Expression of IGF1R Is Associated with Tumor Differentiation and Survival in Patients with Lung Adenocarcinoma

Purpose The insulin-like growth factor 1 receptor (IGF1R) is widely expressed in normal tissues and many malignancies in humans. We investigated the clinical significance of the expression of the IGF1R gene in human lung adenocarcinoma. Methods A total of 238 patients with lung adenocarcinoma were investigated. Quantitative real-time reverse-transcription polymerase chain reaction (RT-PCR) assays were performed to evaluate the gene expression of IGF1R , and immunohistochemical staining was done to evaluate the protein expression of IGF1R. Results Among the 238 patients with lung adenocarcinoma, 107 tumors (45.0%) were IGF1R -low and 131 tumors (55.0%) were IGF1R -high. The IGF1R gene expression ratio was significantly lower in moderately to poorly differentiated adenocarcinomas than in well-differentiated adenocarcinomas ( P = 0.0388). Gene expression of IGF1R was significantly correlated with protein expression of IGF1R ( r = 0.7163, P