Malignant Liver Tumors in South African Children: A National Audit

Abstract

Malignant liver tumors (mostly hepatoblastoma [HB] and hepatocellular carcinoma [HCC]) are uncommon, representing 0.5%-2% of childhood malignancies worldwide. The pattern of liver tumors appears to differ in Southern Africa as a result of infectious factors (e.g., hepatitis B/retroviral disease (HIV). This study aimed to assess recent changes in the prevalence and surgical management of liver tumors in South African children. Data were obtained from the tumor registry and pediatric oncology units in South African hospitals to audit and review the epidemiology, treatment, and outcome of malignant hepatic tumors in South African children. Malignant primary hepatic tumors were reported in 274 children (ages 0-14 years) from 1988 through June 2006. Of these 134 (48%) had HB; 77 (27%) had HCC (9 [3%] fibrolamellar subtype); 38 (13%), vascular tumors; and 17 (6%), liver sarcomas. In a further 8 patients (3%) other tumors included lymphoma and endodermal sinus tumor. Vascular tumors included hemangioendotheliomas (12), and there were 5 malignant tumors in children with HIV, including 1 angiosarcoma and 13 Kaposi sarcoma-like tumors. Hepatoblastoma occurred at a mean age of 1.47 years, and none were encountered in patients > 4 years of age. Hepatocellular carcinoma mostly occurred in the older patients (mean age: 10.48 years), but 6% presented in patients < 8 years of age (10 months, 2, 2.6, 5, 5, and 6 years). Hepatic sarcoma occurred at a mean age of 7.66 years and had a female predominance (M:F ratio: 0.4). The relative HCC prevalence (male predominant: hepatitis B related) was reflected in the low HB:HCC (1.67) ratio. However, a significant decrease in HCC was attributed to the effect of hepatitis B inoculation. There appeared to be an increase in the incidence of vascular tumors, presumably the result of an increase in Kaposi-like sarcoma in retrovirus-positive patients. The surgical resection rate was low because most patients presented late, with advanced disease. Survival was 11% and 52% for HB and HCC, respectively, and was related to chemotherapeutic response and complete surgical resection. Liver tumors appear to have a different epidemiological pattern in South Africa. The observed increased HCC prevalence appears to be decreasing with hepatitis B vaccination. Retroviral disease does not yet appear to have a major influence on the distribution of liver tumors in South Africa, although it possibly affects the vascular tumor prevalence.