Predictive Value of Depth of Invasion of Tongue Squamous Cell Carcinoma for Cervical Lymph Node Metastasis and Prognosis

Objective To investigate the predictive value of depth of invasion (DOI) of tongue squamous cell carcinoma (TSCC) for cervical lymph node metastasis and prognosis.

Methods We retrospectively analyzed the clinical and pathological data of 73 patients with T_1/2 TSCC. ROC curve was used to determine the optimal cut-off value of DOI for predicting cervical lymph node metastasis, and logistic regression analysis was performed to analyze the related factors affecting cervical lymph node metastasis of TSCC. Kaplan-Meier method and Cox regression analysis were used for survival analysis.

Results Among 73 patients, 18 patients were with lymph node metastasis and 55 patients were without lymph node metastasis. The median DOI with and without lymph node metastasis were 8.00 and 5.00 mm, respectively (P=0.003). The optimal cut-off value for DOI was 6.15 mm, with AUC 0.75 (95%CI: 64.1%~87.1%, P=0.001), sensitivity 77.8% and specificity 63.6%. DOI and pathological differentiation were independent prognostic factors for cervical lymph node metastasis in multivariate analysis. DOI, nerve invasion and pathological differentiation were independent prognostic factors of survival in Cox regression analysis.

Conclusion DOI of TSCC patients has important predictive value for both cervical lymph node metastasis and prognosis. Neck lymph node dissection is recommended for patients with DOI > 6.15 mm to improve survival rate and reduce recurrence rate.