EXEMESTANE for Early breast cancer | Hormone receptor-positive HER2-negative breast cancer | Luminal A breast cancer

Inclusion criteria

• {"criterion_text":"- Postmenopausal (underwent bilateral oophorectomy or non-chemo induced amenorrhea for 12 or more months) female participant ≥60 years of age.\n- The participant is willing and able to comply with the protocol for the duration of the study, including scheduled visits, treatment strategy, laboratory tests and other study procedures.\n- Participants must be affiliated with a Social Security System (or equivalent).\n- The participant must have signed a written informed consent form before any trial-specific procedures. When the participant is physically unable to give written consent, an impartial witness of her choice, independent from the investigator or the sponsor, can confirm the participant’s consent in writing.\n- New diagnosis of invasive carcinoma of the breast (ductal, tubular or mucinous) with primary tumor ≤1 cm on microscopic exam (pT1a-b), with no evidence of nodal or distant metastatic disease.\n- Contralateral breast described as BI-RADS 1 or 2 in diagnostic imaging.\n- Negative axillary node involvement by sentinel node biopsy or axillary node dissection (pN0). or Clinically negative axillary node involvement (cN0) after mandatory ultrasound exploration without surgical exploration of the axilla if BCS was performed.\n- ER positive (≥ 50%) and PR positive (> 20%), Ki67 low (≤15%) and HER2 negative (IHC or In Situ Hybridization approach) according to ASCO criteria.\n- Histological grade scored on the invasive component, 1 or 2 if pT1a or grade 1 if pT1b.\n- Treated by mastectomy or BCS with microscopically clear resection margins defined as “no-ink on tumor” or ≥1 mm for invasive and non-invasive disease or no residual disease on re-excision.\n- If BCS was performed, participants must have received or have scheduled adjuvant local radiotherapy within 3 months after surgery, as follows : - whole breast adjuvant radiotherapy, - with appropriate fractionation (15, 5, 16 or 25 fractions), as per current standards - with or without a boost to the tumor bed, - delivered in a sequential or simultaneous manner, as per radiation oncologist’s choice. - whole breast irradiation volumes will be defined as per current guidelines\n- No indication of adjuvant chemotherapy."}

Exclusion criteria

• {"criterion_text":"- Have received any neo-adjuvant treatment, including hormone therapy and chemotherapy.\n- History of non-breast cancer malignancies if not disease-free for > 5 years and considered low risk of recurrence except for treated carcinoma in situ of the cervix, endometrium or colon, melanoma in situ and basal or squamous cell carcinoma of the skin.\n- Non-malignant severe disease associated with a life expectancy < 10 years.\n- Women with BRCA1, BRCA2 or other high-risk breast cancer predisposing deleterious germline mutations.\n- Enrolled in another therapeutic study within 30 days prior to inclusion.\n- Unwilling or unable to comply with the medical follow-up required by the trial because of geographic, familial, social, or psychological reasons.\n- Persons deprived of their liberty or under protective custody or guardianship.\n- Have received or are eligible for adjuvant chemotherapy.\n- Absolute contraindication for RT in case of BCS or patients who were treated with partial breast irradiation.\n- Have been treated with mastectomy and with adjuvant radiotherapy received or scheduled.\n- Invasive lobular breast cancer.\n- Bilateral breast cancer or history of other invasive ipsi- or contralateral breast cancer.\n- Multifocal or multicentric disease.\n- Disease limited to microinvasion only (< 1 mm).\n- Evidence of lymphovascular invasion."}

Primary endpoints

• {"endpoint_text":"- Relapse-free interval (RFI) is defined as the delay between initial treatment and the first occurrence of i) ipsilateral breast tumor recurrence, ii) distant or locoregional recurrence or iii) death from breast cancer, according to the STEEP system definition version 2.0 (Tolaney SM et al., JCO 2021)","definition_or_measurement_approach":"RFI defined per STEEP system version 2.0: time from initial treatment to first occurrence of ipsilateral breast tumor recurrence, distant or locoregional recurrence, or death from breast cancer (Tolaney SM et al., JCO 2021)."}

Secondary endpoints

• {"endpoint_text":"- RFI of participants treated with adjuvant hormone therapy in the CANTO study","definition_or_measurement_approach":"Relapse-free interval (RFI) measured in the external CANTO cohort for comparison purposes."}
• {"endpoint_text":"- Incidence of Ipsilateral DCIS, Contralateral DCIS, Invasive contralateral breast cancer at 5, 8 and 10 years*, Distant disease free survival (DDFS) and relapse free survival (RFS) rates at 5, 8, 10 years and overall survival (OS) at 5, 10 years * (RFI, DDFS, RFS and OS defined as per standardized STEEP v2.0 criteria)","definition_or_measurement_approach":"Incidence and survival outcomes assessed at specified timepoints (5, 8, 10 years) with RFI, DDFS, RFS and OS defined according to standardized STEEP v2.0 criteria."}
• {"endpoint_text":"- EORTC QLQC30 and EORTC QLQ-BR42, HADS questionnaires","definition_or_measurement_approach":"Health-related quality of life measured using EORTC QLQ-C30, EORTC QLQ-BR42 and HADS instruments as specified in protocol."}
• {"endpoint_text":"- Bone-related events and osteopenia/osteoporosis diagnosis, dyslipidemia (hypercholesterolemia and hypertriglyceridemia) and cardiovascular events (myocardial infarction, stroke, and thromboembolic events), as per CTCAE v6.0.","definition_or_measurement_approach":"Adverse events and diagnoses captured and graded according to CTCAE v6.0; includes bone events, metabolic and cardiovascular events."}

France

Earliest CTIS Part Ii Submission Date

13-03-2026

Latest Decision Or Authorization Date

21-04-2026

Processing Time Days

39

Number Of Sites

42

Number Of Participants

630

Primary sponsor

Full Name

Unicancer

Organisation Type

Hospital/Clinic/Other health care facility

Country Of Registered Address

France