Effectiveness and mechanism of lymphocytes at different periods in predicting consolidation immunotherapy following adaptive chemoradiotherapy in LA-NSCLC

Objective To explore The role of lymphocytes in prognosis and lymphocyte subsets at different stages of chemoradiotherapy and consolidation immunotherapy in patients with locally advanced non-small cell lung cancer (NSCLC). Methods 139 Patients with Stage IIINSCLC who received adaptive chemoradiotherapy and consolidation immunotherapy were retrospectively enrolled in the final analysis. A paired sample T-test was used to assess the difference among absolute lymphocyte counts (ACLS) and lymphocyte subsets of pre-/post-/during treatmentin different periods. Through the application of univariate and multivariate Cox proportional hazards regression analyses, the determinants influencing the periods of progression-free survival (PFS) and overall survival (OS) were established.The Kaplan-Meier method was used to evaluate the survival prognosis in patients grouped by OS-related independent predictive factors. the PFS and OS. Results There were statistically significant differences among ACLS of before radiotherapy, at the 20th fraction of adaptive radiotherapy, and at one month following radiotherapy, respectively(P < 0.05). According to univariate and multivariate analysis, ACLS at 1 month after radiotherapy, decreased lymphocyte(defined as the difference value of before radiotherapy and the 20th fraction of adaptive radiotherapy), and increased lymphocyte count(defined as the difference value of one month following radiotherapy. and the 20th fraction of adaptive radiotherapy) were identified as Independent predictors of OS ((P < 0.05). KM curve showed that patients with ACLS > 1.015×10 ⁹ at one month following radiotherapy. ACLS with decreased value > 0.71×10 ⁹ , or increase ACLS with increased value > 0.305×10 ⁹ obtained longer OS. There were significant differences in CD4 + and CD8 + counts and CD8/CD4 between before and 1 month after radiotherapy (p < 0.05). KM curve showed the longer OS in patients with the higher level of CD8 + T cell at one month following radiotherapy. (P < 0.05). Conclusion Patients with NSCLC who undergo chemoradiotherapy followed by consolidation immunotherapy exhibit longer OS when they have a higher level of ACLS or CD8 + T cell counts at one month after chemoradiotherapy.