NIPH Clinical Trials Search

JCOG2402: A randomized phase III study of response-guided therapy in premenopausal patients with early breast cancer

Basic Information

Recruitment status	Recruiting
Health condition(s) or Problem(s) studied	ER-positive, HER2-negative invasive breast cancer
Date of first enrollment	27/01/2026
Target sample size	950
Countries of recruitment
Study type	Interventional
Intervention(s)	Arm A: Standard Treatment (Surgery + Postoperative Therapy) (1) Surgery - Breast: Breast-conserving surgery or mastectomy. - Axilla: Sentinel lymph node biopsy or axillary lymph node dissection. (2) Postoperative Therapy Based on pathological diagnosis of the surgical specimen and RS risk (Oncotype DX on biopsy specimen): - RS Low risk: Endocrine therapy alone (tamoxifen). - RS Intermediate risk: Endocrine therapy (TAM/AI+LHRHa) + chemotherapy (TC regimen). - RS High risk: Endocrine therapy (TAM/AI+LHRHa) + chemotherapy. In addition, radiotherapy, abemaciclib, or S-1 may be added depending on surgical procedure, pathological factors, and number of metastatic lymph nodes. Arm B: Experimental Treatment (Neoadjuvant Endocrine Therapy + Surgery + Postoperative Therapy) (1) Neoadjuvant Endocrine Therapy - AI + LHRHa for 12 weeks (TAM + LHRHa is available). (2) Surgery - Breast: Breast-conserving surgery or mastectomy. - Axilla: Sentinel lymph node biopsy or axillary lymph node dissection. (3) Postoperative Therapy Based on pathological diagnosis of the surgical specimen, RS risk (Oncotype DX on biopsy specimen), and ET response (Ki-67): - RS Low risk: Endocrine therapy alone (tamoxifen). - RS Intermediate risk: (a) Ki-67 <=10%: Endocrine therapy (TAM/AI + LHRHa). (b) Ki-67>10%, pN0: Endocrine therapy (TAM/AI + LHRHa) + chemotherapy (TC regimen). (c) Ki-67>10%, pN1: Endocrine therapy (TAM/AI + LHRHa) + chemotherapy. - RS High risk: Endocrine therapy (TAM/AI + LHRHa) + chemotherapy. In addition, radiotherapy, abemaciclib, or S-1 may be added depending on surgical procedure, pathological factors, and number of metastatic lymph nodes.

Outcome(s)

Primary Outcome	EFS:event-free survival
Secondary Outcome	Overall survival, Relapse-free survival, Distant metastasis-free survival, Proportion receiving postoperative endocrine therapy alone, Proportion receiving chemotherapy, ET response rate (Arm B), Incidence of adverse events, Incidence of serious adverse events, Non-deterioration proportion in HR-QOL, Proportion remaining premenopausal

Key inclusion & exclusion criteria

Age minimum	>= 18age old
Age maximum	Not applicable
Gender	Female
Include criteria	1. Histologically diagnosed as invasive breast cancer with ER-positive and HER2-negative. 2. Strong ER expression. 3. Invasive carcinoma >=2 mm on biopsy specimen. 4. Regarding nodal status (N), tumor size (T), and histological grade (HG), one of the following (i) or (ii) applies: (i) If cN0, any of the following (a)-(c): (a) HG 1: 3 cm < T <= 5 cm (b) HG 2: 2 cm < T <= 5 cm (c) HG 3: 1 cm < T <= 5 cm (ii)If cN1: T < 5 cm, and HG 1 or HG 2. 5. No distant metastasis on imaging. 6. No multiple lesions in the ipsilateral breast and no contralateral breast cancer. 7. Premenopausal female. 8. Age >=18 years. 9. ECOG Performance Status (PS) of 0 or 1. 10. No previous invasive or non-invasive breast cancer. 11. BRCA mutation not confirmed (testing not required). 12. No prior chemotherapy, endocrine therapy, or surgery for breast cancer (except endocrine therapy for menopausal symptoms, biopsy, or sentinel node biopsy). 13. No systemic anticancer therapy (including molecular targeted agents or immune checkpoint inhibitors) for other cancers within the last 5 years. 14. Recent blood tests (within 14 days) meet all of the following:: (i) Neutrophil count >=1,500/mm3 (ii) Hemoglobin >=9.0 g/dL (iii) Platelet count >=100,000/mm3 (iv) Total bilirubin <=1.5 mg/dL (v) AST <=100 U/L (vi) ALT <=100 U/L (vii) Serum creatinine <=1.5 mg/dL 15. Written informed consent obtained.
Exclude criteria	(1) Synchronous or metachronous (within 5 years) malignancies. (2) Infectious disease requiring systemic treatment. (3) Body temperature of 38 degrees Celsius or higher. (4) Female during pregnancy, within 28 days of postparturition, or during lactation. (5) Severe psychological disorder difficult to participate in this clinical study. (6) Receiving continuous systemic corticosteroid with a prednisolone equivalent greater than 10 mg/day or immunosuppressant treatment. (7) Uncontrollable diabetes mellitus. (8) Uncontrollable hypertension. (9) Unstable angina pectoris, or history of myocardial infarction within 6 months. (10) Uncontrollable valvular heart disease, dilated cardiomyopathy, or hypertrophic cardiomyopathy. (11) HBs antigen positive or HCV antibody positive (12) Pulmonary fibrosis or severe pulmonary emphysema based on chest CT.