Radiation therapy for squamous cell carcinoma of the tonsillar region: A preferred alternative to surgery?

Purpose: There are no definitive randomized studies that compare radiotherapy (RT) with surgery for tonsillar cancer. The purpose of this study was to evaluate the results of RT alone and RT combined with a planned neck dissection for carcinoma of the tonsillar area and to compare these data with the results of treatment with primary surgery. Patients and Methods: Four hundred patients were treated between October 1964 and December 1997 and observed for at least 2 years. One hundred forty-one patients underwent planned neck dissection, and 18 patients received induction (17 patients) or concomitant (one patient) chemotherapy. Results: Five-year local central rates, by tumor stage, were as follows: T1, 83%; T2, 81%; T3, 74%; and T4, 60%. Multivariate analysis revealed that local control was significantly influenced by tumor stage (P = .0001), fractionation schedule (P = .0038), and external beam dose (P = .0227). Local control after RT for early-stage cancers was higher for tonsillar fossa/posterior pillar cancers than for those arising from the anterior tonsillar pillar. Five-year cause-specific survival rates, by disease stage, were as follows: I, 100%; II, 86%; III, 82%; IVa, 63%; and IVb, 22%. Multivariate analysis revealed that cause-specific survival was significantly influenced by overall stage (P = .0001), planned neck dissection (P = .0074), and histologic differentiation (P = .0307). The incidence of severe late complications after treatment war 5%. Conclusion: RT alone or combined with a planned neck dissection provides cure rates that are as good as those after surgery and is associated with a lower rate of severe complications. J Clin Oncol 18:2219-2225. (C) 2000 by American Society of Clinical Oncology.