Independent Assessment of the Children's Hepatic Tumors International Collaboration Risk Stratification for Hepatoblastoma and the Association of Tumor Histological Characteristics with Prognosis

Abstract

Importance: Hepatoblastoma is the most common pediatric liver malignant neoplasm, and accurate risk stratification is essential for guiding treatment. Objective: To validate the Children's Hepatic Tumors International Collaboration-Hepatoblastoma Stratification (CHIC-HS) in an independent cohort of patients with hepatoblastoma and evaluate the association of pretreatment hepatoblastoma histological subtype with prognosis. Design, Setting, and Participants: This is a single-institution retrospective cohort study of 96 pediatric patients with hepatoblastoma diagnosed and treated between June 1, 2000, and December 31, 2016, with recent therapy and independent of the CHIC-HS discovery cohort. Each patient was assigned a risk group according to CHIC-HS. The histological characteristics of each tumor were assessed based on the International Pediatric Liver Tumor Consensus Classification. Data were analyzed from May 2018 to May 2019. Main Outcomes And Measures: The main outcomes were event-free survival (EFS) and overall survival (OS). Cox regression analysis was used to examine the associations of patient characteristics and tumor histological characteristics with survival. Results: A total of 96 patients (median [range] age, 1.9 [0.4-18] years; 36 [38%] girls and 60 [63%] boys) were assessed, including 15 with very low risk, 28 with low risk, 23 with intermediate risk, and 30 with high risk, according to CHIC-HS criteria. There were a total of 13 cancer-related deaths; median (range) follow-up was 3.5 (0.1-17.8) years for those alive at the last follow-up. The estimated 5-year OS rates were 100% in the very low-risk group, 94.7% (95% CI, 68.1%-99.2%) in the low-risk group, 89.2% (95% CI, 63.1%-97.2%) in the intermediate-risk group, and 57.9% (95% CI, 34.6%-75.5%) in the high-risk group. In a multivariable analysis, we confirmed that CHIC-HS significantly estimated EFS (high-risk group vs very low- and low-risk groups: hazard ratio [HR], 45.59; 95% CI, 9.39-209.5; P