Short-Term Neoadjuvant Androgen Deprivation Therapy and External-Beam Radiotherapy for Locally Advanced Prostate Cancer: Long-Term Results of RTOG 8610

Abstract

Purpose Radiation Therapy Oncology Group (RTOG) 8610 was the first phase III randomized trial to evaluate neoadjuvant androgen deprivation therapy (ADT) in combination with external-beam radiotherapy (EBRT) in men with locally advanced prostate cancer. This report summarizes long-term follow-up results. Materials and Methods Between 1987 and 1991, 456 assessable patients (median age, 70 years) were enrolled. Eligible patients had bulky (5 × 5 cm) tumors (T2-4) with or without pelvic lymph node involvement according to the 1988 American Joint Committee on Cancer TNM staging system. Patients received combined ADT that consisted of goserelin 3.6 mg every 4 weeks and flutamide 250 mg tid for 2 months before and concurrent with EBRT, or they received EBRT alone. Study end points included overall survival (OS), disease-specific mortality (DSM), distant metastasis (DM), disease-free survival (DFS), and biochemical failure (BF). Results Ten-year OS estimates (43% v 34%) and median survival times (8.7 v 7.3 years) favored ADT and EBRT, respectively; however, these differences did not reach statistical significance (P = .12). There was a statistically significant improvement in 10-year DSM (23% v 36%; P = .01), DM (35% v 47%; P = .006), DFS (11% v 3%; P < .0001), and BF (65% v 80%; P < .0001) with the addition of ADT, but no differences were observed in the risk of fatal cardiac events. Conclusion The addition of 4 months of ADT to EBRT appears to have a dramatic impact on clinically meaningful end points in men with locally advanced disease with no statistically significant impact on the risk of fatal cardiac events.