Capecitabine Compared With Vinorelbine in Treating Women With Metastatic Breast Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed breast cancer * Metastatic disease * Prior treatment with taxanes in the metastatic, adjuvant, or neoadjuvant setting * Taxane-resistant disease allowed regardless of duration of prior therapy NOTE: Resistant disease defined as progression during or within 12 weeks after taxane therapy for metastatic disease or a disease-free interval of less than 12 months after neoadjuvant or adjuvant therapy with a taxane * Taxane-sensitive disease allowed if at least 4 prior courses were received NOTE: Sensitive disease defined as progression occurring more than 12 weeks after taxane therapy for metastatic disease or more than 12 months after neoadjuvant or adjuvant therapy with a taxane * Prior treatment with anthracyclines for metastatic disease or as adjuvant treatment OR medical contraindication to treatment with anthracyclines * At least one unidimensionally measurable lesion (phase II study) * No CNS metastases * Hormone receptor status: * Not specified PATIENT CHARACTERISTICS: Age * 18 and over Sex * Female Menopausal status * Not specified Performance status * Karnofsky 70-100% Life expectancy * Not specified Hematopoietic * Absolute neutrophil count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 Hepatic * Bilirubin no greater than 1.25 times upper limit of normal (ULN) * Transaminases no greater than 2.5 times ULN (5 times ULN if liver metastases present) Renal * Creatinine clearance greater than 50 mL/min Cardiovascular * No symptomatic ventricular arrhythmias * No clinically significant congestive heart failure * No clinical or ECG evidence of myocardial infarction within the past 12 months * No significant coronary artery disease Other * Not pregnant or nursing * Fertile patients must use effective contraception * No prior malignancy within the past 5 years except contralateral breast cancer, nonmelanoma skin cancer, and adequately treated carcinoma in situ of the cervix * No known or prior sensitivity to fluoropyrimidines, including fluorouracil * No pre-existing grade 2 or greater neurotoxicity * No known malabsorption or upper gastrointestinal abnormalities that would affect absorption of study drug * No psychological, familial, sociological, or geographical condition that would preclude study compliance PRIOR CONCURRENT THERAPY: Biologic therapy * No concurrent biologic therapy Chemotherapy * See Disease Characteristics * No more than 2 prior chemotherapy lines for metastatic disease * No prior capecitabine, vinca alkaloids, or continuous fluorouracil * No other concurrent chemotherapy Endocrine therapy * Prior hormonal therapy allowed * No concurrent hormonal therapy Radiotherapy * No concurrent radiotherapy Surgery * Not specified Other * Bisphosphonate therapy for treatment and prevention of bony metastases allowed if initiated prior to study * No other concurrent investigational treatment * No concurrent brivudine with capecitabine