Intermediate-risk prostate cancer treated with external beam radiotherapy (EBRT): A risk group with heterogeneous behavior.

145 Background: In men with intermediate-risk prostate cancer (IR-PC) treated with low dose EBRT, the addition of androgen deprivation therapy (ADT) prolongs overall survival. Zumsteg proposes a subdivision for de IR-PC group: favorable or unfavorable. Purpose: retrospective evaluation of EBRT efficacy according to IR-PC subgroups (favorable or unfavorable). Methods: From the institutional radiotherapy department database, from 2000 to 2011, 95 men with IR-PC were identified and subdivided as follows: Favorable Risk (FR) – Gleason 3+4 or less and positive prostate biopsies (ppb) not exceeding 50% and only one intermediate-risk factor excluding 4+3; Unfavorable risk (UR) – Gleason 4+3 or at least 2 intermediate-risk factors or at least one intermediate risk factor and ppb >50%. Results: 95 patients were included in the analysis, mean FUP 6.2 years. 32.6% (31) had >50% ppb, 14.7% (14) had Gleason 4+3, 38.9% (37) had 2 intermediate-risk factors. 42.1% (40) were FR and 57.9% (55) were UR. Median EBRT dose: 79...