A quantitative evaluation of the histological type dependence of the programmed death-ligand 1 expression in non-small cell lung cancer including various adenocarcinoma subtypes: a cross-sectional study

The association between non-small cell lung cancer histology and programmed death-ligand 1 expression remains controversial. We retrospectively analyzed histological dependence of the programmed death-ligand 1 expression by a multiple regression analysis of 356 non-small cell lung cancer patients. The programmed death-ligand 1 expression patterns of adenocarcinoma were consistent with a pathological predominant growth pattern as a reference to papillary adenocarcinoma: minimally invasive adenocarcinoma[partial regression coefficient (B), 0.17; 95% confidence interval, 0.05-0.59], lepidic adenocarcinoma (B, 0.46; 95% confidence interval, 0.23-0.90), acinar adenocarcinoma (B, 1.98; 95% confidence interval, 1.05-3.76) and solid adenocarcinoma (B, 5.11; 95% confidence interval, 2.20-11.9). In histology other than adenocarcinoma, the programmed death-ligand 1 expression tended to be high with poor differentiation: adenosquamous carcinoma (B, 4.17; 95% confidence interval, 1.05-16.6), squamous cell carcinoma (B, 4.32; 95% confidence interval, 2.45-7.62) and pleomorphic carcinoma (B, 13.0; 95% confidence interval, 4.43-38.2). We showed quantitatively that the programmed death-ligand 1 expression in non-small cell lung cancer tended to be clearly histology-dependent, with more poorly differentiated histology showing a higher expression.