Overexpression of GLUT1 in colorectal cancer is independently associated with poor prognosis.

Background: To investigate the expression of glucose transporter 1 (GLUT1) in colorectal cancer (CRC) and its relationship to clinicopathological variables.

Methods: The expression of GLUT1 in 163 primary tumors together with the corresponding normal mucosa, and 36 liver metastases was examined using real-time PCR.

Results: The mean value of GLUT1 was higher in primary tumors (50.390 ± 68.648) than in the corresponding normal mucosa (20.437 ± 28.703, p<0.0001), while there was no significant difference in GLUT1 expression between CRC and liver metastasis (50.390 ± 68.648 vs 52.277 ± 52.482, p=0.190). In CRCs, GLUT1 expression was higher in poorly differentiated than in well and moderately differentiated tumors (p=0.022), and higher in stage III + IV than in stage I + II tumors (p=0.035). The patients with high-expressed GLUT1 had a worse prognosis than those with low-expressed GLUT1 independently of gender, age, tumor site, stage and differentiation (p=0.026, RR 2.737, 95% CI 1.126-6.651) in stage I-III CRCs. In liver metastasis, GLUT1 expression was higher in larger tumors than in smaller ones (p=0.025).

Conclusions: Overexpression of GLUT1 in stage I-III CRCs was independently associated with poor prognosis.