RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug may kill more tumor cells.

PURPOSE: Phase II trial to study the effectiveness of gemcitabine and cisplatin in treating patients with metastatic breast cancer that has not responded to systemic therapy.

OBJECTIVES: I. Assess the response rate of gemcitabine and cisplatin in the treatment of metastatic breast cancer in patients who have failed one or two systemic regimens. II. Determine time to progression and survival in these patients. III. Define further the toxicity of this two-drug combination in these patients.

OUTLINE: This is a nonrandomized study. Patients receive gemcitabine IV over 30 minutes and cisplatin IV over 1 hour on days 1, 8, and 15 every 28 days. Patients with complete response may receive an additional 2 courses after attainment of complete response status. Treatment continues in the absence of disease progression or unacceptable toxicities for a maximum of 8 courses. Patients are followed every 3 months for 2 years and then at 3 years after treatment.

DISEASE CHARACTERISTICS: Histologic or cytologic confirmation of metastatic breast cancer with two exceptions: -New or enlarging pulmonary nodules demonstrable on two chest radiographs taken at least one month apart OR -Multiple characteristic lytic bone metastasis or liver metastases Measurable indicator lesion Measurable metastatic disease must be bidimensionally measurable except in the case of hepatomegaly that may be unidimensionally measurable Patients receiving bisphosphonates must have a measurable disease other than bone No CNS metastases unless controlled with prior surgery and/or radiotherapy

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: Greater than 3 months Hematopoietic: WBC at least 3500/mm3 or absolute neutrophil count at least 2000/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 0.3 mg/dL above upper limit of normal limit (ULN) AST no greater than 3 times ULN Renal: Creatinine no greater than 0.3 mg/dL above ULN Cardiovascular: No New York Heart Association class III or IV heart disease Other: Physician-estimated oral caloric intake of at least 1200 calories per day No uncontrolled infection or chronic debilitating disease Not pregnant or nursing Women of childbearing potential must use adequate contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: Must have previously received 1 but no more than 2 chemotherapy regimens At least 1 prior regimen administered for metastatic disease At least 1 prior regimen containing an anthracycline or paclitaxel At least 4 weeks since prior chemotherapy Endocrine therapy: Not specified Radiotherapy: At least 3 weeks since prior radiotherapy No prior strontium 89 radiotherapy Prior radiotherapy must have been to less than 25% of bone marrow Surgery: At least 4 weeks since any major surgery