Insulin-like growth factor-1 receptor expression in pediatric tumors: a comparative immunohistochemical study

Background/aim: Insulin-like growth factor-1 receptor (IGF-1R) is a pivotal receptor tyrosine kinase involved in the cell cycle and malignant tumor transformation. It is differentially expressed in various types of tumors. We aimed to determine the expression of IGF- 1R in different pediatric tumors and to shed light on possible new indications of anti-IGF-1R treatment approaches. Materials and methods: A total of 147 specimens were analyzed according to their expression of IGF-1R. Specimens included those from rhabdomyosarcomas, Wilms tumors, Ewing sarcoma/primitive neuroectodermal tumors, peripheral neuroblastic tumors, acute lymphoblastic lymphoma, Hodgkin lymphoma, Burkitt lymphoma, retinoblastoma, pleuropulmonary blastoma, Langerhans cell histiocytosis, endodermal sinus tumors (ESTs), and myeloid sarcoma. Analysis was performed on tissue sections by immunohistochemically staining for IGF-1R expression. Results: All six specimens of EST cases showed positivity for IGF-R1. Additionally, about 56% of the Hodgkin lymphoma, 80% of the rhabdomyosarcoma, and 70% of the Wilms tumor specimens showed positivity for IGF-R1 expression. Conclusion: All ESTs examined in our study expressed IGF-1R and to our knowledge this is the first report regarding ESTs and IGF-1R expression. IGF-1R could be included among confirmatory markers for ESTs and, from a therapeutic viewpoint, ESTs should also be examined for IGF-1R expression for beneficial regimens.