OUTLINE: This is a randomized study. Patients are stratified according to prior nodal basin recurrence, site of disease, and extracapsular extension. Following surgery, patients are randomized to receive either interferon alfa-2b alone or five treatments of radiotherapy followed by interferon alfa-2b. Patients receive radiotherapy 2 days a week for 2.5 weeks. Patients receive interferon alfa-2b IV over 20 minutes daily for 5 days for a total of 28 days, followed by subcutaneous injections 3 times a week for 48 weeks. Patients are followed every 3 months for 2 years, then every 6 months for 3 years, then annually thereafter.