This study will evaluate the efficacy of weekly paclitaxel-carboplatin combination plus bevacizumab as first line treatment in patients with metastatic triple negative breast cancer. Furthermore, the efficacy of the combination therapy will be correlated with the presence of circulating tumor cells (CTCs) in this population

Breast cancer with absent or low expression of hormone receptors and HER2 (triple negative) does not respond to hormonal or biological therapy with trastuzumab. However, triple negative breast cancers are highly sensitive to chemotherapy. The combination of paclitaxel and carboplatin administered on a weekly basis is active and well tolerated. Recently, initial therapy of metastatic breast cancer with paclitaxel plus bevacizumab demonstrated prolonged progression-free survival, as compared with paclitaxel alone

Inclusion Criteria:

• Histologically or cytologically confirmed metastatic breast adenocarcinoma
• No HER2 overexpression or gene amplification
• Absent or low ER or PR expression
• No previous therapy for metastatic breast cancer is allowed
• Age 18-75 years
• Measurable disease as defined by the presence of at least one measurable lesion (except bone metastases, ascites or pleural effusions)
• Performance status (WHO) 0-2
• Adequate liver (serum bilirubin <1.5 times the upper normal limit, AST and ALT <2.5 times the upper normal limit in the absence of demonstrable liver metastases, or <5 times the upper normal limit in the presence of liver metastases)
• adequate renal function (serum creatinine <1.5 times the upper normal limit)
• bone marrow (neutrophils ≥ 1.5x 109 /L, and platelets ≥ 100x 109 /L)
• No radiation of measurable disease (except brain metastases)
• No progressive brain metastases according to clinical or radiological criteria
• No brain metastases without prior radiation therapy
• Written informed consent

Exclusion Criteria:

• Active infection
• History of significant cardiac disease (unstable angina, congestive heart failure, myocardial infarction within the previous 6 months, ventricular arrhythmias)
• History of stroke
• Anticoagulation therapy (except of low dose aspirin <325mg)
• Other invasive malignancy except nonmelanoma skin cancer
• Psychiatric illness or social situation that would preclude study compliance
• Pregnant or lactating women