Improved survival with lymph node sampling in Wilms tumor.

Objective: We sought to determine the impact of number of lymph nodes examined on survival for Wilms tumor (WT).

Methods: Data from the Surveillance, Epidemiology, and End Results and Florida Cancer Data System were queried for patients < 20 years of age with WT.

Results: Of 1805 WT patients, 1340 had lymph node (LN) data available following surgery. The mean age for the cohort was 3.3 ± 2.8 y. Most patients were White (78%), and non-Hispanic (78%). A total of 297 patients (22%) had 0 LN sampled, while 697 (52%) had 1-5 LN, 210 (16%) had 6-10 LN, and 136 (10%) had >10 LN. Overall 5-y survival was 91%. By univariate analysis, 5-y survival was significantly lower for patients with 0 LN sampled (87% versus 91% 1-5 LN; 93% 6-10 LN; 95% >10 LN, P = 0.005). Multivariate analysis confirmed a survival advantage for patients having 1-5 LN (HR 0.600, P = 0.016), 6-10 LN (HR 0.521, P = 0.048), and >10 LN (HR 0.403, P = 0.039) compared with patients with 0 LN examined.

Conclusion: Failure to biopsy lymph nodes for WT patients not only increases the risk of local recurrence due to understaging and inadequate adjuvant therapy, but is also an independent prognostic indicator of lower survival.