Is there a "curative" role of radiotherapy for clinically localized hormone refractory prostate cancer?

Abstract

Whether definitive radiotherapy (RT) is still an option for patients with clinically prostate-confined prostate cancer treated with androgen deprivation (AD) alone who develop a rising prostate-specific antigen (PSA) is not clear. In this retrospective series, we report the outcome of 29 such patients treated with "curative" radiotherapy at our institution between 1991 and 2000. At initial diagnosis, all patients had evidence of prostate-confined disease and for several reasons underwent AD alone. Afterward all patients developed rising PSA, but again, without clinical evidence of distant/pelvic node disease. All underwent RT with curative intent up to 70 Gy (66 to 76 Gy). Median follow-up after radiotherapy is 33.1 month (range: 7-134.2 months). For living patients, minimum and median follow-ups are 30.4 and 55.4 months, respectively. Twenty-three patients (79%) developed overt clinical disease, most of which (19/23, 83%) involved distant sites, whereas isolated locoregional failure was observed in only 4 patients (4/23, 17%). The estimates of locoregional control rate (LRC), actuarial incidence of distant metastases, and overall survival at 5 years are 89 +/- 7%, 68 +/- 9%, and 28 +/- 9%, respectively. Although we were unable to find any predictor of LRC at univariate analysis, patients with low Gleason score at diagnosis, lower PSA at RT, lower risk category and advanced age were less likely to develop distant disease. RT has a palliative role, because most patients with still presumed localized hormone refractory prostate cancer will develop distant metastases. A subset of patients, those with more differentiated tumor at diagnosis and with pre-RT PSA less than 20 ng/mL, might be considered for a more aggressive locoregional approach.