This study was terminated because the National Ethics Committee has not approved the protocol.

The study will be conducted as a multicenter prospective observational cohort study, trying to cover almost all Brazilian States, in a population of ErbB2 positive metastatic breast cancer patients, whose disease has progressed after trastuzumab-containing regimen, comparing outcomes in two groups: Group 1: patients receiving Lapatinib-capecitabine immediately after 1st Trastuzumab progression (second line treatment), and Group 2: patients receiving Lapatinib-capecitabine after 2 or more lines of treatment after 1st trastuzumab progression (third line or greater).

All cases of ErbB2 positive metastatic breast cancer, receiving approved standard treatment with lapatinib-capecitabine, after trastuzumab-containing regimen progression in community setting can participate in this observational study, for a period of 12 months of observation since the start of the lapatinib-capecitabine treatment.

• Women with ErbB2+ MBC (ErbB2 expression confirmed by immunohistochemistry or FISH/CISH, either in the primary tumor or in the metastasis, according to the institution's common practice);
• Older than 18 years old;
• Have received prior treatment with trastuzumab-containing regimen for ErbB2+ breast cancer;
• Progressing after trastuzumab-containing regimen either used for the treatment of metastatic disease or progressing after adjuvant /neoadjuvant trastuzumab treatment;
• Eligible to start standard treatment with Lapatinib-capecitabine at conventional doses, in the community setting;
• Signed consent to participate and release information for this study.

All cases of ErbB2 positive metastatic breast cancer, receiving approved standard treatment with lapatinib-capecitabine, after trastuzumab-containing regimen progression in community setting can participate in this observational study, for a period of 12 months of observation since the start of the lapatinib-capecitabine treatment.

Centers from private and public settings, which have incorporated Lapatinib treatment in their routine clinical practice, will be included in this study. Data on the country, type of center, and facility name will be collected on the case report form for use in the data analysis.