AIM: To evaluate the M1 and M2 monocyte phenotype in patients with non-small cell lung cancer(NSCLC) compared to controls. Also, to examine the expression of Th1 and Th2 cytokines in plasma of NSCLC vs controls. METHODS: Freshly prepared peripheral blood mononuclear cells samples were obtained from patients with NSCLC(lung adenocarcinoma and squamous cell lung carcinoma) and from non-cancer controls. Flow cytometry was performed to investigate M1 and M2 phenotypes in peripheral monocytes(classical monocytes CD14+, CD45+ and CD16-) using conventional surface markers. Th1 and Th2 cytokine production was alsoanalysed in the plasma using cytometric bead array technique. RESULTS: There were no significant difference in expression of M1(HLA-DR) and/or M2 markers(CD163 and CD36) markers on classical monocytes in patients with NSCLC compared to non-cancer controls. Expression of CD11 b, CD11 c, CD71 and CD44 was also shown to be similar in patients with NSCLC compared to noncancer controls. Th1 and Th2 cytokines [interleukin(IL)-1β, IL-2, IL-4, IL-5, IL-8, IL-10, IL-12(p70), tumor necrosis factor(TNF)-α, TNF-β, and interferon-γ] analysis revealed no significant difference between patients with NSCLC and non-cancer controls. CONCLUSION: This study shows no alteration in peripheral monocyte phenotype in circulating classical monocytes in patients with NSCLC compared to noncancer controls. No difference in Th1 and Th2 cytokine levels were noted in the plasma of these patients. AIM: To evaluate the M1 and M2 monocyte phenotype in patients with non-small cell lung cancer (NSCLC) compared to controls. Also, to examine the expression of Th1 and Th2 cytokines in plasma of NSCLC vs controls. METHODS: Freshly prepared peripheral blood mononuclear cells samples were obtained from patients with lung cancer and NSCLC (lung adenocarcinoma and squamous cell lung carcinoma) and from non-cancer controls. Flow cytometry was performed to investigate M1 and M2 phenotypes in peripheral monocytes (classical monocytes CD14 +, CD45 + and CD16-) surface markers. Th1 and Th2 cytokine production was also analyzed in plasma using cytometric bead array technique. RESULTS: There were no significant difference in expression of M1 (HLA-DR) and / or M2 markers (CD163 and CD36) markers on classical monocytes in patients with NSCLC compared to non-cancer controls. Expression of CD11 b, CD11 c, CD71 and CD44 was also shown in similar with patients with NSCLC compared to noncancer controls. Th 1 and Th2 cytokines [interleukin (IL) -1β IL-2 IL-4 IL-5 IL-8 IL-10 IL-12 (p70) tumor necrosis factor (TNF) β, and interferon-γ] analysis revealed no significant difference between patients with NSCLC and non-cancer controls. CONCLUSION: This study shows no alteration in peripheral monocyte phenotype in circulating classical monocytes in patients with NSCLC compared to noncancer controls. No difference in Th1 and Th2 cytokine levels were noted in the plasma of these patients.