This 4 arm study will evaluate the efficacy and safety of 4 neoadjuvant treatment regimens in female patients with locally advanced, inflammatory or early stage HER2 positive breast cancer. Before surgery, patients will be randomized to one of 4 treatment arms, to receive 4 cycles of a)Herceptin + docetaxel b)Herceptin + docetaxel + pertuzumab c)Herceptin + pertuzumab or 4)pertuzumab + docetaxel. Pertuzumab will be administered at a loading dose of 840mg iv, then 420mg iv 3-weekly, Herceptin at a loading dose of 8mg/kg iv then 6mg/kg 3-weekly, and docetaxel at a dose of 75mg/m2 escalating to 100mg/m2 3-weekly. During the entire pre- and post-surgery period all patients will receive adequate chemotherapy as per standard of care, as well as any surgery and/or radiotherapy as required. The anticipated time on study treatment is 3-12 months, and the target sample size is 100-500 individuals.