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