Upfront window vincristine/irinotecan treatment of high-risk hepatoblastoma: A report from the Children's Oncology Group AHEP0731 study committee

BACKGROUND: The identification of new therapies for high-risk (HR) hepatoblastoma is challenging. Children's Oncology Group study AHEP0731 included a HR stratum to explore the efficacy of novel agents. Herein, the authors report the response rate to the combination of vincristine (V) and irinotecan (I) and the outcome of patients with high-risk hepatoblastoma. METHODS: Patients with newly diagnosed metastatic hepatoblastoma or those with a serum α-fetoprotein (AFP) level <100 ng/mL were eligible. Patients received 2 cycles of V at a dose of 1.5 mg/m²/day intravenously on days 1 and 8 and I at a dose of 50 mg/m²/day intravenously on days 1 to 5. Patients were defined as responders if they had either a 30% decrease in tumor burden according to Response Evaluation Criteria In Solid Tumors (RECIST) or a 90% (>1 log₁₀) decline in their AFP level. Responders were to receive 2 additional cycles of VI intermixed with 6 cycles of the combination of cisplatin, doxorubicin, 5-fluorouracil, and vincristine (C5VD). Nonresponders were to receive 6 cycles of C5VD alone. RESULTS: A total of 32 patients with a median age at diagnosis of 26 months (range, 11-159 months) were enrolled between September 2009 and February 2012. Fourteen of 30 evaluable patients were responders (RECIST and AFP in 6 patients, RECIST only in 3 patients, and AFP only in 5 patients). The median AFP decline after 2 cycles of VI for the entire group was 345,565 ng/mL (85% of the initial AFP). The 3-year event-free and overall survival rates were 49% (95% confidence interval, 30%-65%) and 62% (95% confidence interval, 42%-77%), respectively. CONCLUSIONS: The VI combination appears to have substantial activity against HR hepatoblastoma. The ultimate impact of this regimen in improving the outcomes of children with HR hepatoblastoma remains to be determined. Cancer 2017;123:2360–2367.