Totally, 1423 patients from nineteen studies were included to assess the relationships between GLUT1 and clinicopathological parameters, the pooled OR indicated that positive GLUT1 expression was significantly related with classification (adenocarcinomas vs. squamous carcinomas, OR = 0.276, 95% CIs: 0.117-0.651, P = 0.003), tumor differentiation (G3-4 vs. G2~1, OR = 1.944, 95% CIs: 1.384-2.730; P < 0.001), lymph node metastasis (positive vs. negative, OR = 3.65, 95% CIs: 1.82-7.32, P < 0.001),tumor size (large tumor size vs. small tumor size, OR = 2.03, 95% CI: 1.42-2.91, P < 0.001), and advanced tumor stages (OR = 2.527, 95% CIs: 1.325-4.820).
However, no significant correlation was seen between GLUT1 levels and presence of lymph node metastasis, tumor size or the status of human epidermal growth factor receptor 2 (HER2).
While there were no clear statistical relationships between Glut-1 expression and patient sex, resection, tumor location, size, T stage and adjuvant treatment, Glut-1 expression levels were significantly associated with age, tumor-node-metastasis stage, lymph node metastasis and survival.
GLUT-1 expression was also found to be significantly correlated with the presence of lymph node metastasis (n=8, OR=2.14, 95% CI=1.66-2.75, p<0.001), T stage (n=6, OR=1.73, 95% CI=1.17-2.58, p=0.007), higher Dukes stage (n=5, OR=2.92, 95% CI=2.16-3.95, p<0.001), female sex (n=4, OR=2.92, 95% CI=2.16-3.95, p<0.001), and presence of liver metastasis (n=3, OR=1.82, 95% CI=1.06-3.12, p=0.03).
GLUT-1 overexpression was associated with tumor size (>2 cm vs. ≤2 cm; OR=2.16, 95% CI=1.2-3.9, p=0.01) and lymph node metastasis (yes vs. no; OR=3.29, 95% CI=1.38-7.84, p=0.007).
GLUT-1 was highly expressed in the nasopharyngeal tissues of patients with NPC, and its expression was associated with clinical stage, lymph node metastasis, and EB virus infection.
The immunohistochemistry analysis performed on human melanoma samples demonstrated that CSE expression was highest in primary tumors, decreased in the metastatic lesions and was almost silent in non-lymph node metastases.
Comparison of maximum standardized uptake value (SUVmax) of the lesion was made with GLUT1 expression by immunohistochemistry and various clinicopathologic factors including tumor volume, invasion depth, gross finding, and lymph node metastasis.
Recently, it was shown that the increased expression of SLC2A1 in head and neck carcinomas is correlated with lymph node metastasis, poor survival and clinical stage, and revealed that the suppression of SLC2A1 expression by antisense oligodeoxynucleotides decreased glucose uptake and inhibited the proliferation of Hep-2 cells.
The present study shows that GLUT-1 served as a marker indicating that tumors with deep invasion tended to result in a worse prognosis in patients due to either lymph node metastasis, a recurrence of the primary lesion or distant metastasis.
Clinicopathological analyses of carcinoma patients revealed a significant correlation of the VEGF and SLC2A1 expression with the status of lymph-vascular involvement and lymph node metastasis.
It is concluded that (a) Glut1 is expressed as a late event in the carcinogenesis process in human colorectal cancer, and (b) expression of Glut1 in a high proportion of cancer cells is associated with a high incidence of lymph node metastases.