The prognostic value of intraepithelial and stromal innate immune system cells in non-small cell lung carcinoma

Aims: The major value of prognostic markers in potentially curable non-small cell lung carcinoma (NSCLC) should be to guide therapy after surgical resection. The prognostic significance of tumour-infiltrating macrophages, their growth factor, macrophage colony-stimulating factor (M-CSF), and its receptor, colony-stimulating factor-1 receptor (CSF-1R), as well as natural killer cells and dendritic cells, is controversial. The aim of this study was to elucidate the prognostic significance of these markers in the epithelial and stromal compartments of NSCLC. Methods and results: Tissue microarrays from 335 resected NSCLC, stage I-IIIA were constructed from duplicate cores of epithelial and stromal areas. Immunohistochemistry was used to evaluate epithelial and stromal areas for CD68, M-CSF, CSF-1R, CD56 and CD1a. On univariate analysis, increasing numbers of stromal CD1a+ (P = 0.011) and CD56+ cells (P = 0.014) correlated significantly with improved disease-specific survival (DSS). On multivariate analysis, stromal CD56+ cells were an independent prognostic factor for DSS (hazard ratio = 2.3, confidence interval = 1.1, 5.0, P = 0.031). Conclusions: High density of stromal CD56+ cells is an independent factor associated with improved prognosis in resected NSCLC, suggesting that these cells mediate an antitumour immune response in the tumour stroma.