Insulin‐like growth factor‐1 receptor is associated with better prognosis in classical Hodgkin's lymphoma: Correlation with MET expression

The purpose of this study was to examine the prognostic significance of insulin‐like growth factor‐1 receptor (IGF‐1R) expression alone and in relation to the expression of the MET‐ receptor and the MET‐homologous receptor RON, in classical Hodgkin's lymphoma (cHL). Tumour samples from patients with cHL (n = 202; median age 37.5 years) were analysed retrospectively for IGF‐R1, MET or RON expression by immunohistochemistry using tissue microarrays. The median follow‐up time was 3.7 years (range, 0.1–20 years). Twenty‐nine patients (14.3%) expressed IGF‐1R protein in Hodgkin/Reed–Sternberg (HRS) cells, which was associated with a better overall survival (OS) (P = 0.036). IGF‐1R expression was closely associated with MET receptor expression and low level of lactate dehydrogenase. In patients with cHL receiving doxorubicin, bleomycin, vinblastine and dacarbazine, those expressing IGF‐1R showed a trend towards better OS and event‐free survival than IGF‐1R‐negative patients (P = 0.129 and P = 0.115 respectively), but statistical significance was not reached. This study suggests that IGF‐1R expression could be associated with better clinical outcome in cHL but is significantly associated with the expression of MET receptor.