Local lymph node involvement in pediatric renal cell carcinoma: A report from the Italian TREP project

BACKGROUND: One of the most important adverse prognostic factors for adult renal cell carcinoma (RCC) is the retroperitoneal lymph node involvement. The aim of this article is to study the prognostic significance of local lymph node involvement in pediatric RCC and the role of retroperitoneal lymph node dissection (RLND) at diagnosis. PROCEDURE: The series included 16 patients with RCC and lymph nodes involvement registered in the Italian Rare Tumors Pediatric Age (TREP) project, accounting for 26.2% of 61 pediatric RCC observed at AIEOP centers. RESULTS: A radical nephrectomy was performed in all cases: at diagnosis in 12 cases, after preoperative chemotherapy (CT) in 4 cases. As a part of the same procedure 9 patients underwent RLND, and 7 received a more limited lymph nodes resection. Five (31.2%) developed disease recurrence 2-34 months after diagnosis (median, 6 months) plus 1 developed progression; 6 patients died, 1 of them from secondary leukemia. Among the nine patients receiving RLND, eight are alive and disease free. This compares with only one patient surviving among the seven receiving a more limited lymph nodes resection. The estimated 25-year PFS and OS rates for all patients were 61.4% (95% CI 33.2-80.5) and 50.8% (95% CI 16.5-77.5), respectively. CONCLUSIONS: Lymph node involvement is an unfavorable prognostic factor in children with RCC. RLND appears to be a critical factor to improve the outcome. However, when compared to similar adult patients, the outcome in children appears to be better, suggesting that pediatric RCC, or the host, may be critical differences.