Squamous cell carcinoma of the retromolar trigone: Treatment outcomes.

OBJECTIVE: Squamous cell carcinoma (SCC) of the retromolar trigone is uncommon, accounting for 1.4% of all oral cancer cases in Japan. Few studies have examined the optimal treatment for this cancer. The aim of this study was to evaluate the outcome of treatment for primary SCC of the retromolar area.

METHODS: We retrospectively analyzed the outcome and prognosis of 45 patients (38 men, 7 women) with SCC of the retromolar trigone who underwent treatment in our department between July 1992 and March 2011.

RESULTS: Mean age was 62.4 years. Clinical stages were: stage I (n=4, 8.9%); stage II (n=10, 22.2%); stage III (n=5, 11.1%); and stage IVa (n=26, 57.8%). Surgical resection was performed in all patients and 6 patients also received postoperative radiotherapy. Reconstructive surgery using free flaps was performed in 38 patients; postoperative complications occurred in 5 of these patients. The 3-year local control rate was 80%, and the 3-year over all survival rates for stage I, II, III, and IV disease were 100%, 80%, 40%, and 49.2%, respectively. Cause of death was the original disease in 23 cases and other diseases in 2 cases. The most common cause of death from the original disease was cervical lymph node metastasis.

CONCLUSION: The presence of cervical lymph node metastasis was a negative prognostic factor. Marginal mandibulectomy may be selected for patients without distinct bone-marrow infiltration.