Characteristics of Disseminated Her2+ Breast Cancer Patients Treated With Trastuzumab That Have Reached Complete, Partial Remission or Stabilization of Disease During More Than 3 Years

SECONDARY OBJECTIVES: * To determine the frequency of patients achieving partial response or stable disease for a period exceeding 3 years. * Know the time to complete or partial remission or to achieve stabilization of the disease. * Know the length of the complete or partial remission or time to disease stabilization of patients. * Knowing the pattern of treatment that has achieved complete or partial remission or stabilization of disease and duration. * Knowledge of overall survival. * Knowing the toxicity of prolonged administration of trastuzumab. * Identify the primary tumor genes HER-2 associated with such prolonged responses. The source document will be in all cases the clinical history and in the case of patients selected for the sub-genetic analysis, the report resulting from it. The study is carried out by filling a notebook of electronic data collection that gathers all available information contained in medical records. The sub-genetic analysis will be performed at the Hospital de la Paz. Both, the processing of samples and conducting the analysis using qRT-PCR, will be performed in this hospital. All data are stored, ensuring the confidentiality, security and authenticity .The forms must be reviewed by the monitor. Once recorded the data, the database will be revised and monitored to submit those records in which there are inconsistencies or missing information . Following the closure of the database will be a report which will present the results of the analysis of the data.