Individual Patient Data Meta-Analysis of Randomized Trials in Cancer of the Prostate (MARCAP) Consortium: Impact of Androgen Deprivation Therapy Use and Duration With Definitive Radiotherapy for Localized Prostate Cancer.

Abstract

PURPOSE/OBJECTIVE(S)\nTo conduct the first global individual patient data (IPD) meta-analysis of randomized trials to assess the impact of androgen deprivation therapy (ADT) use and duration with definitive radiotherapy (RT) in localized prostate cancer.\n\n\nMATERIALS/METHODS\nThe MARCAP Consortium was formed from international trial groups (NRG/RTOG, EORTC, TROG, DART/GICOR, and ICORG). IPD for 10,131 patients enrolled across 11 RT trials were available for three pre-specified meta-analyses: addition of ADT to RT (5 trials; n\u202f=\u202f4736), addition of long-term adjuvant ADT (12-30 months) to short-term ADT (4 trials; n\u202f=\u202f3674), and addition of longer neoadjuvant ADT (3-7 months) to short-term ADT (3 trials; n\u202f=\u202f2213). The primary endpoint of all meta-analyses was overall survival (OS), with metastasis-free survival (MFS) as a secondary endpoint. Interaction tests between treatment and receipt of dose-escalated RT (≥74 Gy in 2 Gy fractions) were performed.\n\n\nRESULTS\nAfter a median follow-up of 12.0 years, the addition of ADT to RT improved 12-year OS (absolute 7.2%, HR 0.87, 95% CI 0.8-0.95) and 12-year MFS (absolute 8.3%, HR 0.85, 95% CI 0.79-0.92). After a median follow-up of 10.9 years, prolongation of adjuvant ADT improved 12-year OS (absolute 6.3%, HR 0.86, 95% CI 0.78-0.94) and 12-year MFS (absolute 6.3%, HR 0.83, 95% CI 0.77-0.90). After a median follow-up of 10.3 years, prolongation of neoadjuvant ADT was not associated with a significant benefit in any endpoint (MFS HR 0.95, 95% CI 0.83-1.09; OS HR 0.94, 95% CI 0.82-1.09). On subgroup analysis, there was no evidence of a treatment effect interaction between RT dose and ADT use (OS P-interaction 0.59) or adjuvant ADT prolongation (OS P-interaction 0.13). In the setting of dose-escalated RT, adjuvant ADT prolongation significantly improved OS (HR 0.70, 95% CI 0.53-0.92).\n\n\nCONCLUSION\nThis study represents the strongest evidence to support ADT use and prolongation of adjuvant ADT to at least 18 months in localized prostate cancer in conjunction with definitive RT. The relative benefit of ADT use and adjuvant ADT prolongation was consistent irrespective of RT dose-escalation. In contrast, prolongation of neoadjuvant ADT beyond 2 months did not improve survival outcomes and should not routinely be employed.