Primary malignant liver tumors in children

Abstract

Liver tumors constitute only 1-4% of all solid tumors in children. Two-thirds of these are malignant. The primary malignant tumors are hepatoblastoma (HB), hepatocellular carcinoma (HCC), rhabdomyosarcoma (RMS), angiosarcoma, rhabdoid tumor, undifferentiated sarcoma and other rarer tumors. Of these HB is the commonest. The diagnosis of HB is based on the radiology, elevated levels of α-fetoprotein (αFP) and the histology/cytology. Staging is essential for risk categorization, risk adapted treatment and prognostication. The commonest staging and risk categorization system used today is PRETEXT system that is being used by nearly all multicentre trials (American, European, German, Japanese) in some way. Treatment of HB is multimodal with surgery and chemotherapy being the main modalities. Survival is not possible without complete surgical resection. Majority of tumors are unresectable at presentation but can be made resectable with chemotherapy, giving a resection rate of more than 85%. Cisplatin is the main stay of chemotherapy and is a part of all multidrug protocols. The 3-y overall survival (OS) today stands at 62%-70% but only 25% patients with metastasis get cured. Panhepatic tumors and those with local factors causing unresectability are now dealt with liver transplantation which has also given a survival rate of nearly 85%. The overall management of HB and HCC has evolved over the past 3 decades giving good long term survival rates for HB, though patients with HCC still do poorly. Successive therapeutic trials have focused attention on increasing the efficiency and reducing the toxicity and long term side effects of the treatment. Among the other uncommon tumors the rhabdoid tumor and angiosarcoma are chemoresistant and have a poor outcome while the undifferentiated sarcoma and rhabdomyosarcoma are now showing better response to the currently used chemotherapy combinations.