For patients receiving Faslodex 500 mg, to compare the effectiveness in terms of Time to Progression (TTP) as a function of the line of treatment (i.e. 1st vs. 2nd vs. 3rd line). For all patients, to collect and explore real-life data on the epidemiology and management of Pseudomyxoma Peritonea (PMP) patients with HR+ advanced breast cancer (ABC) treated with Faslodex 500 mg or exemestane.

Inclusion Criteria:

• Signed written informed consent

• Female postmenopausal patient (or patient post-ovariectomy) and age ≥18 years Postmenopause ist defined as

  • Age ≥ 60 years and natural menopause with menses > 1year ago or
  • FSH and E2 levels in the postmenopausal range or
  • Patients who had bilateral ovariectomy (NCCN V.I. 2009)

• Histologically confirmed ER+ locally advanced or metastatic breast cancer

• Not eligible for curative therapy

• Prior treatment with tamoxifen

• Suitable to undergo endocrine treatment for ER+ ABC with SERD / sAI

• Patient is able to read and understand German

Exclusion Criteria:

• Known hypersensitivity to Faslodex or Exemestane or any compounds of the drugs

• Prior treatment with Faslodex 500 mg or Faslodex 250 mg*

  • for patients who receive treatment with Faslodex 500 mg within this observational study. Patients who are included in the exemestane arm may have received prior Faslodex treatment.

• Prior treatment with Exemestane for patients who receive treatment with Exemestane within this observational study

• Acutely life threatening disease

• Treatment with Faslodex 250 mg/month (previously approved dose)

• Prior palliative chemotherapy

660 patients in 140 sites in Germany. 100 specialists and 40 hospitals. Each site should enrol 4-20 patients