Correlation between glucose transporter type-1 expression and 18F-FDG uptake on PET in oral cancer

ABSTRACT

OBJECTIVES: Fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) is a non-invasive diagnostic tool for many human cancers wherein glucose uptake transporter-1 (GLUT-1) acts as a main transporter in the uptake of 18F-FDG in cancer cells. Increased expression of glucose transporter-1 has been reported in many human cancers. In this study, we investigated the correlation between 18F-FDG accumulation and expression of GLUT-1 in oral cancer. MATERIALS AND METHODS: We evaluated 42 patients diagnosed with oral squamous cell carcinoma (OSCC) and malignant salivary gland tumor as confirmed by histology. 42 patients underwent pre-operative 18F-FDG PET, with the maximum standardized uptake value (SUVmax) measured in each case. Immunohistochemical staining was done for each histological specimen, and results were evaluated post-operatively according to the percentage (%) of positive area, intensity, and staining score. RESULTS: For OSCC, SUVmax significantly increased as T stage of tumor classification increased. For malignant salivary gland tumor, SUVmax significantly increased as T stage of tumor classification increased. For OSCC, GLUT-1 was expressed in all 36 cases. GLUT-1 staining score (GSS) increased as T stage of tumor classification increased, with the difference statistically significant. For malignant salivary gland tumor, GLUT-1 expression was observed in all 6 cases; average GSS was significantly higher in patients with cervical lymph node metastasis than that in patients without cervical lymph node metastasis. Average GSS was higher in OSCC (11.11+/-1.75) than in malignant salivary gland tumor (5.33+/-3.50). No statistically significant correlation between GSS and SUVmax was observed in OSCC or in malignant salivary gland tumor. CONCLUSION: We found no statistically significant correlation between GSS and SUVmax in OSCC or in malignant salivary gland tumor. Studies on the various uses of GLUT during 18F-FDG uptake and SUV and GLUT as tumor prognosis factor need to be conducted through further investigation with large samples.