Long-term outcomes of androgen deprivation therapy in prostate cancer among Japanese men over 80 years old

This study aimed to analyze the survival rate and to examine the risk of death from prostate cancer when accounting for competing risk of death, in men aged ≥80 y treated with primary androgen deprivation therapy (ADT). Data of patients with prostate cancer who had received ADT were extracted from a nationwide community-based database established by the Japan Study Group for Prostate Cancer. Prognostic variables, including progression-free survival, cancer-specific survival, overall survival, and death rates were compared between men stratified by prostate cancer risk. Overall, 4760 patients older than 80 y were included. The proportion of low-, intermediate-, high-, or very high-risk, regional, and metastatic prostate cancer among super-elderly men was 9.5%, 14.6%, 48.8%, 9.0%, 3.2%, and 24.9%, respectively. Survival rates decreased with increasing risk stratification. The cumulative 5-y death rate by prostate cancer for low-, intermediate-, high-, or very high-risk, regional, and metastatic prostate cancer, was 0.92% (95% confidence interval [CI]: 0.2%-3.6%), 1.6% (95% CI: 0.8%-3.4%), 5.75% (95% CI: 4.25%-7.75%), 15.6% (95% CI: 11.6%-23.3%), 20.7% (95% CI: 13.1%-31.7%), and 36.9% (95% CI: 32.8%-41.4%), respectively. Our findings support that there is no need for immediate ADT for low- and intermediate-risk groups. Conversely, in high- or very high-risk, regional, and metastatic prostate cancer, more efforts for curative therapy and intensive therapy are needed in selected patients.