PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: At least 3 months Hematopoietic: Platelet count at least 100,000/mm3 Absolute neutrophil count at least 1500/mm3 Hemoglobin at least 9.0 g/dL Hepatic: Bilirubin no greater than 1.5 mg/dL ALT and AST no greater than 2.5 times the institutional normal values Renal: Creatinine no greater than 1.5 mg/dL Other: Not pregnant or nursing Fertile patients must use effective contraception No uncontrolled systemic infection No other prior or concurrent malignancies except nonmelanoma skin cancer, carcinoma in situ of the cervix, or ductal carcinoma in situ of the breast that have been curatively treated No evidence of delirium, confusion, suicidal ideation, or untreated depression