Insulin-like growth factor receptor 1 mRNA expression as a prognostic marker in advanced non-small cell lung cancer.

The insulin-like growth factor 1 receptor (IGF1R) has yet to be established as a biomarker in non-small cell lung cancer (NSCLC) but could prove useful in customized chemotherapy. We explored its prognostic value using both quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC). Analyses of IGF1R were performed on patients with advanced NSCLC, included in a randomized chemotherapy trial, having large, representative tissue samples. IGF1R mRNA and protein expression were correlated to clinical end-points. Surgical tissue samples were available from 33 patients deemed inoperable. IGF1R status varied according to histopathology. Patients with tumors positive for IGF1R mRNA expression had a shorter progression-free and overall survival when compared to the negative sub-group (6.1 vs. 7.4 months, p=0.039 and 10.9 vs. 14.3 months, p=0.038, respectively). IGF1R protein expression showed a similar, although non-significant tendency. IGF1R mRNA expression may be a prognostic biomarker in advanced NSCLC and should be investigated in a larger population.