Treatment outcomes for hepatoblastoma children with pulmonary metastasis and extrapulmonary involvement: experience of 36 cases at a single institution

Background: Hepatoblastoma (HB) was the most common primary liver malignant tumor in children. In this study, we aimed to analyze the clinical characteristics and outcome in HB children with pulmonary metastasis and extrapulmonary involvement. Methods: This retrospective study enrolled 36 HB children with pulmonary metastasis and extrapulmonary involvement from January 2010 to December 2017. Clinical characteristics, treatment and outcomes were collected and analyzed. Survival curves were calculated by Kaplan-Meier method. Results: Thirty-six patients (10 females and 26 males) were recruited, with a mean onset age of 2.13 years (range, 0.33-7.83). Four (11.11%) patients presented with single metastatic pulmonary nodules, 32 (88.89%) patients presented with multiple metastatic nodules in both lungs. There were 10 (27.78%) patients with extrahepatic abdomen involvement, 13 (36.11%) patients with brain metastasis, and 16 (44.44%) patients with vascular metastasis. All patients underwent liver tumorectomy and chemotherapy. The median chemotherapy cycle was 17 (range, 3-39). In addition, 19 (54.29%) patients underwent lung metastasectomy. The patients were followed up to December 2018, with a median follow-up of 32.5 months. At the study closing date, 9 patients were alive, 24 patients had died, and 3 patients were censored. Alpha fetoprotein (AFP) level, PRETEXT stage and distant metastases had significant impact on survival time (all P<0.05). Conclusions: The common sites of extrapulmonary metastasis of HB were blood vessels, brain and extrahepatic abdominal organs. The overall prognosis of HB patients with lung metastasis and extrapulmonary involvement was poor, especially those with PRETEXT stage IV, high AFP level or distant metastases.