Capecitabine, Oxaliplatin and Trastuzumab in Treating Patients With HER2 Positive Metastatic Breast Cancer

Inclusion Criteria:

* Histologic or cytologic diagnosis of breast cancer with evidence of (1) unresectable, locally recurrent, or (2) metastatic disease.·
* HER2 gene amplification by FISH. HER protein overexpression by immunohistochemistry will not be sufficient for entry.·
* At least one measurable lesion as defined by the RECIST.
* Prior hormonal therapy for metastatic disease is allowed.
* Maximum of one prior chemotherapy regimen or trastuzumab-containing regimen for unresectable, locally recurrent or metastatic disease
* Prior radiation therapy is allowed as long as the irradiated area is not the only source of measurable disease.

Exclusion Criteria:

* No prior therapy with capecitabine or oxaliplatin in any setting
* No prior therapy with other platinum compounds·
* No other forms of cancer therapy including radiation, chemotherapy and hormonal therapy within 21 days prior to beginning protocol therapy.·
* No prior unanticipated severe reaction to fluoropyrimidine therapy, or known sensitivity to 5-fluorouracil.·
* No prior fluoropyrimidine therapy for metastatic disease is allowed.
* Prior adjuvant fluoropyrimidine therapy is allowed if completed \> 12 months from study entry.·
* No symptomatic brain metastasis. ·
* No evidence of serious concomitant systemic disorders incompatible with the study ·
* No peripheral neuropathy ·
* No major surgery within 28 days prior to beginning protocol therapy.·
* Negative pregnancy test·
* No current breastfeeding·
* No malabsorption syndrome·
* No evidence of serious concomitant systemic disorders incompatible with the study·
* Patients must not be treated with any of the following while on protocol therapy or within 28 days prior to beginning protocol therapy: sorivudine, brivudine, cimetidine, allopurinol.