This observational study will evaluate the efficacy, safety and patient reported quality of life of palliative first-line Perjeta (pertuzumab) in combination with Herceptin (trastuzumab) in patients with HER2-positive advanced breast cancer (metastatic or locally recurrent, inoperable) who relapsed after completed adjuvant Herceptin therapy. Additionally, information on selection criteria of breast cancer patients treated first-line with Perjeta, Herceptin and chemotherapy and their treatment duration will be collected and analyzed. Data will be collected from eligible patients for up to 20 months of treatment and 24 months of follow-up.

Inclusion Criteria:

• Female adult patients, >/= 18 years of age
• HER2-positive advanced breast cancer (metastatic or locally recurrent, inoperable) relapsing after completed adjuvant Herceptin therapy
• Indication for first-line treatment with Perjeta in combination with Herceptin and chemotherapy according to the Summary of Product Characteristics
• Prior Herceptin therapy as systemic adjuvant treatment (postoperative treatment in a potentially curable setting); additional upfront neoadjuvant Herceptin therapy is allowed
• No prior chemotherapy and/or immunotherapy for advanced (metastatic or locally recurrent, inoperable) HER2-positive breast cancer

Exclusion Criteria:

• Pregnant or breastfeeding women
• Contraindications to Perjeta, Herceptin or concomitant chemotherapy according to the Summary of Product Characteristics
• No Herceptin treatment for early breast cancer in the adjuvant setting

Female patients with HER2-positive advanced breast cancer (metastatic or locally recurrent, inoperable)who relapsed after adjuvant Herceptin therapy, with indication for treatment with Perjeta in combination with Herceptin