Retromolar trigone carcinoma treated by primary radiation therapy: an alternative to the primary surgical approach.

OBJECTIVES To review our experience in the treatment of retromolar trigone carcinoma with radiotherapy as the primary modality and to evaluate the different factors affecting locoregional control and survival. DESIGN We retrospectively examined 46 patients with squamous cell carcinoma of the retromolar trigone treated primarily with radiotherapy from January 1, 1973, to June 31, 2002. Four had T1, 21 had T2, 17 had T3, and 4 had T4 lesions; 25 had N0, 15 had N1, 5 had N2, and 1 had N3 disease. The overall stage was I in 3, II in 18, III in 18, and IV in 7 patients. All patients received conventional once-daily fraction radiotherapy as the primary modality of treatment. Three patients received chemotherapy. Overall survival, cause-specific survival, and locoregional control were estimated using the Kaplan-Meier method. Log-rank statistics were used to identify significant prognostic factors for overall survival and locoregional control. RESULTS The median follow-up was 43 (range, 5-217) months overall and 78 (range, 26-188) months for living patients. The 5-year overall survival and cause-specific survival rates were 47% and 78%, respectively. Favorable prognostic factors for cause-specific survival were a lower tumor stage (univariate and multivariate analysis) and a lower nodal stage (multivariate analysis). The 5-year local control rate was 49% after radiotherapy and 67% after salvage surgery. The 5-year regional control rate was 88%. Favorable prognostic factors were a lower nodal stage and a lower overall stage (univariate analysis). The 5-year locoregional control rate for all patients was 42% after radiotherapy and 70% after salvage surgery. CONCLUSIONS Given the surgical salvage rate in our series and previous published experience, radiation therapy can be used with curative intent for small retromolar trigone carcinomas (T1-T2 lesions). For advanced stages without bone invasion, consideration for concurrent chemotherapy and radiation therapy might increase previous historical locoregional and survival rates.

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