Objectives
In Thailand, the cancer mortality rate had been increasing in numbers over the years. (1) Among them, oral cavity cancer is the seventh most common cancer in Thai male, and the tongue is the most common site. The incidence of oral tongue cancer is 2.2 and 1.0 per 100,000 males and females, respectively. Overall, the 5-year survival rate of oral cavity cancer is 25.9%, where tongue cancer has the worst prognosis. (3)
In general, the tumor, lymph node, distant metastasis (TNM) staging system has been used to predict the disease prognosis, where size, number, and location of the tumor (T) and lymph node (N) and the presence of distant metastasis (M) are the primary considerations. However, in recent studies, the tumor volume has increasing evidence for its possible prognostic implication. Particularly in head and neck cancer, the tumor volume is a promising prognostic factor for predicting disease recurrence and distance metastasis. (4-5)
Therefore, our study aims to explore the use of relevant nodal volume on its prognostic implication and the possible application of nodal volume in addition to the current staging system.