Purpose: We report a prospective study examining the ability of preoperative nested reverse transcriptase polymerase chain reaction (RT-PCR) for prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSM) to predict pathologic stage and biochemical recurrence in patients with clinically localized prostate cancer treated with radical prostatectomy.
Patients and methods: One hundred forty-one patients were entered onto the study. Preoperative evaluation included clinical T stage, serum PSA, biopsy Gleason score, and serum RT-PCR for PSA/PSM. Univariate and multivariate logistic regression models, Kaplan-Meier estimates, and Cox proportional hazards modeling were used to identify predictors of pathologic stage and biochemical failure.
Results: Seventy-three patients (51.8%) were RT-PCR positive for PSA, PSM, or both. In the multivariate logistic regression model, only initial PSA was an independent predictor of pathologic stage as defined by organ-confined disease (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.00 to 1.13; P =.026) or organ-/specimen-confined disease (OR, 1.09; 95% CI, 1.02 to 1.16; P =.009). Overall Kaplan-Meier biochemical relapse-free survival (bRFS) was 85% at 59 months. Multivariate analysis of predictors for bRFS with the Cox proportional hazards model indicated that only initial PSA (OR, 1.05; 95% CI, 1.02 to 1.09; P =.004) and biopsy Gleason score (OR, 3.57; 95% CI, 1.37 to 9.58; P =.009) were independent predictors of biochemical failure. RT-PCR status did not predict pathologic stage or biochemical failure. Repeat analysis excluding 27 patients who received preoperative androgen-deprivation therapy did not change the results.
Conclusion: Combined nested RT-PCR for PSA and PSM is not an independent predictor of pathologic stage or biochemical failure in patients with localized prostate cancer undergoing radical prostatectomy. This assay has no clinical utility in this patient population.