Hilar lymph node involvement in pediatric liver cancer and its impact on outcomes: A systematic review

Management of liver tumors in children is well-defined, with clear treatment protocols established by organizations such as the International Society of Pediatric Oncology-Liver group (SIOPEL), the Children's Oncology Group (COG), and the Japanese Study Group for Pediatric Liver Tumors (JPLT). However, no structured approach exists for hilar lymph node (LN) resection. Surgical practices vary among centers, reflecting the adult setting. This systematic review aims to examine the current evidence on hilar lymphadenectomy in pediatric patients with primary liver tumors and to assess LN positivity rates and their associations with recurrence and survival.

A structured literature search was conducted on MEDLINE, Embase, and Web of Science (2004-January 2025) using keywords: lymph node, hepatoblastoma, hepatocellular carcinoma, and liver tumor. Patients under 21 years were included. The study protocol was registered on PROSPERO (CRD42024501895), and Rayyan software supported screening and review.

Eight studies (880 patients) were included. Diagnoses were hepatoblastoma (HB, n = 277), hepatocellular carcinoma (HCC, n = 507), and other tumors (n = 96). LN dissection details were available for 431 patients: 349 (80.9%) had no metastases. In the HB group, 43% underwent hilar LN dissection with 0% positivity. In HCC, 33.6% had positive nodes. In other tumors, 7.8% showed LN involvement. Data on survival impact were limited.

In HB, routine LN dissection may be unnecessary due to universally negative nodes. For HCC, the one-in-three positivity rate supports further evaluation of lymphadenectomy. Evidence remains limited for other tumors. Prospective multicenter studies using standardized protocols are needed to define the role of LN evaluation beyond HB.