Temozolomide and Interferon Alfa in Treating Patients With Stage III or Stage IV Melanoma

DISEASE CHARACTERISTICS: * Histologically confirmed malignant melanoma * Unresectable stage III or stage IV disease * Ocular, mucosal, or cutaneous melanoma * Measurable disease PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * Karnofsky 70-100% Life expectancy: * Not specified Hematopoietic: * Absolute granulocyte count at least 1,500/mm\^3 * Platelet count at least 150,000/mm\^3 Hepatic: * Bilirubin no greater than 1.5 times upper limit of normal (ULN) * SGOT/SGPT no greater than 3 times ULN * Alkaline phosphatase no greater than 3 times ULN Renal: * Creatinine no greater than 1.5 times ULN OR * Creatinine clearance at least 60 mL/min Cardiovascular: * No history of severe cardiovascular disease * No myocardial infarction within the past 6 months * No unstable angina * No New York Heart Association class III or IV heart disease (congestive heart failure) * No ventricular tachyarrhythmias Other: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * HIV negative * No AIDS-related illness * No frequent vomiting or other medical condition that would preclude oral medication intake (e.g., partial bowel obstruction) * No serious infection requiring IV antibiotics * No psychiatric disorder requiring ongoing therapy or medication * No nonmalignant illness or other medical condition that would preclude study * No other active malignancy within the past 2 years except non-melanoma skin cancer, carcinoma in situ of the cervix, or T1a or b prostate cancer detected initially during transurethral resection of the prostate (TURP) (comprising less than 5% of resected tissue) with PSA level normal since TURP PRIOR CONCURRENT THERAPY: Biologic therapy: * At least 4 weeks since prior biologic therapy or immunotherapy and recovered * No concurrent immunotherapy Chemotherapy: * No prior dacarbazine * No prior temozolomide * No other concurrent chemotherapy Endocrine therapy: * No concurrent systemic corticosteroids Radiotherapy: * At least 3 weeks since prior radiotherapy, interstitial brachytherapy, or radiosurgery * At least 3 weeks since prior radiotherapy to the brain for brain metastases * Prior radiotherapy to indicator lesions allowed if there is evidence of disease progression * Recovered from prior radiotherapy * No concurrent radiotherapy Surgery: * At least 2 weeks since prior surgical procedure requiring general anesthesia and recovered