Prognostic Significance of Invasion Depth in Oral Tongue Squamous Cell Carcinoma

Abstract

PURPOSE: Staging for tongue carcinoma does not consider its depth of invasion. We aim to determine the prognostic significance of invasion depth in tongue cancer. MATERIALS AND METHODS: Retrospective review of patients with tongue carcinoma who underwent curative surgery between 2002 and 2005; 67 patients were analyzed. Tumors were divided into 2 groups: group A = invasion depth <4 mm; group B = invasion depth ≥4 mm. Recurrence and survival rates were calculated for each group and compared. RESULTS: The local recurrence rate in group B was significantly higher (10 vs. 29.7%, p = 0.048). Group A patients had a superior 5-year overall survival (68.8 vs. 41.6%, p = 0.012), disease-specific survival (67.1 vs. 41.1%, p = 0.026) and local recurrence-free survival (89.5 vs. 65.4%, p = 0.035). Five-year regional recurrence, locoregional recurrence and distant recurrence-free survival rates were not significantly different between the 2 groups (p = 0.390, p = 0.173 and p = 0.207). The impact of invasion depth on survival was maintained on multivariate analysis (p = 0.031). CONCLUSION: Invasion depth is an important prognostic indicator in tongue cancer.