PATIENT CHARACTERISTICS: Age: Not specified Performance status: Karnofsky 70%-100% Life expectancy: At least 12 weeks Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 9 g/dL Hepatic: Bilirubin no greater 1.5 times upper limit of normal (ULN) SGPT no greater than 2 times ULN Renal: Calcium no greater than 11 mg/dL Creatinine no greater than 1.5 times ULN Cardiovascular: No significant cardiovascular disease or cardiac arrhythmia requiring medical intervention Other: Hepatitis B surface antigen negative HIV negative No serious concurrent infection No clinically significant autoimmune disease No active gastrointestinal bleeding or uncontrolled peptic ulcer disease No history of inflammatory bowel disease No psychiatric illness that may interfere with compliance in study Not pregnant or nursing