Ipilimumab or High-Dose Interferon Alfa-2b in Treating Patients With High-Risk Stage III-IV Melanoma That Has Been Removed by Surgery

Inclusion Criteria: * All patients must have disease-free status documented by a complete physical examination and imaging studies within 4 weeks prior to randomization; imaging studies must include a total body positron emission tomography (PET)-computed tomography (CT) scan (with or without brain) and brain magnetic resonance imaging (MRI) or CT (if MRI is contraindicated); if PET-CT cannot be done, CT of neck, chest, abdomen, and pelvis should be done * If for some reason a CT cannot be done, an MRI may be done instead; any other imaging studies if performed (eg, bone scan) must show no evidence of disease * Patients must have primary cutaneous melanoma that belong to one of the following American Joint Commission on Cancer (AJCC) stages (2009 AJCC Melanoma Staging System): * Stage IIIB * T1-4b N1a M0 * T1-4b N2a M0 * T1-4b N1b M0 * T1-4b N2b M0 * T1-4b N2c M0 * Stage IIIC * T1-4b N1b M0 * T1-4b N2b M0 * T1-4b N2c M0 * Any T N3 M0 * Stage IV * M1a * M1b * NOTE: patients with stage IV melanoma must have normal lactate dehydrogenase (LDH) and either distant skin, subcutaneous, lymph node, or lung metastases, but no other visceral metastases in order to be eligible; for patients with resected stage IV melanoma, LDH within the institutional upper limit of normal (ULN) must be documented within 4 weeks prior to randomization * Patients with disease recurrence after adequate surgical excision of the original primary c…