Correlation of metabolism/hypoxia markers and fluorodeoxyglucose uptake in oral squamous cell carcinomas

Objective. The objective of this study was to analyze the relationship between the uptake of 18F-2-fluoro-2-deoxy-D-glucose (FDG) by positron emission tomography-computerized tomography (PET-CT) and glucose metabolism/hypoxia markers in oral squamous cell carcinoma (OSCC). Study Design. Thirty-six patients with OSCC (tongue [n 23], buc al mucosa [n 7], and floor of the mouth [n 6]) were assessed and underwent incisional biopsy and subsequently received FDG-PET-CT. Expressions of hypoxia-inducible factor 1α (HIF-1α), glucose transporter protein 1 (GLUT-1), hexokinase-II (HK-II), and glucose-6-phosphatase (G6Pase) were immunohistochemically quantified, and FDG uptake was evaluated by the maximum standardized uptake values (SUV _max) at the primary tumor site. Results. FDG uptake was found to be significantly correlated with the T classification of OSCC but not with other clinicopathologic characteristics, such as the N classification, clinical type, and histologic grade of malignancy. In the earlystage (T1 and T2) tumor, FDG uptake was significantly associated with the expression levels of GLUT-1, HK II, and HIF-1, and the expression levels of GLUT-1 and HK-II significantly correlated with HIF-1 expression levels. However, there were no correlations between the expression levels of these molecules and SUV_max in the late-stage (T3 and T4) tumor. Conclusions. FDG uptake was significantly associated with the expression levels of glucose metabolism-related molecules, such as GLUT-1, HK II, and HIF-1α, especially in early-stage tumors.