DISEASE CHARACTERISTICS: Histologically proven advanced carcinoma of the breast with documented progression on first line chemotherapy Measurable disease Hormone receptor status: Not specified

PATIENT CHARACTERISTICS: Age: 18 and over Sex: Female Menopausal status: Not specified Performance status: Not specified Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 10 g/dL Hepatic: Bilirubin less than 1.5 times upper limit of normal (ULN) AST no greater than 3 times ULN Alkaline phosphatase less than 2 times ULN unless arising from bone Renal: Creatinine less than 1.5 times ULN Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No other clinically significant disease that would interfere with study evaluations No uncontrolled vomiting that would preclude administration of oral medications HIV negative

PRIOR CONCURRENT THERAPY: Biologic therapy: At least 4 weeks since prior biologic therapy and recovered Chemotherapy: See Disease Characteristics At least 4 weeks since prior chemotherapy and recovered Endocrine therapy: Not specified Radiotherapy: Recovered from prior radiotherapy Surgery: Recovered from prior surgery Other: No other concurrent experimental drugs