Correlation of tumor-related immunity with 18F-FDG-PET in pulmonary squamous-cell carcinoma

•The SUVmax of 18F-FDG was significantly correlated with PD-L1.•PD-L1 expression, and SUVmax were independent prognostic factors for OS.•For patients with high SUVmax, PD-L1 was an independent prognostic factor. 2-Deoxy-2-[fluorine-18] fluoro-d-glucose with positron emission tomography (18F-FDG-PET) is a clinically useful tool for cancer evaluation. 18F-FDG accumulation in tumor cells is known to be correlated with the presence of glucose transporter 1 (GLUT1) and hypoxia-inducible factor-1α (HIF-1α). Although anti-programmed death-1 (PD-1) antibody treatments have been approved, no suitable predictor of significant responders has been identified. Based on the existing information, we investigated the relationship between tumor immunity (including PD-L1) and 18F-FDG uptake in patients with surgically resected pulmonary squamous-cell carcinoma (SQC). This study included 167 patients (153 men and 14 women) with SQC who underwent 18F-FDG PET. Tumor sections were stained by immunohistochemistry for GLUT1, HIF-1α, PD-L1, CD4, CD8, and Foxp3. The relationship between clinicopathological features and 18F-FDG uptake was analyzed. Student’s t-test, the χ2 test, non-parametric Spearman’s rank test and the Kaplan–Meier method were used to show associations between variables. The rate of positive PD-L1 expression was 79% (132/167), and PD-L1 expression was significantly associated with GLUT1 (P