GLUT1 expression in human breast carcinoma: Correlation with known prognostic markers

Background: Breast cancers have been shown to have increased glucose uptake and utilization, and to express the facilitative glucose transporter Glut1. The aim of this study was to determine the biological significance of Glut1 expression in breast cancer. Methods: Paraffin sections of 118 breast cancers were immunostained with antibody to Glut1. The percent of Glut1-positive cancer cells in each tumor was correlated with known prognostic markers, and with patient outcome. Results: Glut1 was expressed in 42% of the tumors. Glut1 immunoreactivity correlated positively with the proliferative activity as determined by Ki-67 immunostaining, and with the total histologic score, and showed negative correlation with bcl-2 immun immunostaining. There was no correlation between the percent of Glut1-immunoreactive cancer cells and estrogen receptor status, tumor size, or lymph node status. Conclusions: 1) Glut1 expression is increased in breast cancers with higher grade and proliferative activity, and 2) glucose transport in the majority of breast cancers may be mediated by a glucose transporters other than Glut1.