Role of Androgen Deprivation Therapy for Node-Positive Prostate Cancer

Abstract

To determine the impact of adjuvant androgen deprivation therapy (ADT) for patients who have node-positive prostate cancer in the prostate-specific antigen (PSA) era. We used linked Surveillance, Epidemiology and End Results-Medicare data to construct a cohort of men who underwent radical prostatectomy (RP) between 1991 and 1999 and who had positive regional lymph nodes. We classified men as receiving adjuvant ADT if they received ADT within 120 days of RP, and we compared them to the men who had not received adjuvant ADT. We used propensity scores to balance potential confounders of receiving adjuvant ADT (ie, tumor characteristics, extent of nodal disease, demographics, receipt of radiation therapy) and Cox proportional hazard methods to measure the impact of adjuvant ADT on overall survival (OS), stratified by propensity score quintile. We conducted a sensitivity analysis that used 90, 150, 180, and 365 days as the definition for adjuvant ADT. A total of 731 men were identified, 209 of whom received ADT within 120 days of RP. There was no statistically significant difference in OS between the adjuvant ADT and non-ADT group (HR, 0.97; 95% CI, 0.71 to 1.27). There was no statistically significant survival difference with 90, 150, 180, and 365 days as the adjuvant ADT definition. Deferring immediate ADT in men with positive lymph nodes after RP may not significantly compromise survival. Because observational studies should be considered hypothesis-generating studies, these results should be validated in a prospective fashion in a similar patient population.