Clinical Edge

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Advanced prostate cancer: Extended androgen suppression lowers risk of distant progression, regardless of radiation dose 

Key clinical point: 18 months of androgen suppression (AS) significantly reduces the risk for distant progression compared with 6 months of AS in patients with advanced prostate cancer, independent of the radiation dose.

Major finding: 18 months versus 6 months of AS reduced the risk for distant disease progression by 30% (subhazard ratio, 0.70; P = .002), irrespective of the radiation dose.

Study details: 10-year follow-up of the TROG 03.04 RADAR trial which included 1,051 patients with locally advanced prostate cancer randomly assigned to 6- or 18-month AS with radiotherapy.

Disclosures: The study was supported by the National Health and Medical Research Council of Australia, the Goodfellow Foundation, Auckland (New Zealand), Cancer Standards Institute of New Zealand, Novartis Pharmaceuticals Australia, and AbbVie Pharmaceuticals Australia. James W. Denham received grant from Novartis Pharmaceuticals and nonfinancial support from AbbVie during the conduct of study. All remaining authors declared no competing interests.

Commentary

“The optimal approach to treatment of locally advanced prostate cancer is under constant study. A question of considerable importance refers to the length of time for androgen deprivation therapy (ADT), since side effects of ADT can be quite bothersome to patients. In the study by Joseph et al., men undergoing radiation were randomized to 6 versus 18 months ADT stratified by radiation dosing. Distant progression was significantly lower in the 18-month ADT cohort, independent of radiation dose. However, radiation was not randomly allocated, potentially biasing the results. While this study supports potentially longer ADT courses, further studies to find optimal radiation dose plus ADT schedules would be helpful to guide treatments for these patients.”

Mark Klein, MD

Citation:

Joseph D et al. Int J Radiat Oncol Biol Phys. 2020 Mar 15. doi: 10.1016/j.ijrobp.2019.11.415.