Glut1 Expression and FDG Uptake in Non-small Cell Lung Carcinoma: Its Relationship to Histopathologic Types and Proliferation Rate

ABSTRACT

PURPOSE: 18F-fluoro-2-deoxy-d-glucose (18F-FDG) positron emission tomography (PET) is known to be useful in the detection of lung cancer. However, the degree of FDG uptake was variable. To correlate FDG activity on PET with various histopathologic factors,we assessed the relationships between 18F-FDG uptake and glucose transporter 1 (Glut1) expression, histologic subtypesand Ki-67 labelling indices. MATERIALS AND METHODS: One hundred two patients with non-small cell lung cancer (NSCLC) who had surgery and preoperative 18F-FDG PET scan as a part of the staging work-up were enrolled in this study. The amount of FDG uptake in the primary lesion was measured by a standardized uptake values (SUVs) and correlated with tumor size, histologic subtypes, and immunohistochemical results of Glut1 and Ki-67 labelling indices. RESULTS: Cell type of NSCLC were 52 adenocarcinomas, 36 squamous cell carcinomas, 14 other NSCLC. All tumors could be detected by FDG PET. Uptake was correlated with tumor size (p<0.01). The FDG uptake was significantly lower in adenocarcinomas than in squamous cell carcinomas or other NSCLC (p<0.001). The percentages of Glut1- positive area and staining intensity of the tumor were also significantly lower in adenocarcinomas than in squamous cell carcinomas or other NSCLC (p<0.001). Ki-67 labelling indices of the tumor correlated with the percentage of Glut1 intensity and SUVs in NSCLC (p7lt;0.001). CONCLUSION: These results suggest that overexpression of Glut1 and proliferating activity is related to 18F-FDG uptake in NSCLC. Glut1 expression appear to be different among histologic subtypes. Glut1 expression, as well as FDG uptake, is lower in adenocarcinomas than squamous cell carcinomas or other NSCLC.