PSA levels and the rate of positive surgical margins in radical prostatectomy specimens preceded by androgen blockade in clinical B 2 (T2bNxMo) prostate cancer

Abstract

Objectives Neoadjuvant hormonal therapy reduces positive margins in patients undergoing radical prostatectomy. All patients experience a decrease in serum prostate specific antigen (PSA), but not always to a level that is nondetectable. The results of several prospective, randomized trials indicate that the incidence of positive margins decreases with the use of androgen deprivation prior to radical prostatectomy. It has been suggested that a greater decline in PSA levels would result in fewer positive margins. In a recent US trial of patients with T2bNxMO prostate cancer, we reported that 18% of patients randomized to receive 3 months of leuprolide acetate and flutamide had positive margins, compared to 48% of those who had radical prostatectomy alone ( P <0.001). We correlated the PSA levels prior to and following androgen deprivation and the presence of a positive margin following radical prostatectomy (RP). Methods One hundred and thirty-seven of 149 patients randomized to receive presurgery androgen deprivation (AD) underwent radical prostatectomy. Of these, 135 had a PSA level obtained both prior to androgen deprivation and prior to surgery. We analyzed the percent positive margins in patients whose PSA values became undetectable and in those whose values remained above 0.1 ng/mL despite androgen deprivation. Results Eight of 43 patients (19%) with a nadir PSA ≤0.1 ng/mL had a positive surgical margin and 16/92 (17%) with a nadir PSA >0.1 ng/mL had tumor at the margin. There were no statistical differences in these two groups ( P = 1.0 by Fisher's Exact Test [two-tailed], and the Pearson correlation was −0.015). Conclusions There was no correlation between an undetectable PSA and a PSA >0.1 ng/mL and the presence of tumor at the margin when 3 months of AD was given prior to RP. It is possible that longer periods of AD prior to RP will reduce PSA to an undetectable level in a higher percent of patients. However, these data suggest that an undetectable level will not result in less positive margins.