10-Year Results of a Phase III Randomized Trial of High-Dose Radiotherapy and Risk-Adapted Androgen Deprivation in Localized Prostate Cancer.

Purpose/Objective(s) The optimal duration of androgen deprivation (AD) combined with high-dose radiotherapy (HDRT) in prostate cancer remains a matter of controversy. We did a phase 3 trial designed to determine whether long-term AD (LTAD) is superior to short-term AD (STAD) when combined with HDRT. In this report, we present the 10-year survival results. The hypothesis is that long-term AD (LTAD) compared to short-term AD (STAD) improves overall survival among high-risk patients receiving HDRT. Materials/Methods This open-label, phase 3 randomized controlled trial, recruited patients from ten university hospitals throughout Spain. Eligibility included patients with cT1c-T3aN0M0 adenocarcinoma of prostate with intermediate and high-risk factors according to NCCN criteria and PSA less than 100 ng/ml. All patients received 4 months of neoadjuvant and concomitant AD (STAD) + HDRT (median radiation dose 78 Gy) before randomization to adjuvant goserelin for two years (LTAD). Stratification was performed according to risk group (intermediate risk [IR] versus high risk [HR]). Study endpoints included overall survival (OS), metastasis free survival (MFS), disease free survival (DFS) and biochemical-disease free survival (bDFS). Survival analyses were done with Kaplan-Meier (KM) curves. Fine & Gray (FG FG FG F&G P = 0.057, HR, 1.12, 95% CI, 0.46 to 2.73). Only 11 patients died from PCa, all of them in the high-risk subgroup. Conclusion Long term results failed to show a significant benefit with LTAD compared to STAD in patients treated with HDRT. The subgroup of patients with high-risk PCa treated with LTAD had a non-significant improvement in bDFS, MFS and OS compared with STAD. The relatively small simple size, a low number of events and an effective salvage treatment could be responsible for the lack of a statistical significance. The trial is registered at ClinicalTrials.gov, number NCT 02175212.