Prediction of organ-confined disease by prostate-specific antigen nadir after neoadjuvant therapy

It is not clear whether or not serum prostate-specific antigen (PSA) levels after androgen deprivation prior to radical prostatectomy (neoadjuvant therapy) have any value in the prediction of the final pathologic stage.

We conducted a study on 49 patients who underwent retropubic radical prostatectomy following neoadjuvant therapy for clinical stage T1c, T2, and T3a prostate cancer. We evaluated progression-free survival based on the PSA failure rate and the predictive value of the PSA nadir after neoadjuvant therapy and other clinical factors to determine the most important predictor of organ confinement.

Of the 49 patients, 30 had organ-confined disease. Of 31 patients without adjuvant therapy after surgery, the PSA failure-free rates at 2 years were 81.6 and 34.3% in the subset of organ-confined disease and non-organ-confined disease, respectively (P= 0.0031). Of the 18 patients with adjuvant androgen deprivation therapy after surgery, the PSA failure-free rate at 2 years was 100% and 59.7% in patients with organ-confined disease and non-organ-confined disease, respectively. Baseline PSA (P=0.037), PSA nadir (P<0.0001) and PSA density (P=0.003) significantly correlated with organ confinement. Multivariate logistic regression analysis revealed that the PSA nadir was the only independent predictor of organ confinement (P = 0.044).

There was a trend that the patients with non organ-confined disease had a higher probability of PSA failure than did the patients with organ-confined disease. The PSA nadir after neoadjuvant therapy was the strongest predictor of organ confinement. The predictive value of the serum PSA nadir should be validated in well-designed larger population-based studies.