Abstract: Objective To examine the correlation of CCBE1 expression in adjacent tissues of tongue squamous cell carcinoma (TSCC) with pericancerous lymphatic vessel proliferation, cervical lymph node metastasis and survival outcomes of the patients. Methods Lymphatic vessel density was quantified in pericancerous tissue sections of 44 cases of cT1-2N0 TSCC using D2-40 as the lymphatic vessel endothelial marker for calibration and counting of the lymphatic vessels. Of these 44 cases, 22 showed a relatively low lymphatic vessel density (group A) and the other 22 had a high lymphatic vessel density (group B), and the expression levels of CCBE1 in the adjacent tissues determined using immunohistochemistry, immunofluorescence assay and Western blotting were compared between the two groups. The expression level of CCBE1 was also measured in another 90 patients with TSCC using immunohistochemistry, and all the patients were followed up for their survival outcomes. Results Immunohistochemistry and Western blotting showed a significantly lower rate of high CCBE1 expression in group A than in group B (P<0.05). Immunofluorescence assay showed co-localization of CCBE1 and D2-40 in the adjacent tissues of TSCC. In the 90 TSCC patients with complete follow-up data, a high expression of CCBE1 was found to correlate with lymph node metastasis and a poor 5-year survival outcomes of the patients (P<0.05). Conclusion A high expression of CCBE1 in the adjacent tissues of TSCC is closely related with pericancerous lymphatic vessel proliferation, cervical lymph node metastasis and a poor 5-year survival of the patients, suggesting the value of CCBE1 as a potential prognostic predictor for TSCC.

Key words: tongue squamous cell carcinoma; CCBE1; lymphangiogenesis