Observational Study of Effectiveness and Safety of Trastuzumab Emtansine (T-DM1) in HER2-positive Breast Cancer Patients With Residual Invasive Disease Following Neoadjuvant Chemotherapy and Anti-HER2 Target Therapy

This is an observational, multi-centre study analysing data from patients treated with T-DM1 within the compassionate use program AL41711. During the compassionate use program AL41711, subjects received T-DM1 treatment for a total of 14 cycles or less, in case of disease recurrence or unmanageable toxicity. After the completion of the treatment, and 90 days of wash-out period, they can be enrolled in the study. After the signature of the Informed Consent Form, all their data reported in the medical charts up to then (as detailed in section 12 of the protocol) will be extracted retrospectively and inserted in the study database. From the end of the washout period following the last treatment with T-DM1, each subject will enter in an observation phase for a maximum of 3 years, or until death whichever happens first. This phase will be prospective after the signature of the Informed Consent Form.