PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 70-100% Life expectancy: At least 3 months Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: No active liver disease Transaminases no greater than 3 times upper limit of normal (ULN) Renal: Creatinine no greater than 1.5 times ULN OR Creatinine clearance greater than 60 mL/min Cardiovascular: No New York Heart Association class III or IV heart disease Pulmonary: No respiratory disease sufficient enough to influence oxygenation of arterial blood Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception At least 2 weeks since prior infection No concurrent infection No active or clinically relevant viral illness No clinical condition (e.g., effusions or ascites) that would preclude methotrexate administration No known hypersensitivity to antimetabolite chemotherapeutic agents No rheumatic or autoimmune disease No other concurrent malignancies requiring treatment