Glut-1 expression and enhanced glucose metabolism are associated with tumour grade in bone and soft tissue sarcomas: a prospective evaluation by [F-18]fluorodeoxyglucose positron emission tomography

Purpose: This study was conducted to investigate whether F-18-fluorodeoxyglucose (FDG) uptake, quantified by positron emission tomography ( PET), correlates with histological variables including tumour grade, cell proliferation, cell cycle control integrity and glucose metabolism in patients with bone and soft tissue sarcomas. Methods: Eighty-two patients clinically suspected of having a bone or soft tissue sarcoma underwent FDG PET within 1 week prior to operation and 63 patients ( mean age 48 years, range 18 - 74 years) were enrolled in the complete analysis. We excluded 17 patients with pathologically confirmed benign tumours and two patients with uncontrolled diabetes or concomitant malignancy from data analysis. Maximum and average standardised uptake values (SUVs) of the primary lesion were compared with histological variables including tumour differentiation, the presence of necrosis, MIB-1 score, mitotic score, p53 overexpression, MIB-1 grade, mitotic grade and GLUT-1 expression. Results: Significant correlations were found between maximal and mean SUVs and MIB-1 grade, mitotic grade, MIB-1 score, tumour differentiation and mitotic score. The mean and maximal SUVs were significantly higher in tumours with p53 overexpression than in those without p53 overexpression ( p< 0.0001). GLUT-1-positive tumours had significantly higher mean (6.5 +/- 4.2 vs 1.1 +/- 0.2, p= 0.006) and maximal SUVs (8.8 +/- 5.4 vs 1.7 +/- 0.5, p= 0.005) than the GLUT-1-negative tumours. GLUT-1 intensity correlated positively with both mean (r= 0.500, p< 0.0001) and maximal SUVs ( r= 0.509, p< 0.0001). Multiple linear regression analysis showed a significant correlation between maximal SUV and MIB-1 grade ( p< 0.0001). Conclusion: The enhanced glucose metabolism, as determined by SUV, is a strong index of tumour grade in bone and soft tissue sarcomas.