Login to Access Video or Poster Abstract: MP53-17
Sources of Funding: None

Introduction

The optimal treatment approach for lymph node positive prostate cancer (PC) disease (pN1) at the time of radical prostatectomy (RP) and pelvic lymph node dissection (PLND) is uncertain. The aim of our study is to examine current treatment of pN1 and evaluate patient and disease-specific predictors of overall survival (OS).

Methods

The National Cancer Database (NCDB) was used to identify pN1 patients between 2004-2013. We examined subsequent treatment; radiation (RT) and/or antiandrogen therapy (ADT). Logistic regression was used to identify clinical and oncologic characteristics associated with different treatments. Finally, survival analyses were performed to examine the effect of these treatments on overall survival (OS), adjusted for covariates.

Results

A total of 336,798 PC patients had undergone RP & PLND. pN1 was recorded in 11,742 (3.5%). Approximately half underwent observation (51%), RT alone was used in 7%, RT&ADT were used in 17% and ADT alone was used in 25%. Adjusted multivariate logistic regression indicated that RT+/-ADT was used for younger and healthier patients who had underwent limited PLND (≤5 nodes examined), with adverse pathological feature (i.e. intermediate or high grade Gleason score, with locally advanced disease (pT3 or T4) and positive margins. Median follow-up for the entire cohort was 48 months. Unadjusted Kaplan Meier analysis demonstrated significant differences in OS favoring RT+/-ADT over observation and ADT alone (p<0.0001). Five-year OS was 85.7% for observation, 88% for RT& ADT, 89.5% for RT alone and 83% for ADT alone (p<0.0001). Adjusted Cox proportional hazards regression demonstrated an improved OS for RT+ADT compared with other groups (Hazard ration 0.75, 95%CI( 0.64 to 0.89), P=0.001). OS was worse in older men, with worse comorbidity score, higher Gleason score and stage, positive margins and > 2 positive LNs.

Conclusions

Our study suggests that pN1 disease may be currently undertreated. The combination of RT&ADT appears to offer a survival advantage in select patients. These results highlight the importance of a multimodal approach in the treatment of node-positive prostate cancer._x000D_

Funding

None