Prognostic Relevance of the Relative Presence of CD4, CD8 and CD20 Expressing Tumor Infiltrating Lymphocytes in Operable Non-small Cell Lung Cancer Patients

Background/Aim: Non-small cell lung cancer (NSCLC) is one of the most lethal tumors. Given the failure of conventional therapeutic strategies, immunotherapy has emerged as a promising treatment modality that may improve the survival of patients with operable and advanced disease. Patients and Methods: We examined the relative presence of CD20+ B-cells, CD8+ cytotoxic, and CD4+ helper/regulatory T-cells in the tumor-infiltrating lymphocyte (TIL)-population in a series of surgically-treated NSCLCs, and assessed their role as prognostic indicators after surgery. Results: A high percent of CD4+ and CD8+ TILs in the tumor stroma was linked with poor (p=0.003) and good prognosis (p=0.01), respectively. High CD4/CD8 ratio defined a significantly worst prognosis [median survival 22 months vs. undefined, p=0.0002, hazard ratio (HR) 0.3 vs. 3.0]. Statistically significant results were also noted when the analysis was focused on the invading tumor front. In a multivariate model, the CD4/CD8-ratio assessed in the tumor stroma and the stage of disease were independent prognostic variables (p=0.0001, HR=4.1 and p=0.001, HR=1.5, respectively). Conclusion: The balance between CD4+ and CD8+ lymphocytes infiltrating the tumor stroma is a crucial factor defining anti-tumor immune surveillance, has strong prognostic value, and may be tested as a predictive biomarker for immunotherapy in operable NSCLC.