and Methods: The PSA of all patients undergoing PVP were analyzed. Patients with an elevated (above reference range) or rising PSA level (defined as > 0.75 ng/mL/year if the PSA was between 4.1 and 10 or a doubling time of less than 2 years) were offered a transrectal ultrasonography (TRUS) guided prostate biopsy. Before the biopsy procedure, all patients had a PCA3 test. The relationships between PSA, PCA3, and TRUS prostate biopsy findings were analyzed to determine sensitivity and specificity for the PCA3 test in this setting. Results: 50 patients were identified. The mean age was 69.97 (range 57-83) years. The mean PSA level was 10.1 ng/mL (range 3.03-44.2 ng/mL). Six patients were found to have prostate cancer. Of those, five patients had a positive PCA3 test. One patient had a negative PCA3 test but positive biopsy findings. This gives a sensitivity of 83.3%, and a positive predictive value of 21.7%. The negative predictive value was 96%. Conclusion: The results suggest that a negative PCA3 test in our group of patients is a good predictor of negative biopsy results. The low positive predictive value may be an artefact of the group size. This will need further investigation and greater patient numbers to determine.