Characterization of IGF-1 receptor expression and localization in pediatric tumors of the Central Nervous System upon diagnosis according to WHO 2007 grading

CLEMENT, FLORENCIA; VENARA MARCELA; MAGLIO, SILVANA; MARTÍN, AYELEN; MATHO, CECILIA; PETRE, C; GARCIA LOMBARDI, M; BERGADA, I; PENNISI PATRICIA A

San Diego

Congreso; The Endocrine Society 97th Annual Meeting & Expo; 2015

The Endocrine Society

Background: Central nervous system (CNS) tumors are the most frequent solid tumors in the pediatric population. Histologic grading is a mean of predicting the biological behavior of these tumors and survival is strongly correlated with tumor gradation. The insulin-like growth factor (IGF) system of ligands and receptors are known to play an important role in both normal and neoplastic growth. Recently, nuclear translocation of the type 1 insulin growth factor receptor (IGF-1R) has been demonstrated in tumor tissues. Although the IGF-1R expression has been described in CNS pediatric tumors, information about the intracellular localization and correlation with tumor grade is lacking. Objective: To characterize the expression and intracellular localization of the IGF-1R CNS tumors from pediatric patients according to WHO 2007 grading. Patients and Methods: Thirty four patients (19 males/15 females), median aged 7.9 yrs, (range 0.9-18.3), with CNS tumors without previous medical treatment were included (23 gliomas, 5 medulloblastomas, 6 ependimomas). Formalin-fixed 5µm tumor tissue sections were immunostained for IGF-1Rβ. IGF-1R expression and intracellular localization were scored as positive or negative, nuclear or cytoplasmic respectively. Contingency tables were analyzed using Pearson´s χ2 test to assess relationships between IGF-1R and tumor grade (Low grade I-II; High grade III-IV). Results: IGF-1R staining was positive in 15/20 (75%) low grade tumors and in 14/14 (100%) high grade tumours (χ2 Test:p