Treatment outcomes of patients with primary squamous cell carcinoma of the retromolar trigone.

Objectives/hypothesis: Squamous cell carcinoma of the retromolar trigone (RMT SCC) is a relatively uncommon primary site for oral cavity malignancy. However, given its proximity to the mandible and buccal mucosa, RMT SCC typically exhibits early invasion and generally presents at an advanced stage. Large-sample studies are needed to assess the epidemiology and clinical outcomes of this tumor. Our aim was to describe the determinants of survival in patients with RMT SCC.

Study Design: Retrospective cohort study.

Methods: Retrospective, population-based cohort study of patients in the Surveillance, Epidemiology, and End Results tumor registry who were diagnosed with RMT SCC from 1973 to 2012. Primary endpoints were overall survival (OS) and disease-specific survival (DSS).

Results: A total of 4,022 cases of RMT SCC were identified. The mean age at diagnosis was 65 years. Thirty-nine percent of cases presented with stage IV disease. The median OS by stages I to IV were 73.7, 52.4, 27.5, and 23.4 months, respectively (P < .05). Overall, 34.3% of patients underwent surgery, 23.5% received radiation therapy, and 34.1% had both surgical and radiation therapy. On multivariate analysis, advanced age, greater tumor size, and advanced stage were associated with worse OS and DSS (P < .05), surgery predicted improved OS and DSS (P < .05), and radiation therapy predicted improved OS only (P < .05).

Conclusions: RMT SCC is an aggressive malignancy that portends a poor prognosis, though early-stage tumors (stages I and II) have significantly improved survival. Any surgical intervention independently predicted higher survival outcomes. There may be a role of dual modality approaches, particularly for larger tumors.

Level Of Evidence: 4 Laryngoscope, 128:2740-2744, 2018.