Immunohistochemical Expression of Glucose Transporter Protein 1 (GLUT1), Ki-67 and Microvessel Density in Soft Tissue Sarcomas

Gucose transporter protein-1 (Glut-1) is one of the proteins up regulated in hypoxic conditions. The presence of hypoxia in tumors is leading to resistance to radiotherapy and chemotherapy and is associated with an increased potential for metastases. Immunohistochemical evaluation of the cell proliferation-associated antigen Ki-67 has recently been used as an excellent indicator of cell proliferation and poor prognosis of soft tissue sarcomas (STS). Assessment of angiogenesis is a potentially useful biological prognostic factor in human solid tumors. The aim of this work is to assess the relation between the expression of Glut 1 and Ki 67 in STS. The study also will correlate their expression and the microvessel density (MVD) with the grading parameters of soft tissue sarcomas.Methods: Immunohistochemical analysis of Glut 1 and Ki 67 was performed using 50 cases of soft tissue sarcomas. Pathologic variables including tumor differentiation, necrosis and mitotic index were assessed. The microvessel density was assessed using image analyzer and it was correlated with the Glut 1 and Ki 67 immunohistochemical overexpression.Results: The frequency of immunopositivity for Glut 1 in our cases of soft tissue sarcomas (STS) was 90%, Glut 1 immunopositivity increased with the histologic grade ( p=0.04), grading parameters and MVD with a statistical significance. The frequency of immunopositivity for Ki 67 in cases of STS was 100%. Ki 67 immunopositivity was significantly associated with the histologic grade, differentiation and mitosis score but no statistical significance was found with the necrosis score. There was a statistically significant association between Glut 1 and Ki 67 immunostaining among the studied STS (P<0.012). There was a highly significant difference in the microvessel densities between different histologic grades of the studied STS (P< 0.001). Grade III STS showed the highest MVD mean (57.5), while GII and GI showed MVD mean 7.5 and 5.7 respectively.Conclusion: Assessment of Glut-1 expression and angiogenesis can be used in conjunction with other well-established factors (clinical stage, histological type, and histological grade) in order to achieve a more reliable prognostic evaluation..