Carcinoma of the tonsillar region: a multivariate analysis of 243 patients treated with radical radiotherapy.

Between October 1964 and June 1990, 243 patients with squamous cell carcinoma of the tonsillar region were treated with continuous-course radical radiotherapy at the University of Florida. All patients had a minimum 2-year follow-up. Patients were staged according to the AJCC system; stage IV was stratified into two subsets: favorable, IVA (T1-T3 or N2A-N3A); and unfavorable, IVB (T4 or N3B). The initial and ultimate local control rates (including surgical salvage) according to T stage were as follows: T1, 87% and 100%, T2, 79% and 92%; T3, 71% and 76%; and T4, 44% and 48%. Multivariate analysis demonstrated that anterior extension of the primary tumor (p = .0001) and T stage (p = .014) were the most significant parameters affecting local control after radiotherapy. For T4 lesions, twice-daily irradiation significantly improved local control (p = .04). The 5-year absolute and cause-specific survival rates as a function of modified AJCC stage were as follows: I, 37% and 100%; II, 55% and 90%; III, 55% and 85%; IVA, 35% and 60%; and IVB, 23% and 38%. The probability of a severe complication was 3% for the entire group of patients.