Serum miRNA signature to identify a patient’s resistance to high-dose radiation therapy for unresectable non-small cell lung cancer.

7580 Background: There is a growing literature on unique profiles of serum micro RNAs (miRNAs) expression to predict clinical outcome of metastatic and early stage non-small cell lung cancer (NSCLC). However, the predictive role of circulating miRNAs in unresectable NSCLC treated with definitive radiation therapy (RT) is unknown. Methods: 134 patients with inoperable/unresectable NSCLC treated with definitive RT (18-month minimum follow-up) were eligible. Serum samples were collected prospectively before treatment. 100 patients had enough serum and reliable miRNA profile quality, which were randomly divided into training and validation sets (50 patients each). MiRNA profiling was performed using real-time PCR-based array, containing a panel of 84 miRNAs detectable in human bodily fluids. Spiked-in cel-miR-39 was used for normalization. Stepwise regression Cox model building was used to build a miRNA signature on the training set, which was then assessed on the validation set both alone and with clinical fa...