Rates and determinants of prostatectomy in prostate cancer (PCa) patients with node-positive disease.

Abstract

362 Background: Consensus guidelines recommend that PCa patients with “regional risk” clinical node positive (cN1) disease undergo EBRT and ADT. However, many of these patients still undergo radical prostatectomy (RP), and the role of clinical node status in predicting benefit from RP is debated. Using National Cancer Database (NCDB), we sought to characterize the rates and determinants of initial RP for cN1 patients, and to assess the prognostic significance of clinical nodal stage for patients undergoing RP with pathologic node involvement (pN1). Methods: Among incident cases of nonmetastatic PCa within NCDB (2004-2012), we identified two cohorts: (1) patients with cN1 disease, and (2) patients with pN1 post-RP. For the cN1 cohort, factors associated with initial RP were evaluated using univariate logistic regression, and post-surgical pathologic staging and adjuvant therapies were described. For the pN1 cohort, multivariate Cox regression was used to compare overall survival (OS) by preoperative clinical stage (cN1 vs cN0). Results: Of 7787 patients with cN1 disease, 2166 underwent initial RP, with consistent annual rates (24-31%) over the study period. Factors independently associated with higher likelihood of RP included age ≤ 65 (HR 1.8), white race (HR 1.4), private insurance (HR 1.8), T stage ≥ T2C (HR 1.3), PSA ≤ 10 (HR 1.6), and Gleason score <8 (HR 1.4). Of cN1 patients who underwent RP, 84% were pN1 and 26% were pN0. 26% of these cN1/pN1 patients later received RT, 49% received ADT, and 20% received both. Separately, among 7396 PCa patients with pN1 disease after RP, 17% were initial cN1 and 83% were cN0. After adjustment for practice setting, patient, and disease variables, initial cN1 clinical stage was associated with significantly worse OS (HR = 1.2, p=0.04). Conclusions: The initial treatment of regional risk cN1 disease is highly variable, with approximately 1 in 4 patients undergoing initial prostatectomy, the vast majority of whom are confirmed pN1. Among all patients with pN1 disease, clinical nodal staging retains prognostic significance for OS. These findings underscore the utility of initial clinical staging when considering initial and adjuvant treatments for regional risk patients.