Interferon Alfa-2b With or Without Radiation Therapy in Treating Patients With Melanoma That Has Metastasized to Lymph Nodes in the Neck, Under the Arm, or in the Groin

RATIONALE: Radiation therapy uses high-energy x-rays to damage tumor cells. Interferon alfa-2b may interfere with the growth of cancer cells. It is not yet known whether giving radiation therapy with interferon alfa-2b is more effective than giving interferon alfa-2b alone in treating melanoma. PURPOSE: Randomized phase III trial to compare the effectiveness of radiation therapy plus interferon alfa-2b with that of interferon alfa-2b alone in treating patients who have melanoma that has metastasized to lymph nodes in the neck, under the arm, or in the groin.