CD4/CD8 co-expression shows independent prognostic impact in resected non-small cell lung cancer patients treated with adjuvant radiotherapy

BackgroundThough traditionally regarded as immunosuppressive, radiotherapy may also stimulate immune cells and facilitate an anti-tumor immune response. We therefore aimed to explore the prognostic significance of immune cell markers in non-small cell lung cancer (NSCLC) patients treated with postoperative radiotherapy (PORT).MethodsIn addition to demographic and clinicopathological information, tumor tissue samples were collected and tissue microarrays (TMAs) were constructed from 55 patients with stage I-IIIA NSCLC who received PORT. Tumor and stromal expression of CD1a+, CD3+, CD4+, CD8+, CD20+, CD56+, CD68+, CD117+ and CD138+ cells, as well as M-CSF and CSF-1R, was assessed by immunohistochemistry.ResultsIn univariate analysis, high co-expression of CD4+ and CD8+ T lymphocytes as well as high expression of CD1a+ dendritic cells in the tumor stroma correlated with improved disease-specific survival (DSS). In multivariate analysis patients with stromal ↓CD4/↓CD8 expression had a hazard ratio of 21.1 (CI95% 3.9–115.6, P < 0.001) when compared to those with ↑CD4/↑CD8 expression.ConclusionsStromal ↓CD4/↓CD8 expression was an independent negative prognostic factor for survival in NSCLC patients receiving PORT, indicating a highly detrimental prognosis.