Elevations of monocyte and neutrophils, and higher levels of granulocyte colony‐stimulating factor in peripheral blood in lung cancer patients

INTRODUCTION: Immune cells and molecules are considered as clinical biomarkers and potential targets for immunotherapy. Analyses of the composition of peripheral blood cells hold promise for providing a basis for diagnosing and prognosis lung cancer. In this study, we assessed correlations between immune cell subset profiles in peripheral blood and disease prognosis in patients with lung cancer. METHODS: One hundred and thirteen patients with lung cancer and 99 age‐matched healthy people were enrolled in this study. The percentage and cell count of monocytes, neutrophils, T cells, B cells, natural killer (NK), and NKT cells in peripheral blood were analyzed by flow cytometry or peripheral blood analyzer. Serum cytokines and colony‐stimulating factors were detected by enzyme‐linked immunosorbent assay (ELISA). RESULTS: A reduction in antitumor NK cells (p < 0.0001) and an increase in the protumor MDSCs (p < 0.0001) were observed in the lung cancer patients compared with the controls. Monocyte counts were significantly higher in lung cancer patients with histories of smoking (p < 0.05) or drinking (p < 0.01) than in patients with no relevant history or healthy controls. The number of neutrophils and the neutrophil‐to‐lymphocyte ratio (NLR) were particularly higher in patients with liver metastasis (p < 0.01) compared with no metastasis patients or healthy controls. Levels of the monocyte‐derived cytokine interleukin‐6 (p < 0.05), granulocyte colony‐stimulating factor (G‐CSF) (p < 0.0001), and granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) (p < 0.0001) were higher in patients than in controls. G‐CSF levels decreased during the remission phase (p < 0.05), and positively correlated with carbohydrate antigen 19–9 (p < 0.05) and gene mutation (p < 0.05). CONCLUSION: Monocyte and neutrophil counts were higher in peripheral blood in lung cancer patients than in controls, especially when patients had histories of smoking, drinking, and liver metastasis. Serum levels of G‐CSF and GM‐CSF were higher in lung cancer patients, and G‐CSF levels positively correlated with disease severity.