A blood test (FoundationOne® Liquid CDx) with reflex tissue biopsy to detect ESR1 mutations in metastatic breast cancer

You may qualify if

• Diagnosis of metastatic breast cancer that is hormone receptor-positive (ER≥10%), HER2 low or negative (defined as HER2 Imunohistochemistry (IHC) 0, 1+ or IHC 2+/In Situ Hybridization (ISH)-).
• Progression of metastatic breast cancer that is hormone receptor-positive (ER≥10%), HER2 low or negative (defined as HER2 IHC 0, 1+ or IHC 2+/ISH-) while on systemic therapy.
• Currently receiving or have previously received aromatase inhibitor therapy.

You can't join if

• Patients with locally or regionally recurrent breast cancer without evidence of metastatic disease.
• De novo metastatic breast cancer.
• Presence of symptomatic metastatic visceral crisis.
• Participants with inflammatory breast cancer.
• Intact uterus with a history of endometrial intraepithelial neoplasia (atypical endometrial hyperplasia or higher-grade lesion).
• Diagnosis of any other malignancy within 5 years before enrollment, except for adequately treated basal cell or squamous cell skin cancer, superficial bladder cancer, carcinoma in situ of the cervix, or second primary breast cancer.
• Other conditions that, in the opinion of the treating investigator, would preclude the patient from meeting the study requirements or interfere with interpretation of study results.
• Pregnant and breastfeeding women are excluded from the study