Carboplatin and Gemcitabine in Treating Patients With Locally Advanced or Metastatic Breast Cancer

Inclusion criteria: * DISEASE CHARACTERISTICS: histologically confirmed breast cancer, locally advanced or metastatic disease, recurrent or refractory disease, histological or cytological confirmation required for recurrence in a solitary site * Must have received prior anthracycline and taxane as neoadjuvant, adjuvant, or metastatic therapy * At least 1 measurable site of disease, defined as ≥ 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques or ≥ 10 mm by spiral CT scan * Palpable disease allowed, Lesions that have been irradiated in the advanced setting cannot be included as sites of measurable disease * No nonmeasurable disease only, including the following: * Bone lesions * Leptomeningeal disease * Ascites * Pleural or pericardial effusion * Inflammatory breast disease * Lymphangitic pulmonary disease * Abdominal masses that are not confirmed and followed by imaging techniques * Cystic lesions * No HER2-positive disease, defined as 3+ by IHC OR positive by FISH or chromogenic in situ hybridization * Hormone receptor status not specified * PATIENT CHARACTERISTICS: * Male or female, Menopausal status not specified, ECOG performance status 0-1, Estimated life expectancy ≥ 12 weeks, Not pregnant or nursing, fertile patients must use effective contraception during and for 3 months after completion of study therapy * ANC ≥ 1,500/mm³ * Platelet count ≥ 100,000/mm³ * Hemoglobin ≥ 9 g/dL * ALT or AST \< 2.5 times upper limit of normal (ULN) * Bilirubin normal * Alkaline phosphatase ≤ 2.5 times ULN * Creatinine ≤ 1.25 times ULN OR creatinine clearance \> 40 mL/min * Calcium ≤ 1.2 times ULN * No concurrent serious medical or psychiatric illness, including any serious active infection incompatible with the study * No other primary malignancy except carcinoma in situ of the cervix, adequately treated nonmelanomatous skin cancer, or any other malignancy previously treated ≥ 5 years ago with no evidence of recurrence * No peripheral neuropathy ≥ grade 2 * PRIOR CONCURRENT THERAPY (See Disease Characteristics): * Recovered from prior chemotherapy * Prior hormonal therapy or immunotherapy allowed * Antitumoral hormonal therapy must be discontinued prior to study entry * More than 4 weeks since prior radiotherapy and recovered * No prior radiotherapy to the whole pelvis or to ≥ 25% of the bone marrow * No prior gemcitabine hydrochloride, cisplatin, or carboplatin * No other cytotoxic chemotherapy for 21 days before and for 14 days after completion of study therapy * More than 30 days since prior treatment with a drug (not including study drug) that has not received regulatory approval for any indication at the time of study entry * Bisphosphonate therapy may not be initiated or discontinued within 4 weeks of study entry * No more than 1 prior course of chemotherapy for metastatic disease * Prior chemotherapy in the adjuvant setting allowed * Concurrent palliative radiotherapy to existing painful lesions (soft tissue or bone) allowed * New bone pain requiring radiotherapy \> 4 weeks after first study treatment considered disease progression * New pain in a soft tissue lesion without other objective changes may be irradiated provided ≥ 1 other site of nonirradiated measurable disease exists * No other concurrent anticancer treatment * No concurrent tamoxifen citrate, aromatase inhibitors, or progestagens