ABI-007 (Nab-Paclitaxel) and Gemcitabine in Treating Women With Metastatic Breast Cancer

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed invasive breast cancer \- Clinical evidence of metastatic disease \+ No bone metastases or other non-measurable disease as the only evidence of metastasis * Measurable disease, defined as at least 1 measurable lesion \- The following are considered non-measurable disease: * Small lesions (\< 2 cm) * Bone lesions * Leptomeningeal disease * Ascites * Pleural or pericardial effusions * Inflammatory breast disease * Lymphangitis cutis or pulmonis * Abdominal masses that are not confirmed and followed by imaging techniques * Cystic lesions * HER2(human epidermal growth factor receptor 2)-positive disease allowed provided patient has received prior treatment with trastuzumab * No evidence of active brain metastasis, including leptomeningeal involvement * Hormone receptor status: * Not specified PATIENT CHARACTERISTICS: Age * 18 and over Sex * Female Menopausal status * Not specified Performance status * ECOG 0-1 Life expectancy * At least 12 weeks Hematopoietic * Absolute neutrophil count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Hemoglobin ≥ 9 g/dL Hepatic * AST and ALT ≤ 2.5 times upper limit of normal (ULN) * Bilirubin ≤ 1.5 times ULN Renal * Creatinine ≤ 1.5 mg/dL Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception during and for 30 days after completion of study treatment * No pre-existing peripheral neuropathy \> grade 1 * No other clinically significant illness or significant medical condition that would preclude study participation * No history of allergy or hypersensitivity to paclitaxel protein-bound particles in an injectable suspension, paclitaxel, gemcitabine, albumin, drug product excipients, or agents that are chemically similar to study drugs * No serious medical risk factors involving any of the major organ systems that would preclude study participation * No active stage III or IV invasive non-breast malignancy within the past 5 years PRIOR CONCURRENT THERAPY: Biologic therapy * See Disease Characteristics Chemotherapy * No more than 1 prior adjuvant chemotherapy regimen * No prior chemotherapy for metastatic disease * At least 6 months since prior adjuvant or neoadjuvant taxane * More than 2 weeks since prior cytotoxic chemotherapy * Prior neoadjuvant chemotherapy allowed * No other concurrent chemotherapy Endocrine therapy * Prior hormonal treatment as adjuvant therapy or for metastatic disease allowed Radiotherapy * Prior radiotherapy to target lesion allowed provided there is evidence of disease progression after completion of treatment * More than 2 weeks since prior radiotherapy, except radiotherapy to a non-target lesion only or single-dose palliative radiotherapy * No concurrent radiotherapy Surgery * Not specified Other * More than 2 weeks since prior investigational drugs * No concurrent participation in another clinical trial that is studying investigational procedures or therapies * Concurrent bisphosphonates (e.g., pamidronate or zoledronate) allowed for palliation of pain or lytic lesions from breast cancer