Adding 6 months of adjuvant androgen suppression to radiotherapy improves biochemical and clinical disease-free survival (DFS) of patients with intermediate-risk and high-risk cT1b-c to cT2a prostate cancer, a study published in the Journal of Clinical Oncology has shown.1
Because up to 30% of patients who receive radiation for intermediate-risk or high-risk localized prostate cancer relapse biochemically within 5 years, researchers sought to evaluate whether adding androgen suppression for a short duration to primary radiotherapy can improve biochemical disease-free survival in patients with intermediate-risk or high-risk localized disease.
For the study, researchers enrolled 819 patients with stage cT1b-c and a prostate-specific antigen (PSA) 10 ng/mL or higher or Gleason score of 7 or higher, or stage cT2a prostate cancer. Patients were only eligible if they had no involvement of pelvic lymph nodes or clinical evidence of metastasis, and had a PSA 50 ng/mL or less. Of those, 74.8% were intermediate risk and 24.8% were high risk.
Participants were randomly assigned 1:1 to receive radiotherapy or radiotherapy plus 2 depot injections of a luteinizing hormone–releasing hormone agonist on day 1 every 3 months as 6 months of androgen suppression.
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Results showed that after a median follow-up of 7.2 years, radiotherapy plus androgen suppression significantly improved biochemical disease-free survival (HR, 0.52; 95% CI: 0.41-0.66; P<.001). Researchers found that adding androgen suppression also improved clinical progression-free survival (Hr, 0.63; 95% CI: 0.48-0.84; P=.001).
Of note, overall survival data are not yet mature.
1. Bolla M, Maingon P, Carrie C, et al. Short androgen suppression and radiation dose escalation for intermediate- and high-risk localized prostate cancer: results of EORTC trial 22991 [published online ahead of print March 14, 2016]. J Clin Oncol. doi:10.1200/JCO.2015.64.8055.