Relationships of cervical lymph node metastasis to histopathological malignancy grade, tumor angiogenesis, and lymphatic invasion in tongue cancer.

Cervical lymph node (CLN) metastasis from oral cancer correlates with poor prognosis. Therefore, accurate assessment of CLN status is crucial in treatment planning. However, there are few reports focusing on CLN metastasis from tongue cancer. Further, the growth and progress of the tumor are known to be profoundly related to histological malignancy, tumor angiogenesis, and lymphangiogenesis. Thus, this study aimed to identify predictive factors for CLN metastasis in tongue squamous cell carcinoma (SCC). Initial biopsy specimens obtained from 30 patients with tongue SCC were examined to evaluate histological malignancy according to Anneroth's classification. In addition, blood vessel density, lymph vessel density, and lymphatic invasion in the tumor were evaluated immunohistochemically using CD31, CD34, D2-40, and AE1/AE3, and then the relationships of CLN metastasis to these parameters were investigated. Histological malignancy grade, blood vessel density, and lymphatic invasion were significantly related to CLN metastasis (P < 0.05), but there was no relationship between lymph vessel density and CLN metastasis. However, double immunostaining showed that lymphatic invasion by tumor cells was significantly related to CLN metastasis. The results indicate that Anneroth's histological malignancy grade of 16 or more, tumor blood vessel density of more than 37, and the presence of lymphatic invasion by tumor cells can be predictive factors for CLN metastases in tongue SCC.