PATIENT CHARACTERISTICS: Age: 18 and over Performance status: CALGB 0-1 Hematopoietic: Granulocyte count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin less than 1.5 mg/dL SGOT less than 2 times normal Renal: Serum creatinine no greater than 1.5 mg/dL Cardiovascular: No cardiac disease Pulmonary: No interstitial pneumonia No fibroid lung Other: Not pregnant or nursing Fertile patients must use effective contraception No psychiatric illness No malabsorption disorder No uncontrolled infection No uncontrolled diabetes mellitus No prior or concurrent malignancy within the past 5 years except carcinoma in situ of the cervix or basal cell skin cancer