PROSTATE SPECIFIC ANTIGEN KINETICS AT TUMOR RECURRENCE AFTER RADICAL PROSTATECTOMY DO NOT SUGGEST A WORSE DISEASE PROGNOSIS IN BLACK MEN

Abstract

It has been shown that black men with clinically localized prostate adenocarcinoma treated with radical prostatectomy have poorer disease-free and disease specific survival than white men with similar tumors. These findings suggest that a potentially more aggressive variant of prostate cancer exists in black men. Because prostate specific antigen (PSA) velocity at tumor recurrence is a good indicator of disease aggressiveness, we determine whether there was evidence that PSA velocity at biochemical recurrence after radical prostatectomy is faster in black men. Our retrospective data search at 2 university centers resulted in 127 white and 37 black men with clinical stage cT1 to 2 prostate adenocarcinoma who underwent radical prostatectomy between 1990 and 1994 and had evidence of biochemical recurrence (PSA greater than 0.2 ng./ml.) on followup available for analysis. No neoadjuvant or adjuvant treatments were given before or after radical prostatectomy, and all PSA relapses and subsequent treatments were recorded. PSA velocity modeling was performed in patients before any form of treatment for PSA failure. Preoperative PSA, Gleason score and pathological stage were also included in the model to assess the impact on PSA velocity after recurrence. Our data suggested that PSA velocity at tumor recurrence was related to preoperative PSA on a continuous scale (p = 0.063). However, in our analysis there was little evidence that race had any effect on PSA velocity at tumor recurrence in our patient cohort (p = 0.58). Likewise, little difference in PSA velocity was seen in regard to Gleason score (p = 0.89) or pathological stage (p = 0.23) in these patients. With data on 37 black men available for analysis it was likely that only large or extreme trends could be detected. Results could be used to estimate required sample sizes for assessment of less extreme trends. Our data on tumor growth rate at recurrence, as reflected by PSA velocity kinetics, do not support the hypothesis that prostate tumors in black men are necessarily more aggressive due to enhanced growth. Further studies comparing the molecular and biological differences between prostate cancers in black and white males are needed to clarify reasons for the apparent differences in initial presentation, as compared to that at tumor recurrence in these 2 groups.