Gene-expression Profiling in Non-small Cell Lung Cancer with Invasion of Mediastinal Lymph Nodes for Prognosis Evaluation

Background/Aim: The aim of the study was to determine the pathways and expression profile of the genes that might predict response to neoadjuvant chemotherapy in patients with stage IIIA non-small cell lung cancer (NSCLC). Materials and Methods: We evaluated, by microarray, the gene-expression profile of tumoral mediastinal lymph node samples surgically removed from 27 patients with stage IIIA NSCLC before neoadjuvant chemotherapy treatment. Depending on the response to the induction treatment, the patients were divided in two groups: group A: patients whose disease evolved, stabilized or who had minor response to chemotherapy, and group B: patients whose disease stabilized or had major response to chemotherapy. Results: The microarray experiments identified 1,127 genes with a modified expression in the tumoral tissue compared to normal tissue with p <= 0.05 and 44 genes with p <= 0.01. The identified up-regulated genes between tumoral versus normal tissue included collagen, type I, alpha 1 (COL1A1), inhibin beta A (INHBA) and thioredoxin interacting protein (TXNIP). Pathways identified with a false-discovery rate of <0.005 included: cytokine pathways, focal adhesion or extracellular matrix receptor interaction. Conclusion: Our approach identified important characteristics of NSCLC and pointed-out molecular differences between sub-groups of patients based on their response to therapy.