부산대학교 도서관

Background: The relationship between 2-[18F]-fluoro-2-deoxy-d-glucose–positron emission tomography (FDG-PET) findings and programmed death ligand-1 (PD-L1) expression has been reported in several cancers. We investigated the correlations of FDG uptake with immune cell counts, including myeloid-derived suppressor cells (MDSCs), and PD-L1 expression in the tumor microenvironment. We examined 72 patients with oral squamous cell carcinoma (OSCC) with immunohistochemistry data for PD-L1, CD8, S100A8, CD15, and CD33. We used the maximum standardized uptake value (SUVmax) to reflect FDG uptake in each patient.Results: High SUVmax and high MDSC counts were associated with poor prognosis. Significantly higher SUVmax was found in patients with high PD-L1 expression and in those with a high CD15+ cell density (P = 0.03 and P = 0.02, respectively). In multiple regression analysis, the tumor size had the greatest effect on SUVmax (P < 0.001), followed by PD-L1 (P = 0.014), and when the tumor size was excluded, CD15 (P = 0.02) was included in the prediction equation. FDG uptake in some cold tumor subgroups, low PD-L1 expression, and a low CD8+ cell density was linked to significantly lower SUVmax than the other variables. High SUVmax was clearly associated with high PD-L1 expression and/or a high CD15+ cell density.Conclusions: FDG uptake was affected by PD-L1 expression and the density of CD15+ cells in cancer tissue. FDG-PET may illuminate the tumor microenvironment immunotypes before biopsy or resection.