Purpose: Children with pure fetal histology (PFH) hepatoblastoma treated with complete surgical resection and minimal adjuvant therapy have been shown to have excellent outcomes when compared with other patients with hepatoblastoma. We prospectively studied the safety and efficacy of reducing therapy in all children with stage I PFH enrolled onto two consecutive studies.
Patients and methods: From August 1989 to December 1992, 9 children with stage I PFH were treated on the Intergroup Hepatoblastoma study INT-0098 and were nonrandomly assigned to receive chemotherapy after surgical resection with single-agent bolus doxorubicin for 3 consecutive days. From March 1999 to November 2006, 16 children with stage I PFH enrolled onto Children's Oncology Group Study P9645 were treated with observation after resection. Central confirmation of the histologic diagnosis by a study group pathologist was mandated. The extent of liver disease was assigned retrospectively according to the pretreatment extent of disease (PRETEXT) system and is designated "retro-PRETEXT" to clarify the retrospective group assignment.
Results: Five-year event-free and overall survival for the 9 patients treated on INT-0098 were 100%. All 16 patients enrolled onto the P9645 study were alive and free of disease at the time of last contact, with a median follow-up of 4.9 years. Retro-PRETEXT for the 21 patients with available data revealed seven patients with stage I disease, 10 patients with stage II disease, and four patients with stage III disease.
Conclusion: Children with completely resected PFH hepatoblastoma can achieve long-term survival without additional chemotherapy. When feasible, surgical resection of hepatoblastoma at diagnosis, without chemotherapy, can identify children for whom no additional therapy is necessary.