Exemption of SLNB After Neoadjuvant Therapy for Triple-negative and Her2-positive Breast Cancer

A Multicenter, Randomized Controlled Study on the Exemption of Sentinel Lymph Node Biopsy After Neoadjuvant Therapy for Triple-negative and Her2-positive Breast Cancer

The neoadjuvant system therapy (NAST) can significantly increase the pathological complete response (pCR) rate for patients with triple-negative (TNBC) and HER2-positive breast cancer. Some patients can achieve complete disappearance of the tumor or only residual tumors ≤ 2 cm in preoperative imaging examinations (mammography, ultrasound or MRI), which is defined as clinical complete response (cCR).

The traditional surgical approach still requires sentinel lymph node biopsy (SLNB) even for cCR cases to rule out axillary metastasis. However, the association of SLNB with complications such as lymphedema, pain, and limited shoulder joint function has been confirmed in multiple retrospective cohorts, significantly reducing the quality of life of patients.

Current guidelines (such as ASCO 2025, SOUND, INSEMA) propose that SLNB can be omitted in low-risk populations, but these recommendations are mainly based on postoperative pathological information (pCR) or overall survival (OS)/progression-free survival (DFS), and lack high-level evidence for the direct assessment of axillary lymph node recurrence rate (AR).

Therefore, there is an urgent need to conduct prospective, randomized controlled trials to clarify whether omitting SLNB will lead to an increase in axillary recurrence in T1-2 N0 triple-negative or HER2-positive breast cancer patients who achieve cCR after neoadjuvant treatment. The results of this study will provide evidence-based support for surgical de-radication, potentially significantly reducing surgical-related complications, saving medical resources, and improving the quality of life of patients.

Study Overview

• Status: Active, not recruiting
• Conditions: Breast Cancer; Breast Cancer (Triple Negative Breast Cancer (TNBC))
• Intervention / Treatment: Procedure: Exemption of SLNB

• Study Type: Interventional
• Enrollment (Actual): 216
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Xi'an, China
    • Xijing Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Female, aged 18 to 70 years;
2. Histologically diagnosed with invasive breast cancer, clinical stage T1-T2 (tumor maximum diameter ≤ 5 cm), clinical assessment as cN0 (physical examination + at least two negative imaging tests, including axillary ultrasound, and MRI or PET CT when necessary);
3. Immunohistochemistry or ISH confirmed as HER2 positive (IHC 3+ or ISH positive) or triple-negative (ER, PR, HER2);
4. Completed a standardized neoadjuvant chemotherapy regimen (including HER2-targeted or immune checkpoint inhibitors), and was assessed as clinical complete response (CCR) before surgery;
5. No residual masses on physical examination;
6. Imaging (MMG/US/MRI) shows the tumor ≤ 2 cm or complete disappearance;
7. Preoperative or intraoperative biopsy (when necessary) confirmed no residual invasive cancer.
8. ECOG 0-1, and expected to be able to receive whole breast radiotherapy after breast-conserving surgery.
9. Voluntarily signed a written informed consent.

Exclusion Criteria:

1. Tumor-related symptoms and treatment 1) Patients with metastatic breast cancer or bilateral breast cancer; 2) Patients with inflammatory breast cancer; 3) Patients with multiple lesion sites;

2. Comorbid diseases/medical history 1) Previously had other malignant tumors and received any systemic anti-tumor treatment or local treatment (including surgery and radiotherapy), excluding cured cervical carcinoma in situ, basal cell carcinoma or squamous cell carcinoma and other malignant tumors; 2) Within 4 weeks before enrollment, had undergone major surgeries unrelated to breast cancer or the patient had not fully recovered from such surgeries (biopsy for diagnostic purposes and peripheral venous puncture for central venous catheter insertion [PICC] are allowed); 3) Human immunodeficiency virus (HIV) infection or known acquired immune deficiency syndrome (AIDS); active hepatitis (hepatitis B, defined as HBV-DNA ≥ 500 IU/ml; hepatitis C, positive hepatitis C antibody and HCV-RNA above the detection limit of the analytical method) or co-infection with hepatitis B and hepatitis C; autoimmune hepatitis; 4) Previously or preparing to undergo allogeneic bone marrow transplantation or solid organ transplantation; 6) Severe heart disease or discomfort, including but not limited to the following diseases:

   • History of diagnosed heart failure or systolic dysfunction (LVEF < 50%)
   • High-risk uncontrolled arrhythmias, such as atrial tachycardia, resting heart rate > 100 bpm, significant ventricular arrhythmias (such as ventricular tachycardia) or higher-level atrioventricular conduction block (i.e. Mobitz II second-degree atrioventricular conduction block or third-degree atrioventricular conduction block)
   • Angina pectoris requiring anti-anginal drug treatment
   • Clinically significant heart valve disease
   • ECG showing transmural myocardial infarction
   • Poorly controlled hypertension (systolic pressure > 180 mmHg and/or diastolic pressure > 100 mmHg)
3. Pregnant or lactating female patients, female patients with reproductive capacity and positive baseline pregnancy test results or fertile women patients who are unwilling to take effective contraceptive measures throughout the trial period.
4. Previously had a clear history of neurological or mental disorders, including epilepsy or dementia, and the subjects were known to have a history of substance abuse of psychotropic drugs, alcoholism or drug abuse; Other conditions that the investigator considers make the patient unsuitable to participate in this study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Exemption of SLNB	Procedure: Exemption of SLNB; Breast-conserving surgery (or mastectomy) without sentinel lymph node biopsy (SLNB). Postoperatively, conventional radiotherapy (for breast-conserving therapy), endocrine (HR+) immunotherapy (for triple-negative cases), or HER2-targeted (HER2+) treatment is received.
No Intervention: Not Exemption of SLNB

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Efficacy Measurement	3-year AR (axillary recurrence rate): Axillary lymph node metastasis (stage I - III) confirmed by imaging (US/MRI/CT) or pathology within 3 years after surgery; not included in distant metastasis	3 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
DFS	The time from the subject's enrollment to the first occurrence of a recurrent disease. Recurrent diseases include recurrence on the same side or on the opposite side of the breast, local or regional recurrence, distant recurrence, and any death caused by	3 years
OS	The time from enrollment to death due to any cause.	3 years
Complications	Surgery-related complications (lymphedema, pain, limited shoulder function)	3 years
QLQ C30	Changes in European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire-Core 30 (QLQ C30). The assessment form consists of 30 items. Each item is scored from 1 to 4 points. The higher the score, the more severe the symptoms and the poorer the quality of life.	3 years
ICER	Cost-effectiveness (ICER)	3 years

Collaborators and Investigators

• Sponsor: Xijing Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2026
• Primary Completion (Estimated): December 31, 2030
• Study Completion (Estimated): March 1, 2031

Study Registration Dates

• First Submitted: March 16, 2026
• First Submitted That Met QC Criteria: March 23, 2026
• First Posted (Actual): March 27, 2026

Study Record Updates

• Last Update Posted (Actual): March 27, 2026
• Last Update Submitted That Met QC Criteria: March 23, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Skin Diseases; Breast Diseases; Skin and Connective Tissue Diseases; Breast Neoplasms; Triple Negative Breast Neoplasms
• Other Study ID Numbers: XJLL-KY-20262002

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No