De-escalation Therapy in Stage I ER-Positive Breast Cance... | NCT07153757

NCT07153757

Protocol Section

Identification Module

Results Section

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Annotation Section

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Document Section

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No data is available for this block.

Derived Section

Miscellaneous Info Module

Status Module

Arms/Interventions Module

Arm Groups

Label	Type	Description	Intervention Names
5 years of standard endocrine therapy	Active Comparator	The control group receives 5 years of standard endocrine therapy: Premenopausal patients: Tamoxifen (10 mg, orally, twice daily, for 5 years) or Toremifene (60 mg, orally, once daily, for 5 years); Postmenopausal patients: Letrozole (2.5 mg, orally, once daily, for 5 years) or Anastrozole (1 mg, orally, once daily, for 5 years) or Exemestane (25 mg, orally, once daily, for 5 years); A sequential regimen of 2-3 years of Tamoxifen or Toremifene followed by 3-2 years of Letrozole, Anastrozole, or Exemestane is acceptable. Ovarian function suppression is permitted for premenopausal patients. CDK4/6 inhibitors are not allowed during the treatment course	Drug: Endocrine Therapy of Physician's Choice
2-3 years of de-escalated endocrine therapy	Experimental	The experimental group receives 2-3 years of endocrine therapy: Premenopausal patients: Tamoxifen (10 mg, orally, twice daily, for 2-3 years) or Toremifene (60 mg, orally, once daily, for 2-3 years); Postmenopausal patients: Letrozole (2.5 mg, orally, once daily, for 2-3 years) or Anastrozole (1 mg, orally, once daily, for 2-3 years) or Exemestane (25 mg, orally, once daily, for 2-3 years). Ovarian function suppression is permitted for premenopausal patients. CDK4/6 inhibitors are not allowed during the treatment course.	Drug: Endocrine Therapy of Physician's Choice

Interventions

Name	Type	Description	Arm Group Labels	Other Names
Endocrine Therapy of Physician's Choice	Drug	This study employs a 2-3 year de-escalated endocrine therapy regimen in the experimental group, which distinguishes it from other escalation therapy studies.

Outcomes Module

Primary Outcomes

Measure	Description	Time Frame
5-year disease-free survival in the per-protocol population	The proportion of patients in a clinical trial who remained free of disease recurrence, secondary primary cancers, and death from the disease for five years following treatment initiation, calculated specifically among those who completed the study intervention as predefined in the trial protocol(i.e., without major deviations such as incomplete treatment, use of prohibited therapies, or significant protocol violations).	5 year

Secondary Outcomes

Measure	Description	Time Frame
5-year disease-free survival in the Full Analysis Set	The proportion of patients in a clinical trial who remained free of disease recurrence, secondary primary cancers, and death from the disease for five years after randomization or initiation of treatment, analyzed within the Full Analysis Set (FAS) population-which includes all subjects randomized (or initially assigned to a treatment group) following the intention-to-treat (ITT) principle, regardless of whether they fully received, discontinued, or deviated from the protocol.

Eligibility Module

Eligibility Criteria

Inclusion Criteria:

Females aged 18 years or older;
Postoperative pathological stage I early breast cancer: histologically confirmed invasive carcinoma with a maximum diameter ≤2 cm and node-negative (N0);
Immunohistochemistry (IHC) shows ER-positive (ER ≥50%), HER2 IHC score of 0, 1+, or 2+ with no amplification confirmed by FISH, and Ki-67 ≤20%;
Presence of at least one of the following potential low-risk factors:

1）Tumor size ≤1 cm, 2）21-gene recurrence score <11, 3）Fudan digital pathological subtype classified as SNF1, 4）Age ≥65 years;
ECOG performance status of 0 or 1;
Patients with bilateral synchronous invasive lesions are eligible if both lesions are ER-positive, HER2-negative, and meet the tumor size criteria;
Normal major organ function, meeting the following criteria:
1. Hematological: HB ≥90 g/L (no transfusion within 14 days), ANC ≥1.5×10⁹/L, PLT ≥100×10⁹/L;
2. Biochemical: TBIL ≤1.5×ULN, ALT and AST ≤3×ULN, serum Cr ≤1×ULN, and creatinine clearance >50 mL/min (Cockcroft-Gault formula);
Participants voluntarily enroll, sign informed consent, demonstrate good compliance, and cooperate with follow-up.

Exclusion Criteria:

Primary tumor size >2 cm in maximum diameter and/or axillary lymph node positivity;
Prior neoadjuvant therapy, any systemic therapy, or local therapy (except surgery), including chemotherapy, targeted therapy, radiotherapy, or endocrine therapy;
Prior adjuvant chemotherapy;
Use of CDK4/6 inhibitors in the adjuvant setting;
History of other malignancies (except cured basal cell carcinoma or cervical carcinoma in situ);
Metastasis at any site;
Pregnancy, lactation, or women of childbearing potential unable to use effective contraception;
Concurrent participation in other clinical trials;
Severe cardiac, pulmonary, hepatic, or renal dysfunction; LVEF <50% (by echocardiography); severe cardio-cerebrovascular diseases within 6 months (e.g., unstable angina, chronic heart failure, uncontrolled hypertension >150/90 mmHg, myocardial infarction, or stroke); poorly controlled diabetes; severe hypertension;
Severe or uncontrolled infections;
History of drug abuse or psychiatric disorders;
Patients deemed unsuitable for the study by the investigator.