 This non-interventional prospective study will assess the safety of Herceptin SC subcutaneous administration as used in routine clinical practice. Patients with HER2-positive early breast cancer, naive and non-naive of HER2 treatment who are to be treated in the neoadjuvant and adjuvant setting and scheduled to initiate a treatment with Herceptin SC in routine clinical practice use are eligible to participate. The total study duration is anticipated to be 38 months. 