Is radiation therapy a preferred alternative to surgery for squamous cell carcinoma of the base of tongue?

Purpose: To evaluate irradiation alone for treatment of base-of-tongue canc er. Patients and Methods: Two hundred seventeen patients with squamous cell car cinoma of the base of tongue were treated with radiation alone and had foll ow-up for greater than or equal to 2 years. Results: Local control rates at 5 years were as follows: T1, 96%; T2, 91%; T3, 81%; and T4, 38%. Multivariate analysis revealed that T stage (P = .000 1) and overall treatment time (P = .0006) significantly influenced local co ntrol. The 5-year rates of local-regional control were as follows: I, 100%; II, 100%; III, 83%; IVA, 64%; and IVB, 65%. Multivariate analysis revealed that the following parameters significantly affect the probability of this end point: T stage (P = .0001), overall treatment time (P = .0001), overal l stage (P = .0131), and addition of a neck dissection (P = .0021). The rat es of absolute and cause-specific survival at 5 years were as follows: I, 5 0% and 100%; II, 81% and 100%; III, 65% and 76%; IVA, 42% and 56%; and IVB, 44% and 52%. Severe radiation complications developed in eight patients (4 %). Conclusion: The likelihood of cure after external-beam irradiation wets rel ated to stage, overall treatment time, and addition of a planned neck disse ction. The local-regional control rates and survival rates alter radiation therapy were comparable to those after surgery, and the morbidity associate d with irradiation was less. (C) 2000 by American Society of Clinical Oncol ogy.