Inclusion Criteria:

- Female patients, age ≥ 18 years

- Advanced or metastatic breast cancer, histologically confirmed

- Documented HER2 overexpression (IHC 3+ and/or FISH positive)

- At least one measurable lesion according to RECIST criteria. Patients with bone-only
lesions are not eligible for study entry

- Documented disease progression

- Patients may have no more than 1 line of palliative treatment, however prior
therapies must include trastuzumab in adjuvant or metastatic setting

- Life expectancy of at least 12 weeks

- Performance status 0-1

- Cardiac ejection fraction >= 50% as measured by echocardiogram or MUGA scan

- Adequate hematology, liver and renal function

Exclusion Criteria:

- Pregnant or lactating women

- Serious medical or psychiatric disorders that would interfere with the patient's
safety or informed consent

- Severe cardiac disease (uncontrolled angina, arrhythmia, chronic heart failure (CHF)
or cardiac disease requiring a device)

- Ejection fraction below the institutional normal limit

- Maximum cumulative dose of 360 mg/m2 for doxorubicin and 720 mg/m2 for epirubicin

- Active bacterial, viral or fungal infection

- Patients with clinically apparent brain metastases

- Positivity for HIV, Hepatitis B or C

- History of other malignancy; patients who have been disease-free for 5 years

- Concurrent cancer therapy (chemotherapy, radiation therapy, immunotherapy, biologic
therapy) or concurrent treatment with an investigational drug or participation in
another clinical trial

- Known hypersensitivity to the study drugs Lapatinib and Caelyx or their excipients