Axillary Sentinel Lymph Node Biopsy After Neoadjuvant Chemotherapy in Patients With Initial cN1 Breast Cancer

SLNB has been recommended by domestic and foreign guidelines for patients with initial cN1 and NAC descending to ycN0. However, the best technical path is still not very clear at present, and the long-term tumor safety data is still insufficient. Therefore, it is necessary to further explore the optimal technical pathway and long-term tumor safety for SLNB in patients with initial cN1 and NAC downgrading to ycN0 in the real world.This study will evaluate the optimized technical pathway and long-term tumor safety of SLNB in patients with initial cN1 and NAC downgrading to ycN0 in real-world studies. The main endpoint of the study was axillary recurrence free survival. The secondary study endpoints were regional lymph node recurrence free survival, disease-free survival, overall survival, incidence of postoperative upper limb lymphedema, and patient quality of life.

Inclusion criteria

• Patients With ECOG Score 0-1 Points
• Patients With Breast Cancer Stage cT1-3N1M0 (According to AJCC Version 7) Pathological Diagnosis of Ipsilateral Axillary Lymph Node Metastasis in Patients With Invasive Breast Cancer
• Patients With Abnormal Axillary Lymph Nodes ≤ 3 Detected by Imaging Examination
• Patients With Effective Neoadjuvant Therapy (CR+PR)
• Patients With Clinical Axillary Negative ycN0 After Neoadjuvant Therapy
• Patients Without Prior History of Ipsilateral Axillary Surgery and Radiation Therapy
• Patients Without Previous History of Ipsilateral Breast Cancer (Including Carcinoma in Situ)
• Patients Without Obvious Contraindications for Surgery or Radiation Therapy
• No Other History of Malignant Tumors Within 5 Years From Enrollment in the Study
• Patients Who Participate in Other Clinical Trials at the Same Time and Are Judged by the Researchers Not to Affect the Study Protocol Can be Enrolled Normally
• The patient voluntarily joined this study and signed an informed consent form.

Exclusion criteria

• Stage IV (metastatic) breast cancer；
• Simultaneous double breast cancer；
• Baseline cT4;
• Baseline cN2-3
• gestation
• There are contraindications for SLNB;
• Suffering from serious comorbidities or other comorbidities that may interfere with the planned treatment, or any other circumstances in which the researcher deems the patient unsuitable to participate in this study