OBJECTIVETo evaluate the coexpression of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor-C (VEGF-C) in human squamous cell carcinoma of the tongue (SCCT) and assess their correlations to neoangiogenesis and lymph node metastasis of the tumor.

METHODSTissue samples of primary SCCT and the metastatic lymph nodes were obtained from 46 patients undergoing surgical resections of SCCT for immunohistochemical detection of COX-2 and VEGF-C expressions.

RESULTSThe over-expression rates of COX-2 and VEGF-C was 82.61% and 73.91% in the primary tumor, respectively, significantly higher than those in normal oral mucosa. A significant correlation was found between the expression scores of COX-2 and VEGF-C with a concordance rate of 82.61% (P<0.01) and a kappa value of 0.495 according to Cohen's kappa test (P<0.01). High expression of VEGF-C, but not COX-2, was correlated to the presence of lymph node metastasis (P<0.05). The mean microvessel density was significant higher in tumors with strong positivity for COX-2 or VEGF-C than in tumors with only weak or negative expressions (P<0.001).

CONCLUSIONThe expressions of COX-2 and VEGF-C are closely correlated in SCCT, and may have clinical value for assessing the prognosis, metastasis and invasion of SCCT, but the mechanism of these proteins in carcinogenesis in SCCT needs further investigation.