Patient description: The patient is a 42 year-old postmenopausal woman who had a screening sonogram which revealed an abnormality in the right breast. She had no palpable masses on breast exam. Core biopsy was done and revealed a 1.8 cm infiltrating ductal breast carcinoma in the left upper outer quadrant. Lumpectomy was done and the surgical margins were clear. The tumor was HER2-positive and ER/PR negative. Axillary sampling revealed 1 positive lymph node out of 12 sampled. CXR was unremarkable. She is using “well women” multivitamins daily and no other medication. She smokes frequently and consumes alcohol occasionally. She is in a relation with only one partner and has a history of 3 pregnancies and live births. She breastfed all three children.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Carcinoma Breast Stage IV Female gender 2. Age >= 18 years 3. ECOG performance status < 2 4. Histologically proven diagnosis of breast cancer 5. Locally advanced and/or metastatic disease 6. Life expectancy of three months or longer 7. No concurrent second malignancy (except for adequately treated basal cell carcinoma of the skin, in situ carcinoma of the cervix or contralateral breast cancer). Any prior second malignancy must be in remission for >= 5 years (except for contralateral breast cancer). 8. No other serious illness or medical condition including History of documented congestive heart failure; angina pectoris requiring antianginal medication; evidence of recent (< 6 months) transmural infarction on electrocardiogram (ECG); poorly controlled hypertension (e.g. systolic > 180 mmHg or diastolic greater than 100 mmHg); clinically significant valvular heart disease; or high-risk uncontrolled arrhythmias Chronic lung disease History of significant neurological or psychiatric disorders that would prohibit the understanding and giving of informed consent, including psychotic disorders, mental retardation, and dementia Active concurrent infection 9. No symptomatic central nervous system (CNS) metastases 10. No rapidly progressive visceral metastases requiring immediate chemotherapy 11. No concurrent anti-cancer treatment is allowed. 12. Prior investigational biological agents are allowed, with the exception of anti-HER-2 therapy for any reason. 13. Previous hormonal therapy is allowed, as adjuvant and/or for metastatic breast cancer (MBC). 14. Adjuvant and MBC chemotherapy allowed, provided that a minimum of 4 weeks interval has elapsed between last chemotherapy administration and first study drug dose. All patients who, in the opinion of the investigator, could benefit from single agent Herceptin® and are not considered suitable for treatment with chemotherapy plus Herceptin® can be considered for this protocol. 15. A maximum cumulative dose of previous doxorubicin < 360 mg/m2 or a maximum cumulative dose of epirubicin < 720 mg/m2 16. Concomitant use of bisphosphonates is allowed, however if bisphosphonates are started during the trial for worsening bone pain, patients should be assessed for possible progressive disease. 17. Adequate organ function as defined by Neutrophils >= 1.5 x 10^9/L Platelets >= 100 x 10^9/L Bilirubin <= 1.5 x upper limit of normal (ULN) Transaminases <= 2.5 x ULN or <= 5 x ULN if liver metastasis Creatinine <= 1.5 x ULN 18. Overexpression of HER-2 in the invasive component of the primary tumor, according to one of the following definitions