 The aim of the CHAT study An open-label, randomized Phase II study of Herceptin trastuzumab, Taxotere docetaxel and Xeloda capecitabine in combination, versus Herceptin trastuzumab plus Taxotere docetaxel, in patients with advanced andor metastatic breast cancers that overexpress HER2 was to test the combination of Trastuzumab and Docetaxel with or without capecitabine as first-line therapy for HER2 positive locally advanced or metastatic breast cancer. 