Extent of lymph node dissection improves overall survival in pT3N0 non-metastatic renal cell carcinoma patients treated with radical nephrectomy: a propensity score-based analysis.

Background: To assess the impact of lymph node dissection (LND) extent on overall survival (OS) and cancer-specific survival (CSS) in patients with pN0M0 renal cell carcinoma (RCC) treated with radical nephrectomy (RN).

Materials And Methods: Data queried for this study include RCC (2010-2014) from the Surveillance, Epidemiology, and End Results (SEER) program. Kaplan-Meier analyses and multivariate Cox regression models tested the effect of number of removed lymph node (NRN) ≥ 50th percentile on OS and CSS. The associations were evaluated using propensity score (PS) matching adjustment.

Results: A total of 5532 pN0M0 RCC patients were enrolled in our study. The median NRN was 2 (IQR 1-6), the 50th percentile defined patients with NRN ≥ 2. Following PS adjustment, there were no significant differences in clinicopathologic features between two groups of patients except for age. Multivariate model analysis showed that patients with NRN < 2 had worse OS than those with NRN ≥ 2 in pT3 group (HR 1.442; P = 0.032) but not in pT1 and pT2 groups (HR 0.859 and 1.393, P = 0.443 and P = 0.267, respectively). However, patients with NRN < 2 had better CCS than those with NRN ≥ 2 in pT1 group (HR 0.368; P = 0.016) but not in pT2 and pT3 groups (HR 1.674 and 1.325, P = 0.216 and P = 0.176, respectively).

Conclusions: More extensive LND (NRN ≥ 2) at RN is associated with better OS in pT3N0M0 RCC patients while it exerts negative influence on CCS in pT1N0M0 group. Hence, more extensive LND has therapeutic value in pT3 individuals but not in pT1 group.