PROSTATE-SPECIFIC ANTIGEN PROGRESSION RATES AFTER RADICAL PROSTATECTOMY OR RADIATION-THERAPY FOR LOCALIZED PROSTATE-CANCER

Background. The purpose of the study was to determine whether a differ ence is noted in the rate of prostate specific antigen (PSA) elevation after radical prostatectomy or radiation therapy for localized prosta te cancer. Methods. PSA doubling times were calculated by linear regre ssion analysis in 50 patients who had been treated by radical prostate ctomy and who had three or more increasing PSA levels and in 55 patien ts who had been treated with radiation therapy and who had three or mo re increasing PSA levels. Results. No significant difference was noted in the mean PSA doubling times in the two patient groups when stratif ied by the site of tumor recurrence or by pretreatment tumor stage, tu ner Conclusions. Because the PSA doubling time probably parallels the tumor growth rate, these data suggest that the malignant potentials of recurrent tumor after radical prostatectomy and after radiation thera py are equivalent.