Determinants of performing radical prostatectomy pelvic lymph node dissection and the number of lymph nodes removed in elderly men

Objective: Controversy persists regarding the adequacy of pelvic lymph node dissection (PLND) and cancer control when comparing minimally invasive radical prostatectomy (MIRP) and open radical prostatectomy (RRP). We characterized determinants of performance and extent of PLND during radical prostatectomy in elderly men. Methods: A population-based study was conducted comprised of 5448 men <65 years undergoing RRP and MIRP during 2004 to 2006 from Surveillance, Epidemiology, and End Results (SEER)Medicare-linked data. Multivariable logistic regression was used to assess the effect of demographic and tumor characteristics, surgical approach, and surgeon volume on the likelihood of performing PLND. Results: PLND was performed for 87.6% vs. 38.3% of men undergoing RRP vs. MIRP (P <.001). Among RRP, 82.6% vs. 4.6% underwent extended vs. limited PLND, with a median yield of 4 vs. 3 lymph nodes (P <.001). Median MIRP PLND yield was 3 lymph nodes. In adjusted analyses, men undergoing RRP vs. MIRP (odds ratio [OR] 16.7; 95% confidence interval [CI], 11.1-25.0), those with few vs. multiple comorbidities (OR 1.4, 95% CI 1.02-1.91), intermediate (OR 1.87; 95% CI 1.48-2.37), and high (OR 2.77; 95% CI 2.02-3.78) vs. low-risk features, and men treated by high-volume surgeons (OR 1.008; 95% CI 1.004-1.011) were more likely to undergo PLND. Conversely, Hispanic (OR 0.68, 95% CI 0.49-0.96) vs. white men were less likely to undergo PLND. Conclusions: Independent of tumor characteristics, men undergoing RRP vs. MIRP were more likely to undergo PLND with greater lymph node yield and racial variation observed. Further studies are needed to determine the appropriate use of PLND.