Oral squamous cell carcinoma (OSCC) has locoregional evolution, with frequent neck involvement. Significant number of studies have been undertaken to assess the parameters for treatment of N0 neck patients with a high likelihood of harboring occult node metastases. Many studies have indicated tumor infiltration depth (or tumor thickness) as one of the most important criteria in determining the further management. Growing evidence in the literature shows that tumor infiltration depth is a reliable parameter for predicting regional node involvement and patient survival in OSCC. The substantial agreement among authors, despite the lack of comparable study groups, of measurement techniques, and cutoff values paradoxically enforced its reliability. Further studies are clearly awaited to reach a consensus on these topics to develop therapy protocols that are also based on this parameter. This article is an attempt to substantiate the use of tumor infiltration depth as a prognostic factor for nodal metastasis in OSCC.
Keywords: Lymphatic metastasis; oral cancer; squamous cell carcinoma; tumor infiltration depth; tumor invasion.