Distribution of CD4+ and CD8+ T cells in tumor islets and stroma from patients with non-small cell lung cancer in association with COPD and smoking

Background and objectiveThe immune system plays an important role in non-small cell lung cancer (NSCLC) and chronic obstructive pulmonary disease (COPD). The aim of this study was to evaluate the infiltration patterns of CD4+ and CD8+ T cells in NSCLC and to analyze their relation to COPD, smoking status and other clinicopathologic variables.Materials and methodsLung tissue specimens from 50 patients who underwent surgery for NSCLC (stages I–III) and 10 control group subjects were analyzed immunohistochemically.ResultsNSCLC patients had a greater number of CD4+ and CD8+ T cells infiltrating the lung tissue than the control group (P = 0.001) with predominant infiltration in the tumor stroma. We found a significant association between the number of total and tumor stroma-infiltrating CD4+ and CD8+ T cells, and smoking status (P < 0.05).There were more CD8+ T cells in the tumor stroma and fewer in the tumor islets in NSCLC patients with COPD as compared to NSCLC patients without COPD (P < 0.05). However, there was no such association between CD4+ T cells and COPD status. A high level of CD8+ T cell infiltration in the tumor stroma was independently associated with the coexistence of COPD in multivariate analysis (P < 0.05).ConclusionsAccording to our data, COPD but not smoking seems to be associated with higher infiltration of CD8+ T cells in the tumor stroma of patients with NSCLC. It allows us to hypothesize that NSCLC patients with coexisting COPD may have a more favorable outcome due to anticancer properties of stromal CD8+ T cells.