Neurovascular Invasion and Histological Grade Serve as the Risk Factors of Cervical Lymph Node Metastases in Early Tongue Squamous Cell Carcinoma

The objectives of this study were to analyze the regional characteristics of the cervical lymph node metastasis and to investigate the factors associated with the risk of lymph node involvement. One hundred seventy-one patients suffering from early primary squamous cell carcinoma (SCC) of the tongue (cT1–2N0) were enrolled. Gender, age, growth site, T stage, histological grade, and neurovascular invasion were statistically analyzed by K-M survival analysis and Cox multivariate analysis to evaluate the relationship between the factors and the neck lymph node metastasis. Of the 171 cases divided into the neck dissection group and observation group, 40 ended up with lymph node metastasis, of which 17 were metastasized to level I, 27 to level II, 10 to level III, 2 to level IV, and 1 to level V. Histological grade and neurovascular invasion were significantly associated with lymph node involvement in univariate and multivariate analyses. Age distribution was found to be significantly associated with the lymph node metastasis in multivariate analysis. The metastasis of early tongue SCC has a certain regularity at different sites. Age was not a critical risk factor for cervical lymph node metastasis after surgery. Tumor size was suspected to exert a negative effect on metastasis by influencing tumor invasion. Histological grade and neurovascular invasion were significantly associated with the risk of cervical lymph node metastasis of early tongue SCC.