CTLA-4 Expression in Tumor-infiltrating Lymphocytes Is Irrelevant to PD-L1 Expression in NSCLC.

Background/aim Treatments containing ipilimumab have shown a good outcome in patients with non-small cell lung cancer (NSCLC) regardless of the PD-L1 tumor proportion score (TPS). However, the association between PD-L1 TPS and the expression of CTLA-4 in tumor-infiltrating lymphocytes is unknown. Patients and methods Fifty-five NSCLC patients who underwent surgery in our hospital were included in this study. We measured the proportions of CTLA-4+ regulatory T cells, and CTLA-4+ CD8 T cells, and statistically analyzed their correlations with the PD-L1 TPS. Results Statistical correlations were found neither between the proportion of CTLA-4+ regulatory T cells to CD8 T cells and the PD-L1 TPS (p=0.2859) nor between the proportion of CTLA-4+ cells in CD8 T cells and the PD-L1 TPS (p=0.1919). Conclusion The proportions of CTLA-4+ regulatory T cells to CD8 T cells and CTLA-4+ cells in CD8 T cells were irrelevant to the PD-L1 TPS in NSCLC patients.