Predictive Significance of Tumor Depth and Budding for Late Lymph Node Metastases in Patients with Clinical N0 Early Oral Tongue Carcinoma

In clinical N0 early oral tongue carcinoma, treatment of occult lymph node metastasis is controversial. The purpose of this study was to assess the histopathological risk factors for predicting late lymph node metastasis in early oral tongue carcinoma. We retrospectively reviewed 48 patients with early oral tongue squamous cell carcinoma. Associations between the histopathological factors (depth of tumor, differentiation, blood vessel invasion, lymphatic invasion, and tumor budding) and late lymph metastasis were analyzed. Although the univariate analysis identified blood vessel invasion, lymphatic invasion, and high-grade tumor budding as predictive factors for neck recurrence (p < 0.001), the Cox proportional hazards model identified high-grade tumor budding as an independent predictive factor (p < 0.01). The combination of a tumor depth >= 3 mm and high-grade tumor budding yielded high diagnostic accuracy. Tumor depth and budding grade were identified as histopathological risk factors for late neck recurrence in clinical N0 early oral tongue carcinoma.