For men with localized prostate cancer, xxxx demonstrated that adding short-term Androgen deprivation therapy (ADT) to radiotherapy (RT) improved the primary endpoint of overall-survival (OS) and also improved disease-specific-mortality (DSM), biochemical-failure (BF), local-progression (LP) and freedom from distant-metastases (DM). This study was performed to determine whether the short-term ADT continued to improve OS, DSM, BF, and freedom from DM with longer follow-up.
From 1994-2001, xxxx randomized 2028 men from 212 North American institutions with T1b-T2b, N0 prostate adenocarcinoma and PSA≤20ng/mL to RT-alone or RT plus short-term ADT. Patients were stratified by PSA, tumor-grade, and surgical versus clinical nodal staging. ADT was flutamide with either goserelin or leuprolide for 4 months. Prostate RT (66.6 Gy) was started after two months. OS was calculated at the date of death from any cause or at last follow-up. Secondary endpoints were DSM, BF, LP and DM. Acute and late toxic effects were assessed using **** toxicity scales.
Median follow-up in surviving patients was 14.8 years (0.16-21.98). 10-year and 18-year OS was 56% and 23% with RT-alone versus 63% and 23% with combined-therapy (HR 0.94, 95%CI: 0.85-1.05, p=0.94). The hazards were not proportional (p=0.003). Estimated restricted-mean-survival-time at 18 years was 11.8 years (95%CI: 11.4-12.1) with combined-therapy versus 11.3 years with RT-alone (95%CI: 10.9-11.6, p=0.05). 10-year and 18-year DSM was 7% and 14% with RT-alone versus 3% and 8% with combined-therapy (HR=0.56, 95%CI: 0.41-0.75, p<0.01). DM and BF favored combined-therapy at 18 years. Rates of late grade ≥3 hepatic, gastrointestinal and genitourinary toxicity were ≤1%, 3%, 8% with combined-therapy versus ≤1%, 2%, 5% with RT-alone.
Further follow-up demonstrates that OS converges at approximately 15 years, by which point the administration of 4 months of ADT had conferred an estimated additional 6 months of life.

Copyright © 2021. Published by Elsevier Inc.

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