PATIENT CHARACTERISTICS: Age: 18 and over Performance status: GOG 0-2 Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 times normal SGOT/SGPT/GGT no greater than 3 times normal Alkaline phosphatase no greater than 3 times normal No acute hepatitis Renal: Creatinine no greater than 2.0 mg/dL OR Creatinine clearance greater than 50 mL/min Other: No septicemia or severe infection Body surface area at least 1 m2 Adequate intestinal function (i.e., does not require IV hydration or nutritional support) Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception 3 months prior to and during study No other malignancies within the past 5 years except curatively treated skin cancer No other severe medical problems that would prevent compliance No condition of the GI tract that would affect GI absorption and motility No severe gastrointestinal bleeding