To analyze the expression of lymphocyte subsets in the patients with advanced non-small cell lung cancer (NSCLC) before and after chemotherapy.

A total of 122 patients with advanced NSCLC who received chemotherapy in our hospital from January 2014 to June 2018 were selected as the study subjects (case group) and 64 healthy volunteers were taken as the control group during the same period. The differences of T lymphocyte subsets CD3⁺ (%), CD8⁺ (%), CD4⁺ (%) and CD4⁺ /CD8⁺ cell ratio in each group were compared and analyzed.

The cell ratios of CD3⁺ (%), CD4⁺ (%) and CD4⁺ /CD8⁺ in the case group before and after chemotherapy were significantly lower than those of the control group (P<0.05). The cell ratios of CD3⁺ (%), CD4⁺ (%) and CD4⁺ /CD8⁺ cells in the case group after chemotherapy were significantly higher than those before chemotherapy (P<0.05). The cell ratios of CD8⁺ (%) in the case group before and after chemotherapy were slightly higher than those of the control group, but no significant difference was found (P>0.05). And there was no significant difference in CD8⁺ (%) between the two groups (P>0.05). After chemotherapy, the case group was divided into a disease control group (n=90, 73.77%), which included complete remission (CR) in 0 case, partial remission (PR) in 25 cases (20.49%) and disease stability (SD) in 65 cases (53.28%), and a disease progression group (n=32, 26.23%). There was no significant difference in age and sex between the disease control group and the disease progression group (P>0.05). CD3⁺ (%), CD4⁺ (%), CD8⁺ (%) and CD4⁺ /CD8⁺ in the disease control group had no significant difference compared with the disease progression group before treatment (P>0.05). CD3⁺ (%), CD4⁺ (%) and CD4⁺ /CD8⁺ in the disease control group were significantly higher than those in the disease progression group after treatment (P<0.05). The cell ratios of CD3⁺ (%), CD4⁺ (%) and CD4⁺ /CD8⁺ in both groups after treatment were significantly higher than those before treatment. There was no significant difference in CD8⁺ (%) between the two groups after treatment (P>0.05). After treatment, the areas under curves (AUCs) of CD3⁺ (%), CD4⁺ (%) and CD4⁺ /CD8⁺ in predicting the effect of radiotherapy and chemotherapy in NSCLC patients were 0.789, 0.823 and 0.758, respectively. The cut-off values of the maximum AUCs for CD3⁺ (%), CD4⁺ (%) and CD4⁺ /CD8⁺ were calculated by maximum Yoden index. The cut-off value of CD3⁺ (%) was 65.95% (sensitivity=83.30%, specificity=78.60%, P=0.021), CD4⁺ (%) was 39.81% (sensitivity=87.30%, specificity=85.20%, P=0.034), and CD4⁺ /CD8⁺ was 1.250 (sensitivity=81.20%, specificity=76.70%, P=0.017).

The proportion of T lymphocytes in the patients with advanced NSCL is significantly reduced and the cellular immune function is disordered. The effect of chemotherapy may be related to the expression of T lymphocytes in the peripheral blood of the patients with lung cancer, suggesting that the expression of T lymphocyte subsets in the peripheral blood of the patients with lung cancer may be taken as a marker for predicting the clinical effect of chemotherapy.