Sentinel lymph node biopsy（SLNB） is an established way of predicting axillary nodal metastasis in early breast cancer. We aim to determinethe，in a prospective randomized, controlled trial, effect of sentinel lymph node biopsy with para-sentinel lymph node(SLN) dissection versus sentinel lymph node biopsy without para-sentinel lymph node dissection on outcomes after breast surgery.

Aim: Compare the disease-free survival (DFS) and overall survival (OS) of breast cancer patients who are randomized to receive sentinel lymph node biopsy with para-sentinel lymph node dissection group vs. those receive only sentinel lymph node biopsy without para-sentinel lymph node dissection

Outline:

Patients are randomized assigned to the following one of two groups and are followed annually.

Arm I: Patients receive sentinel lymph node biopsy with para-sentinel lymph node dissection Arm II: Patients receive only sentinel lymph node biopsy without para-sentinel lymph node dissection

Inclusion Criteria:

1. histologically confirmed primary breast cancer by core needle biopsy or excisional biopsy
2. abnormal para-sentinel lymph node was found by ultrasound examination
3. ultrasound-guided fine needle aspiration cytology of these nodes were performed
4. the result of fine needle aspiration cytology was negative (no tumour cell was found)
5. patient planed to perform SLNB

Exclusion Criteria:

1. pathological diagnosed ductal carcinoma in situ by excisional biopsy
2. the result of fine needle aspiration cytology was positive
3. patient has received neo-adjuvant system therapy