Introduction
Neuroblastoma is the most common extracranial solid tumor in children.
The advent of multidisciplinary treatment approach (including
chemotherapy, surgery, radiotherapy, and high-dose chemotherapy with
autologous peripheral blood stem cell rescue) has helped improve the
prognosis of patients with neuroblastoma1. However,
patients with refractory or relapsed neuroblastoma have unfavorable
prognosis2,3 despite the development of various
salvage therapies, including irinotecan alone4,
irinotecan with temozolomide5, ICE (ifosfamide,
carboplatin, and etoposide)6, and TOPO-CY (topotecan
and cyclophosphamide)7 regimens. Therefore,
development of new chemotherapy regimens for these patients is a key
imperative.
A study reported the outcomes of IRinotecan, Etoposide, and Carboplatin
(IREC) in five patients with refractory or relapsed neuroblastoma; one
of the patients achieved complete response8. No
further studies have investigated the outcomes of IREC regimen in a
larger cohort. Irinotecan exerts a strong anti-tumor effect by
inhibiting the action of type I topoisomerase9.
Genetic polymorphisms in UGT1A1 are known to be associated with
the development of severe side effects of irinotecan, such as diarrhea
and leucopenia10. In this study, we investigated the
outcomes of IREC therapy in 43 patients with refractory or relapsed
neuroblastoma; in addition, we assessed the impact of UGT1A1 gene
polymorphisms on treatment response and toxicity.