Solitary cavitary lung cancer is one of the rare types of lung cancer. Generally, the relationship between cavitary lung adenocarcinoma and immunotherapy remains unknown. We aimed to assess programmed cell death ligand-1(PD-L1) expression and CD8-positive (CD8+) tumor infiltrating lymphocytes (TILs) density, and evaluate their prognostic significance of patients with cavitary lung adenocarcinoma (LUAD).
65 patients diagnosed as solitary cavitary LUAD were included in this study, 30 cases of noncavitary LUAD patients were collected as controls, and their specimens from surgery or biopsy were obtained. Expression of PD-L1 protein and CD8+ TILs were detected by traditional immunohistochemistry and multiplex quantitative immunofluorescence technology. The correlations of PD-L1 expression and clinicopathological features, including overall survival in cavitary LUAD patients was evaluated based on the follow-up data.
Overexpression of PD-L1 protein was detected in the tumor tissues of cavitary LUAD patients compared to the noncavitary LUAD controls. PD-L1 expression level was significantly related to the lymph node (P = 0.001), TNM stage (P = 0.024), and CD8+ TIL status (rs= -0.272, P = 0.025). High PD-L1 expression predicted high mortality rate (P < 0.001), but CD8+ TIL group showed better survival in cavitary LUAD patients (P = 0.011). This phenotype with high PD-L1 expression and low CD8 + TIL predicted poorer overall survival of the patients with cavitary LUAD, compared to the other phenotypes. Moreover, CD8+ TIL was an independent good prognosis factor.
We firstly demonstrated that PD-L1 is upregulated in the cavitary LUAD patients, and high expression of PD-L1 negatively correlated with CD8 T cell infiltrating status. High PD-L1 expression and low CD8 + TIL can predict poorer overall survival of the patients with cavitary LUAD.