Despite treatment improvements in breast cancer, a large number of patients still progress to the metastatic stage. Metastatic breast cancer patients have an extremely unfavorable prognosis. Not only efficacy, but also quality of life are in the focus when planning a therapy or therapy sequence for metastatic breast cancer patients. Therapy options include anti-hormonal Therapy, antibody therapies, other targeted therapies and chemotherapies. One of the most effective chemotherapies in the adjuadjuvant and metastatic setting is paclitaxel. However drug handling and its side effects can compromise patients quality of life and can have an impact on the pharmacokinetics of the drug.

In metastatic breast cancer patients increasing therapy efficacy and reduction of side effect frequency are considered to be advancements of therapy. One of these advancements is the development of a cremophor free and albumin bound paclitaxel, nab-Paclitaxel (Abraxane), which is thought to have a better efficacy and reduced toxicity profile. Nab-Paclitaxel is approved for the treatment of metastatic breast cancer after a failure of first-line therapy and when antracyclines are not indicated.

The SERAPHINA study aims to investigate in the use of nab-Paclitaxel in daily routine and the frequency and perception of side effects.

As a non-interventional study, the SERAPHINA Study will assess the patient characteristics and describe the patient cohort, in which nab-Paclitaxel is given. This includes age distribution and characteristics documented by the patients themselves.

Inclusion Criteria:

• Patients with metastatic breast cancer in which a therapy with nab-paclitaxel was indicated by the treating physician
• Treatment of nab-Paclitaxel must either have not been started yet, or first application of nab-Paclitaxel was not prior to 21 days before study entry
• Female patients, age ≥18 years
• Invasive breast cancer (irrespective of status of BC, e.g. TNM, receptor status etc.)
• Metastatic or locally advanced, inoperable disease proven by clinical measures (i.e. standard imaging)
• Patients scheduled for nab-Paclitaxel treatment in daily routine before screening
• Patients, who are able and willing to sign the informed consent form

Exclusion Criteria:

• Patient is currently enrolled, or will enroll in an interventional clinical study in which investigational therapeutic procedures are performed or investigational therapies are administered while participating in this study

1200 patients with locally advanced/metastatic breast cancer for who is curruently or will be treated with nab-Paclitaxel according to the approval as stated in the Summary of Product Characteristics.