Risk Factors Associated with Disease Recurrence in Patients with Stage III/IV Squamous Cell Carcinoma of the Oral Cavity Treated with Surgery and Postoperative Radiotherapy.

The purpose of the present study was to identify variables associated with high risk of failure in patients with locally advanced squamous cell carcinoma of the oral cavity (SCC-OC).This retrospective study included 191 patients with stage III-IVb SCC-OC treated with post-operative radiotherapy (RT) or chemoradiotherapy (CRT) between 1995 and 2013. Disease-free (DFS) and overall survival (OS) were analyzed; variables associated with inferior DFS were identified.Seventy-five patients (39%) recurred. DFS and five-year OS were 52% and 54%, respectively. Poorly differentiated tumors (p=0.03), recurrent tumors (p=0.02) and high nodal ratio (p=0.02) were associated with an increased risk of recurrence. CRT was associated with improved DFS in patients with positive margins and/or extracapsular extension (p=0.021).Tumors that are recurrent, high grade, or have high nodal ratio are at risk of recurrence. Presence of these disease features should be taken into consideration for better risk stratification.