Preoperative nested reverse transcription‐polymerase chain reaction for prostate specific membrane antigen predicts biochemical recurrence after radical prostatectomy

Abstract

Objective To assess the utility of the nested reverse transcription‐polymerase chain reaction (RT‐PCR) method for measuring prostate specific membrane antigen (PSM) and prostate specific antigen (PSA) in predicting serum PSA recurrence after radical prostatectomy. Patients and methods Nested RT‐PCRs for PSM and PSA were used in 40 patients who subsequently underwent radical prostatectomy. The accuracy of the RT‐PCR assays in predicting PSA failure was compared with those for the preoperative serum PSA level, Gleason score and final pathological staging. The patients were monitored using a PSA assay (Tandem‐R, Hybritech, San Diego, CA) at 3 weeks after radical prostatectomy and every 2 months thereafter. Biochemical recurrence was defined as a serum PSA level of ≥0.4 ng/mL. Results Statistical analysis indicated that the nested RT‐PCR assay for PSM was the most accurate preoperative predictor of potential surgical failure (PCR‐PSM, PP=0.018; serum PSA level, P=0.149; Gleason score P=0.388, by Fisher’s exact probability test). Biochemical recurrence was evaluated in relation to these methods during a mean (range) follow‐up of 16.7 (6–35) months. Of the 40 patients, eight (20%, one with organ‐confined cancer and seven with extraprostatic extension of cancer) developed biochemical recurrence. The Kaplan–Meier recurrence‐free actuarial probability curves differed significantly between patients with positive and those with negative results for the preoperative nested RT‐PCR for PSM (PP=0.16, 0.12 and 0.24, respectively). Conclusions The nested RT‐PCR for PSM was the best preoperative predictor of biochemical recurrence among the factors examined.