Analysis of prognostic factors in 1180 patients with oral cavity primary cancer treated with definitive or adjuvant radiotherapy

Introduction: The present study identifies the prognostic factors influencing oral cancers in a large cohort of patients treated at a single institute.
Materials and Methods: This is an audit of 1180 patients treated from 1990 to 2004 in the service setting with prospective data collection. Patients were treated with radical radiotherapy or were planned for surgery and post operative radiotherapy (PORT). None of the patients received postoperative concurrent chemoradiation. For analysis, patients were divided into Group 1 and Group 2 based on the oral cavity subsite.
Results: Of the entire cohort, 810 patients had tumors of the Gingivo-alveolo-buccal complex, lip and hard palate (Group 1) and 370 patients had primaries in tongue and floor of mouth (Group 2). Three year locoregional control for the entire cohort was 58%. The three year local control (LC), locoregional control (LRC) and disease free survival (DFS) for PORT group were 74%, 65% and 60%, respectively, with pathological nodal status, perinodal extension and cut margin status showing statistical significance (P <0.001). In the definitive radiotherapy group, the three year LC, LRC and DFS were 34%, 31% and 30%, respectively, with age, T stage, nodal status and stage being significant. Group 1 patients showed significantly better LC, LRC and DFS than Group 2 patients for the entire cohort.
Conclusion: The results indicate superior outcomes with PORT particularly in advanced stages of oral cancer and inferior outcomes in tongue and floor of mouth subsites. There is scope for improving outcomes by adopting treatment intensification strategies.