Prognostic value of IL-6R mRNA in lung adenocarcinoma and squamous cell carcinoma

Previous studies have demonstrated that the interleukin (IL)-6/ IL-6 receptor (IL-6R) signaling pathway contributes to the pathogenesis of lung cancer. Lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) are the two major pathological subtypes of non-small cell lung cancer (NSCLC). The present study aimed to elucidate the potential clinical prognosis and biological function of IL-6R mRNA expression in LUAD and LUSC. The search term ‘lung cancer’ was used to search through the Gene Expression Omnibus database. Including LUAD and LUSC datasets in The Cancer Genome Atlas database, a total of 8 LUAD and 6 LUSC datasets were included in the present analysis. It was observed that a higher expression level of IL-6R mRNA in tumor tissues was a significant positive prognostic factor for overall survival in LUAD [pooled hazard ratio (HR), 0.48 and P<0.001 for univariate analysis; pooled HR, 0.50 and P<0.001 for multivariate analysis] while there was no similar association in LUSC (pooled HR, 1.59 and P=0.062 for univariate analysis; pooled HR, 1.58 and P=0.079 for multivariate analysis). Correlation analysis revealed that IL-6 and IL-6R were negatively correlated in LUAD and positively correlated in LUSC. IL-6R and its most correlated genes were primarily involved in cell cycle progression in LUAD and primarily involved in tumor angiogenesis, invasion and metastasis in LUSC. These results suggest a possible role of tumoral expression for IL-6R in LUAD, which means it may have potential as a prognostic marker for this type of cancer.