Staging and Treatment Implications in Small Oral Squamous Cell Carcinoma with Bone Infiltration

Background/Objectives: Oral squamous cell carcinoma (OSCC) with bone infiltration is categorized as a T4 tumor regardless of its size. T4 tumors are an indication for postoperative radiotherapy, which could be overtreatment for small oral squamous cell carcinoma (SOSCC) with bone infiltration. Methods: A retrospective study of 189 patients with OSCC with the potential for mandibular infiltration was performed. The influence of the predictive variables on overall survival (OS) and disease-free survival (DFS) was assessed using the Kaplan-Meier method. A random forest approach was applied to determine the importance of each variable for survival in a multivariate context, and a partial correlation analysis was performed. Results: A statistical analysis of the effects of covariates suggested only a small influence of bone infiltration on OS. Patients with bone infiltration had a 5-year OS of 69%, and those without bone invasion had a 5-year OS of 71%. Age, lymph node metastasis, depth of invasion (DOI), and tumor size had the most decisive prognostic influence on survival. Conclusions: Bone infiltration appears to have less prognostic explanatory power than other known variables regarding OS. Therefore, adjuvant therapy should be carefully evaluated.