Is there a subset of patients with PSA >= 20 ng/ml who do well after conformal beam radiotherapy?

To determine if there is a subgroup of patients with pretreatment PSA great er than or equal to 20 ng/ml with a favorable outcome after external beam r adiation therapy. We analyzed retrospectively treatment outcomes of 129 pat ients with pretreatment PSA greater than or equal to 20 ng/ml treated in ou r department from 2/88-8/94. Median patient age was 70 years (range 51-89 y ears). Tumor stage was T1/T2ab in 68, T2c/T3 in 61 patients. Initial Gleaso n grade was < 7 in 82 and greater than or equal to 7 in 47 patients. Median PSA was 35 ng/ml (mean 45 ng/ml, range 20-191 ng/ml). Ninety-seven patient s received four-field conformal external beam radiation therapy. No patient received surgery or hormonal therapy prior to treatment. Median central ax is dose was 73 Gy (range 68-79 Gy). Covariates considered in univariate and multivariate analyses included central axis dose, pretreatment PSA, presen ce of perineural invasion, Gleason score, palpable tumor stage and patient age. bNED failure was defined as a PSA greater than or equal to 1.5 and ris ing on two consecutive determinations. Median follow up was 50 months (rang e 3-100 months). Overall bNED control for the entire patient population was 22% at five years. Of the covariates analyzed, dose (P < 0.01), stage (P < 0.01), Gleason Score (P < 0.01), and the presence of PM (P = 0.01) were si gnificant on multivariate analysis. Based on these results, patients could be stratified into two distinct groups. Group I consisted of 19 patients wi th favorable features including T1/T2ab disease, Gleason Score 2-6, no peri neural invasion treated to a dose > 73 Gy to the central axis. Patients in Group II had at least one of the above poor prognostic features or were tre ated to central axis doses < 73 Gy. The bNED control was significantly high er for patients in Group I than those in Group II (58% vs. 23%, P = 0.0027) . There appears to be a favorable subgroup of patients with PSA greater tha n or equal to 20 ng/ml where treating to doses over 73 Gy to the central ax is is warranted (four-year bNED rate of 58%). However, because of the small patient numbers, these results will need to be validated with longer follo w up. (C) 1999 Wiley-Liss, Inc.