Hepatoblastoma clinical research: lessons learned and future challenges.

The past four decades has brought significant improvement to the diagnosis, treatment, and outcomes of children diagnosed with hepatoblastoma. These improvements are the results of multidisciplinary and multi-institutional international cooperative trials, such as those conducted by the Children's Oncology Group (COG) or the International Childhood Liver Tumor Strategy Group (SIOPEL) and national studies such as those conducted in Germany and Japan. Due to the different treatment strategies used by the various groups, the information generated has been at times complementary but at other times contradictory. In this manuscript, we will provide a global picture of where "we stand and where we are going" in regards to clinical research of childhood hepatoblastoma. We will focus on lessons learned, especially in reference to the experiences of the COG and SIOPEL study groups, and discuss future challenges.