The prognostic value of tumor-infiltrating lymphocytes in non-small cell lung cancer patients who received neoadjuvant chemotherapy followed by surgery

Background.The relationship between tumor-infiltrating lymphocyte (TIL) levels and the prognosis of patients with non-small cell lung cancer (NSCLC) who receive neoadjuvant chemotherapy followed by surgery is a problem that requires more research. Objectives.To evaluate the prognostic value of TIL levels in patients with NSCLC who received neoadjuvant chemotherapy followed by surgery. Materials and methods.Patients with NSCLC who received neoadjuvant chemotherapy followed by surgery in our hospital from December 2014 to December 2020 were selected for a retrospective analysis.Sections were stained with hematoxylin and eosin (H&E) to evaluate TIL levels in surgically-resected tumor tissues.Patients were divided into TIL-(low-level infiltration) and TIL+ (medium-to high-level infiltration) groups according to the recommended TIL evaluation criteria.Univariate (Kaplan-Meier) and multivariate (Cox) survival analyses were used to analyze the impact of clinicopathological features and TIL levels on prognosis.Results.The study involved 137 patients, including 45 who were TIL-and 92 who were TIL+.The median overall survival (OS) and disease-free survival (DFS) of the TIL+ group were higher than those of the TILgroup.The univariate analysis showed that smoking, clinical and pathological stages, and TIL levels, were the factors influencing OS and DFS.The multivariate analysis showed that smoking (OS, hazard ratio (HR): 1.881, 95% confidence interval (95% CI): 1.135-3.115,p = 0.014; DFS, HR: 1.820, 95% CI: 1.181-2.804,p = 0.007) and clinical stage III (DFS, HR: 2.316, 95% CI: 1.350-3.972,p = 0.002) were adverse factors affecting the prognosis of patients with NSCLC who received neoadjuvant chemotherapy followed by surgery.At the same time, TIL+ status was an independent factor for a good prognosis in OS (HR: 0.547, 95% CI: 0.335-0.894,p = 0.016) and DFS (HR: 0.445, 95% CI: 0.284-0.698,p = 0.001).Conclusions.Medium to high levels of TILs were associated with a good prognosis in NSCLC patients who received neoadjuvant chemotherapy followed by surgery.The levels of TILs are of prognostic value in this population of patients.