[Clinical features and prognostic analysis of hepatoblastoma in children under six years old].

Objective: To summarize and analyze the clinical features, treatment effects and related factors affecting the prognosis of hepatoblastoma (HB) in children under six years old. Methods: Clinical data of 382 children with HB under six years old who were pathologically diagnosed at the Pediatric Single Center of Beijing Tongren Hospital from May 2005 to May 2019 were analyzed retrospectively. The factors affecting the treatment effect and survival rate of HB were analyzed. The independent risk factors affecting the prognosis of HB were studied by Cox regression model. The χ(2) test was used to compare the enumeration data between groups. Kaplan-Meier method was used for survival analysis. Log-rank test was used to compare the survival rates among subgroups. Results: Children enrolled were with median age of 1.75 (0.08 ~ 5.92) years old and a male to female ratio of 1.5. Alpha-fetoprotein (AFP) median level was 197 406.5 µg/L at initial diagnosis, and the pathological tissue type was mainly epithelial (55.8%). Preoperative PRETEXT stage was mostly stage III (58.6%). 86 cases (22.5%) had portal vein or hepatic vein, and vena cava invasion. 73 cases (19.1%) had extrahepatic adjacent tissues and organs invasion. Twenty-four cases (6.3%) had tumor rupture and bleeding. 171 cases (44.8%) had distant metastases, and 96 cases (25.1%) had multiple intrahepatic lesions. Patients were followed-up to May 2020 (median follow-up time was 56 months). After comprehensive treatment, 218 cases were completely relieved, and 69 cases were partially relieved, and the treatment efficiency was 75.1%. Kaplan-Meier survival analysis showed that the 1, 3, and 5-years overall survival rates (OS) were 93.7%, 84.0%, and 73.9%, respectively, and the event-free survival rates were 90.5%, 79.2%, and 67.5%, respectively. Comparison of the clinical factors of 5-year OS showed that AFP < 100 µg/L (HR = 3.341, P = 0.005), PRETEXT stage IV (HR = 4.026, P = 0.001), vascular invasion (HR = 2.178, P = 0.019) and distant metastasis (HR = 2.634, P = 0.010) were independent risk factors in each subgroup affecting the prognosis of children with HB, and the difference was statistically significant. Conclusion: HB prognosis is related to AFP level, PRETEXT stage, presence or absence of vascular invasion and distant metastasis. Therefore, its survival and prognosis will be different in the presence of different risk factors.