SLNB Combined With WLNB for Axillary De-escalation in Breast Cancer Patients With Abnormal Axillary Nodes

Inclusion Criteria:

1. Female patients pathologically confirmed with primary invasive breast cancer via core needle biopsy;
2. Aged 18 years or older;
3. No enlarged lymph nodes palpable in the axilla on clinical examination; ultrasound reveals 1 or 2 abnormal ipsilateral axillary lymph nodes with malignant features (cortical thickening \>3 mm, hypoechoic, etc.), and at least one of them is confirmed metastatic by biopsy;
4. Maximum diameter of breast tumor ≤5 cm (cT1-2);
5. No distant metastasis detected on tumor staging examinations;
6. No prior neoadjuvant therapy received;
7. Sentinel lymph node biopsy combined with wire-localized lymph node biopsy completed by attending physicians per routine clinical practice;
8. Patients meet one of the following criteria for combined lymph node biopsy results and surgical management: total number of positive lymph nodes is 1-2 with breast-conserving surgery and omission of axillary lymph node dissection; or total number of positive lymph nodes is 1-2 with modified radical mastectomy; or total number of positive lymph nodes exceeds 2, with axillary lymph node dissection performed regardless of breast-conserving surgery or total mastectomy;
9. Voluntarily participating in this observational study and signing an informed consent form.

Exclusion Criteria:

1. Bilateral breast cancer;
2. Stage IV breast cancer;
3. Receipt of neoadjuvant therapy prior to surgery;
4. Previous ipsilateral axillary surgery history (e.g., osmidrosis surgery, lymph node biopsy) and history of axillary radiotherapy;
5. Coexistence of other malignant tumors within the past 5 years, excluding cured cutaneous squamous cell carcinoma, basal cell carcinoma, non-muscle invasive bladder cancer, cervical carcinoma in situ, breast carcinoma in situ, etc.;
6. Pregnant or lactating women;
7. Severe cardiac and pulmonary insufficiency precluding surgical tolerance.