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

Objective. To assess the utility of the nested reverse transcription-polyme rase chain reaction (RT-PCR) method for measuring prostate specific membran e 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 patien ts who subsequently underwent radical prostatestomy. The accuracy of the RT -PCR assays in predicting PSA failure was compared with those for the preop erative 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. B iochemical recurrence was defined as a serum PSA level of greater than or e qual to 0.4 ng/mL. Results. Statistical analysis indicated that the nested RT-PCR assay for PS M was the most accurate preoperative predictor of potential surgical failur e (PCR-PSM, P < 0.001; PCR-PSA, P = 0.018; serum PSA level, P = 0.149; Glea son score P = 0.388, by Fisher's exact probability test). Biochemical recur rence was evaluated in relation to these methods during a mean (range) foll ow-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) develop ed biochemical recurrence. The Kaplan-Meier recurrence-free actuarial proba bility curves differed significantly between patients with positive and tho se with negative results for the preoperative nested RT-PCR for PSM (P < 0. 01, generalized Wilcoxon's test). The nested RT-PCR for PSA, preoperative s erum PSA value and Gleason score were not significant predictors of biochem ical recurrence (P = 0.16, 0.12 and 0.24, respectively). Conclusions The nested RT-PCR for PSM was the best preoperative predictor o f biochemical recurrence among the factors examined.