Androgen deprivation with or without radiation therapy for clinically node-positive prostate cancer

Abstract

Background: Clinically lymph node-positive (cN+) prostate cancer (PCa) is an often-fatal disease. Its optimal management remains largely undefined given a lack of prospective, randomized data to inform practice. We sought to describe modern practice patterns in the management of cN+ PCa and assess the effect of adding radiation therapy (RT) to androgen deprivation therapy (ADT) on survival using the National Cancer Data Base.

Methods: Patients with cN+ PCa and without distant metastases diagnosed between 2004 and 2011 were included. Five-year overall survival for patients diagnosed between 2004 and 2006 and treated with ADT alone or ADT+RT were compared. Propensity score (PS) matching was used to balance baseline characteristics, and Cox multivariate regression analysis was used to estimate hazard ratios (HRs) for all-cause mortality.

Results: Of 3540 total patients, 32.2% were treated with ADT alone and 51.4% received ADT+RT. Compared with ADT alone, patients treated with ADT+RT were younger and more likely to have private insurance, lower comorbidity scores, higher Gleason scores, and lower PSA values. After PS matching, 318 patients remained in each group. Compared with ADT alone, ADT+RT was associated with a 50% decreased risk of five-year all-cause mortality (HR = 0.50, 95% CI = 0.37 to 0.67, two-sided P < .001; crude OS rate: 71.5% vs 53.2%).

Conclusions: Using a large national database, we have identified a statistically significant survival benefit for patients with cN+ PCa treated with ADT+RT. These data, if appropriately validated by randomized trials, suggest that a substantial proportion of such patients at high risk for prostate cancer death may be undertreated, warranting a reevaluation of current practice guidelines.