Efficacy of irinotecan single drug treatment in children with refractory or recurrent hepatoblastoma--a phase II trial of the childhood liver tumour strategy group (SIOPEL).

PURPOSE: To assess the clinical activity of irinotecan as single drug in children with refractory or recurrent hepatoblastoma. PATIENTS AND METHODS: Four cycles of irinotecan were administered (20mg/m(2)/day intravenous (i.v.) infusion on days 1-5 and 8-12, every 21days) unless tumour progression occurred or resectability was achieved earlier. Tumour response was assessed according to modified SIOPEL and Response Evaluation Criteria In Solid Tumours (RECIST) criteria. Main end-points were best overall response rate (RR), early progression rate (EPR) and progression free survival (PFS).
RESULTS: Twenty-four eligible patients (median age 58.0months; 19 boys) were enrolled in the study (11 relapses, 13 refractory diseases). Of the 23 evaluable patients six had an overall partial response, 11 stable disease and six progressive disease, of which four were early progression (RR: 26%, EPR: 17%). In eight patients the residual tumour could be completely resected; seven patients became tumour free. At last follow-up 12 patients were alive (six with no evidence of disease, six with disease). PFS at 1year was 24%. Patients with relapse had a higher RR than patients with refractory disease (46% versus 8%) and patients with isolated lung lesions showed a better response than patients with other tumour localisations (50% versus 13%). The main grade 3-4 toxicities, diarrhoea and neutropenia, occurred in half of the patients.
CONCLUSION: Irinotecan has a significant anti-tumour activity and acceptable toxicity in patients with relapsed hepatoblastoma and therefore should be considered for the treatment of these patients. Exploration of the role of irinotecan in the initial treatment of hepatoblastoma is warranted.