A nomogram model based on peripheral blood lymphocyte subsets to assess the prognosis of non-small cell lung cancer patients treated with immune checkpoint inhibitors

BACKGROUND: The primary aim of this study was to investigate the prognostic value of peripheral blood lymphocyte subsets in non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors (ICIs). METHODS: From 2018 to 2019, 82 patients diagnosed with stage IIIB–IV NSCLC at Zhejiang Cancer Hospital were recruited for this study. Peripheral blood lymphocyte subsets of NSCLC patients were analyzed using flow cytometry before and after ICI treatment. The relationship between the percentage of peripheral blood lymphocyte subsets, clinicopathological features, progression-free survival (PFS), and overall survival (OS) was identified by correlation heat map, Kaplan-Meier curve, log-rank test, and Cox regression analysis. RESULTS: The CD4/CD8 ratio and the percentage of B cells was decreased after ICI treatment. Furthermore, the percentage of CD3(+) T cells, natural killer (NK) cells, and natural killer T (NKT) cells before ICI treatment was associated with brain metastases, the proportion of CD3(+)CD4(+) T cells before ICI treatment was related to epidermal growth factor receptor (EGFR) status, the CD4/CD8 ratio before ICI treatment was correlated to pathology, the ratio of B cells before ICI treatment was related to therapeutic regimen, and the percentage of NKT cells before ICI treatment was associated with use of radiotherapy. Furthermore, univariate survival analysis revealed that low percentage of B cells forecasted a poor OS for NSCLC patients with ICI treatment. In addition, the nomogram developed by percentages of peripheral blood lymphocyte subsets could determine survival probability and survival time of NSCLC patients with immunotherapy. CONCLUSIONS: ICI treatment induced changes in the percentage of peripheral blood lymphocyte subsets, which had prognostic value for brain metastases, radiotherapy, EGFR status, pathology, and therapeutic regimen, along with prognostic value, for NSCLC patients treated with ICIs.