Use of androgen deprivation therapy for metastatic prostate cancer in older men.

Abstract

To assess factors associated with early or delayed androgen deprivation therapy (ADT) among men diagnosed with metastatic prostate cancer, and to assess the relationship between ADT and overall survival, as there is uncertainty about the ideal timing for initiating ADT in men with metastatic prostate cancer. We studied a population-based cohort of American men aged >or=66 years diagnosed with metastatic prostate cancer during 1992-2002 and followed to 2003. We assessed the receipt of ADT early (<or=4 months from diagnosis), delayed (>4 months), or not at all, using multinomial logistic regression to identify factors associated with treatment, and Cox proportional-hazard models to assess whether treatment was associated with survival. Overall, 69.5% of men received early ADT and 7.3% delayed. Adjusted rates of early ADT were lower for black than white men (58.3% vs 71.0%), and of delayed ADT were higher for black than white men (12.7% vs 6.2%). Receipt of ADT was associated with improved survival (adjusted hazard ratio 0.69, 95% confidence interval 0.66-0.73). The benefit of early treatment did not differ from delayed treatment (P = 0.58). A large minority of men with metastatic prostate cancer, particularly black men, receive delayed or no ADT. Early or delayed ADT was associated with similarly prolonged survival. After controlling for patient and tumour characteristics, survival did not differ by race, and receipt of ADT did not contribute to racial differences in survival.