The estrogen-dependent nature of breast cancer was first reported in 1896 with the publication of George Beatson's observations on the regression of breast cancer following oophorectomy. Endocrine therapy, targeting ER either directly by selective estrogen receptor modulators (SERMs) and pure antagonists or indirectly by aromatase inhibitors (AIs) that block estrogen production, remains the mainstay of treatment of hormone-sensitive breast cancer in the adjuvant and metastatic settings.
Intrinsic (de novo) and acquired endocrine resistance constitutes an important clinical challenge in the treatment of breast cancer and multiple mechanisms are suspected to underlie the emergence of endocrine resistance.
The role of the estrogen receptor (ER), encoded by the ESR1 gene, in normal mammary gland development and the progression of breast cancer is well established. ESR1 mutations, occurring in 10 to 30% of ER-positive metastatic breast cancer resistant to AIs, lead to ligand-independent activation of the ER.
For patients treated with AIs, monitoring of circulating tumour DNA (ctDNA) for ESR1, PIK3CA and AKT1 mutations could permit early detection of resistance to AIs as recently reported during 2016 American Society of Clinical Oncology (ASCO) meeting.
Who can participate
Age range
18 Years
Sex
FEMALE
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Female patient aged 18 and older
. Histologically confirmed estrogen-receptor-positive, HER2-negative breast cancer
. Proven metastatic (AJCC stage IV) or loco-regionally advanced (AJCC stage III) breast cancer, not amenable to surgery or radiation with curative intent.
. Indication to treat with first-line endocrine therapy for palliative care.
. Patients who can benefit from an additional blood sample of 10ml. The total volume of each sample meets with the indications of the Order in force establishing the list of researches mentioned in 2 ° of Article L. 1121-1 of the Public Health Code.
. Informed consent explained to, understood by and signed by patient. Patient must be given a copy of informed consent.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
. Patients affiliated to a social security scheme or benefit from a social regime
Exclusion criteria
. Pregnant or breast-feeding woman.
. Patient who received any prior systemic hormonal therapy for advanced breast cancer; no more than one prior regimen of chemotherapy for the treatment of advanced disease is allowed.
. Chemotherapy in combination with endocrine therapy.
. Targeted therapy, except CDK 4/6 inhibitor, in combination with endocrine therapy.
. Planned surgery or radiation with curative intent.
. Other active malignancy.
. Any concurrent severe and/or uncontrolled medical condition(s) which could compromise participation in the study.
. Patient whose general state and / or conditions do not permit the collection of the additional blood sample.