Association between lymph node yield and survival among patients undergoing radical nephroureterectomy for urothelial carcinoma of the upper tract

BACKGROUNDPrior studies examining the value of lymph node (LN) dissection (LND) in patients with urothelial carcinoma of the upper urinary tract (UTUC) have produced conflicting results. The objective of the current study was to assess the relationship between LN yield and survival among patients undergoing radical nephroureterectomy (RNU). METHODSThe National Cancer Data Base was used to identify patients with non-metastatic UTUC who were treated with RNU between 2004 and 2012. The association between LN yield and overall survival (OS) was assessed using Cox proportional hazards regression, with adjustment for patient, tumor, and facility characteristics. RESULTSOf the 14,472 patients, 2926 (20%) underwent LND. The median yield was 2 LNs (interquartile range 1-6 LNs). Among the entire cohort and the LN-negative (pN0) subgroup, a higher LN yield was associated with lower all-cause mortality (multivariable hazard ratio [HR] 0.94 per 5 LNs removed, 95% confidence interval [95% CI] 0.89-1.00 [P=.034] for the entire cohort and HR 0.86, 95% CI 0.79-0.94 [P=.001] for the pN0 subgroup). Among patients with positive LNs (pN+), there was no association noted between LN yield and OS; however, positive and negative LN counts were found to be independent predictors of OS (HR 1.27 per 5 positive LNs, 95% CI 1.16-1.39 [P<.001] and HR 0.90 per 5 negative LNs, 95% CI 0.82-1.00 [P=.049]). CONCLUSIONSIn this large, contemporary cohort of patients with UTUC, LND was found to be used infrequently despite evidence that a higher LN yield is associated with lower all-cause mortality. Cancer 2017;123:1741-1750. (c) 2017 American Cancer Society. In the current study, the National Cancer Data Base is used to assess the relationship between the extent of lymph node dissection performed at the time of radical nephroureterectomy for upper tract urothelial carcinoma and overall survival. Among a cohort of 2926 patients, a higher lymph node yield is found to be associated with lower all-cause mortality after adjustment for patient, tumor, and facility characteristics.