Lymph node involvement predicts poor prognosis in primary tongue adenoid cystic carcinoma: A preliminary study of 54 cases.

PURPOSE: Primary tongue adenoid cystic carcinoma (ACC) is extremely rare. The relationship between the patient's prognosis and the tumor's clinicopathological characteristics is uncertain. The aim of this study was to identify the prognostic factors and analyze the overall outcomes for patients with tongue ACC. PATIENTS AND METHODS: A retrospective analysis of the medical records of patients diagnosed with primary tongue ACC between 1998 and 2008 was conducted. The study comprised 54 patients, with a median age of 53.4 years. The incidence of ACC in the base of the tongue was almost 3.5 times in comparison to that in the mobile portion of the tongue. The 3-year and 5-year overall survival rates were 87.4% and 65.3%, respectively, whereas the 3-year and 5-year disease-free survival rates were 54.3% and 32.8%, respectively. Significant prognostic factors regarding overall survival in univariate analyses included tumor size and lymph node status. RESULTS: A multivariate model identified lymph node status as the only significant independent predictor of overall survival. Further analysis showed that tumor size (P = 0.034), histological grade (P = 0.021), and perineural invasion (PNI, P = 0.023) were three important factors affecting lymph node metastasis. Patients with lymph node metastasis have a higher tendency of developing distant metastasis (P < 0.01). CONCLUSIONS: Lymph node status was a significant determinant of prognosis in primary tongue ACC and could be used for a rational design of treatment strategies in future.