ASCO 2017: Duration of androgen deprivation therapy in high risk prostate cancer: Final results of a randomized phase III trial

Chicago, IL ( Long-term androgen deprivation therapy (ADT) combined with radiotherapy (RT) is a standard treatment for patients with high-risk prostate cancer (HRPC). However, the optimal duration of ADT is still not defined. Dr. Nabid presented a randomized trial (Clinical, #NCT00223171) aiming to compare outcomes of RT combined with either 36 or 18 months of ADT.

Patients with localized HRPC were randomized to pelvic and prostate RT combined with 36 (arm 1) or 18 months (arm 2) of ADT. Inclusion criteria included T3-T4 disease, PSA >20 ng/ml, Gleason score >7, age <= 80 and Zubrod 0-1, with normal hepatic function and no regional or metastatic disease. Overall survival (OS), disease specific survival (DSS), and quality of life (QoL) were primary end points. Overall 630 patients were randomized, 310 to arm 1 and 320 to arm 2.

Results demonstrated a median follow-up was 9.4 years, during which 290 patients had died (147 arm 1 vs. 143 arm 2). The 10-year OS rate was 62.4% (95% confidence interval [CI] 56.4%, 67.8%) for arm 1 and 62.0% (95% CI 56.1%, 67.3%) for arm 2 (p = 0.8412) with a global hazard ratio (HR) of 1.024 (95% CI 0.813-1.289, p = 0.8411). In univariate and multivariable analysis increasing age and Gleason score above 7 were predictors of decreased OS. QoL analysis showed a significant difference (p < 0.001) in 6 scales and 13 items favoring the shorter ADT treatment.

In summary, in localized HRPC patients, ADT combined with RT can be safely reduced from 36 to 18 months without compromising oncologic outcomes or QoL. Dr. Nabid concluded that 18 months of ADT should represent a new standard of care in HRPC.

Presented By: Abdenour Nabid, Centre Hospitalier Régional Universitaire, Sherbrooke, QC, Canada

Written By: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre
Twitter: @GoldbergHanan

at the 2017 ASCO Annual Meeting - June 2 - 6, 2017 – Chicago, Illinois, USA