In an individual patient meta-analysis reported in the Journal of Clinical Oncology, Daniel E. Spratt, MD, and colleagues found that adjuvant androgen-deprivation therapy (ADT) was associated with improved progression free-survival vs neoadjuvant ADT in patients receiving radiotherapy for localized prostate cancer.
Study Details
The meta-analysis included a total of 1,605 patients from two phase III trials (Ottawa 0101 and NRG Oncology’s Radiation Therapy Oncology Group 9413) published through 2018 that evaluated the sequence, but not duration, of ADT with radiotherapy. Of these patients, 531 received neoadjuvant ADT and 534 received adjuvant ADT. The primary outcome measure was progression-free survival.
Daniel E. Spratt, MD
Key Findings
Median follow-up was 14.9 years. Progression-free survival at 15 years was 29% in the neoadjuvant group vs 36% in the adjuvant group (hazard ratio [HR] = 1.25, 95% confidence interval [CI] = 1.07–1.47, P = .01).
The 15-year cumulative incidence rates were 43% vs 33% (subdistribution HR = 1.37, 95% CI = 1.12–1.68, P = .002) for biochemical failure, 18% vs 12% (subdistribution HR = 1.40, 95% CI = 1.00–1.95, P = .04) for distant metastasis, and 20% vs 15% (subdistribution HR = 1.29, 95% CI = 0.95–1.75, P = .10) for prostate cancer–specific mortality (subdistribution HR = 1.39, 95% CI = 1.00–1.93, P = .053, among high-risk patients).
Hazard ratios were 1.17 (95% CI = 1.00–1.37, P = .050) for metastasis-free survival and 1.11 (95% CI = 0.95–1.30, P = .20) for overall survival (15-year rate = 34% vs 39%).
No differences between the neoadjuvant and adjuvant groups were observed in late grade ≥ 3 gastrointestinal (2% vs 3%, P = .33) or genitourinary toxicities (5% vs 5%, P = .76).
The investigators concluded, “The sequencing of ADT with prostate-directed radiotherapy has significant association with long-term progression-free survival and metastasis-free survival in localized prostate cancer. Our findings favor use of an adjuvant over a neoadjuvant approach, without any increase in long-term toxicity.”
Dr. Spratt, of the Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by the Prostate Cancer Foundation, Prostate Cancer SPORE, Department of Defense, and others. For full disclosures of the study authors, visit ascopubs.org.
