Inclusion Criteria:

- adult patients, >=18 years of age;

- HER2 positive breast cancer with locally recurrent or metastatic lesions;

- eligible for chemotherapy;

- baseline LVEF >=50%.

Exclusion Criteria:

- previous chemotherapy for metastatic or locally recurrent breast cancer;

- previous radiotherapy for metastatic breast cancer (except for metastatic bone pain
relief);

- other primary tumor within last 5 years, with the exception of basal or squamous skin
cancer, or in situ cancer of the cervix;

- clinically significant cardiovascular disease;

- chronic daily treatment with aspirin (>325mg/day) or clopidogrel (>75mg/day).