Programmed death-ligand 1 expression and CD8+ tumor-infiltrating lymphocytes in advanced non-small cell lung cancer treated with microwave ablation and chemotherapy.

BACKGROUND: Programmed death-ligand 1 (PD-L1) and CD8+ tumor-infiltrating lymphocytes (TILs) were associated with non-small cell lung cancer (NSCLC). We conducted this study to evaluate the correlation between PD-L1 or CD8+ TILs expression and MWA or survival in advanced NSCLC patients treated with microwave ablation (MWA) plus chemotherapy.

METHODS: Previously untreated, pathologically verified advanced NSCLC patients with adequate tissues for the analysis of PD-L1 expression and the presence of CD8+ TILs were retrospectively enrolled. None of the patients had sensitive mutations, and therefore, they were treated with MWA of the primary tumors followed by chemotherapy.

RESULTS: A total of 51 patients were enrolled. PD-L1 expression and the presence of CD8+ TILs were identified in 31 (60.8%) and 9 (17.6%) patients, respectively. PD-L1 expression and CD8+ TILs had no correlation with baseline characteristics, the response to chemotherapy or MWA. Patients with PD-L1 expression had similar progression-free survival (PFS: 7.9 months for PD-L1-positive vs. 5.8 months for PD-L1-negative; p = .660) and overall survival (OS: 18.7 months for PD-L1-positive vs. 15.2 months for PD-L1-negative; p = .901). Patients with CD8+ TIL expression did not show superior PFS (CD8+ TIL vs. CD8- TIL, 8.0 vs. 6.2 months, p = .435) or OS (CD8+ TIL vs. CD8- TIL, 20.5 vs. 16.9 months, p = .653).

CONCLUSION: PD-L1 expression and the presence of CD8+ TILs could predict neither the patients' response to chemotherapy or MWA nor survival in advanced NSCLC patients treated with MWA plus chemotherapy.