Reduction of hormone therapy duration in women with hormonesensitive breast cancer at very low risk of metastatic recurrence

Prior treatment

• Patients who received a neo-adjuvant hormone therapy, a neo-adjuvant or adjuvant chemotherapy or preoperative medical treatment
• Contra-indications to the administration of anti-aromatase inhibitors

Other illness

• Any local or regional recurrence or metastatic disease
• Bilateral breast cancer (except in case of contralateral DCIS), or history of other invasive ipsi- or contralateral breast cancer
• Patients with a history of another malignancy without complete remission for more than 5 years, except for properly treated cervical carcinoma in situ and non-melanoma cancer of the skin
• Women with high-risk breast cancer predisposing deleterious germline mutations
• Patients with any other disease or illness, which requires hospitalization or is incompatible with the trial treatment

Other

• Patients unwilling or unable to comply with trial obligations for geographic, social, physical or psychological reasons, or who are unable to understand the purpose and procedures of the trial
• Persons deprived of their liberty or under protective custody or guardianship
• Non-invasive carcinoma
• Patients enrolled in another therapeutic study within 30 days of inclusion

• Postmenopausal women: Postmenopausal status is defined by any of the following: - Prior bilateral oophorectomy - Age ≥60 years - Age >50 and <60 years and amenorrheic for at least 12 months, and folliclestimulating hormone (FSH) and estradiol in the postmenopausal range
• IHC expression of the estrogen receptor and/or progesterone receptor ≥50%
• HER2 negative according to ASCO criteria in immunohistochemistry and/or genomic analysis (HER2 negativity is defined as IHC 0-1+, or [IHC 2+ and FISH or CISH nonamplified])
• No indication of adjuvant chemotherapy
• Patient considered has having a luminal A ultralow risk of metastatic recurrence (i.e. less than 5% risk of metastatic relapse at 10 years) according to MammaPrint® and Blueprint® tests.
• pT1 (tumor ≤20 mm), pN0, Grade 1 or Grade 2 OR pT2 (tumor ≤30 mm) and pN0, Grade 1 or Grade 2
• Patients eligible to receive or have recently started (with a maximum of 4 months of adjuvant hormone therapy prior to enrollment) an adjuvant hormone therapy (letrozole, anastrozole, or exemestane)
• Patient is willing and able to comply with the protocol for the duration of the study including scheduled visits, treatment plan, laboratory tests and other study procedures
• Patients must be affiliated to a Social Security System (or equivalent)
• Patient must have signed a written informed consent form prior to any trial specific procedures. When the patient is physically unable to give their written consent, a trusted person of their choice, independent from the investigator or the sponsor, can confirm in writing the patient’s consent
• Eastern Cooperative Oncology Group (ECOG) performance status 0-1
• Women with histologically proven invasive unilateral breast cancer
• M0: Not clinically nor radiologically detectable metastases at time of inclusion
• Primary tumor completely resected and adequate axillary surgery performed, according to current standards