Clinico-biological Data Collection Study of Metastatic Breast Cancer

Prior treatment

• Prior systemic treatment in metastatic setting
• Patients with exclusive brain metastasis not available for surgery

Other illness

• Other malignancy treated within the last 5 years (except non-melanoma skin cancer or in situ carcinoma of the cervix)

Other

• Coagulopathy or other pathology that contraindicates biopsy procedures
• Pregnant or nursing patient
• Individual deprived of liberty or placed under the authority of a tutor
• Impossibility to submit to the medical follow-up of this clinical trial for geographical, social or psychological reasons

• Written informed consent obtained from the patient prior to performing any protocol-related procedures, including screening biopsy, blood sample, faeces and questionnaires
• Women \> 18 years old at time of written consent
• Patient with histologically confirmed breast cancer
• Breast cancer metastatic disease or locally advanced not eligible for local curative treatment intent with or without personal history of adjuvant therapy for this cancer (chemotherapy, radiotherapy, surgery …)
• Patient with metastases that can be biopsied.
• Performance status ≤ 2 (according to WHO criteria)
• Indication of any systemic therapeutic strategy can be performed alongside this current cohort in accordance with national and / or international recommendations.
• HR and HER2 status on metastatic sites or breast tumor if local recurrence:
  • For group 1 :
  • Histologic and/or cytological confirmation of estrogen-receptor positive (ER+) and/ or progesterone receptor positive (PR+) breast cancer determined by local laboratory testing
  • No HER2-overexpression in the patient's tumor tissue determined by local laboratory testing
  • For group 2 :
  • Histologic and/or cytological confirmation of estrogen-receptor positive or negative and/ or progesterone receptor positive or negative breast cancer determined by local laboratory testing
  • HER2-overexpression in the patient's tumor tissue determined by local laboratory testing
  • For group 3 :
  • Histologic and/or cytological confirmation of estrogen-receptor negative and progesterone receptor negative breast cancer determined by local laboratory testing
  • No HER2-overexpression in the patient's tumor tissue determined by local laboratory testing
• Menopausal status : as per the institutional standard of care
• Patient is willing and able to comply with the protocol for the duration of the study including undergoing treatment and scheduled visits and examinations including follow up.
• Patient must be affiliated to a Social Health Insurance