Background: The sentinel lymph node biopsy (SLNB) procedure is the method of choice for the identification and monitoring of regional lymph node metastases in patients with breast cancer. In the case of a positive sentinel lymph node (SLN), additional lymph node dissection is still warranted for regional control, although 40-65 % have no additional axillary disease. Recent studies show that after breast-conserving surgery, SLNB, and adjuvant systemic therapy, there is no significant difference between recurrence-free period and overall survival if there are ≤2 positive axillary nodes. The purpose of this study was preoperative identification of patients with limited axillary disease (≤2 macrometastases) by using ultrasonography.
Methods: Data from 1,103 consecutive primary breast cancer patients with tumors smaller than 50 mm, no palpable adenopathy, and a maximum of 2 SLNs with macrometastases were collected. The variable of interest was US of the axilla.
Results: Of the 1,103 patients included, 1,060 remained after exclusion criteria. Of these, 102 (9.6 %) had more than 2 positive axillary nodes on ALND. Selected by unsuspected US, the chance of having >2 positive lymph nodes (LNs) is substantially lower (4.2 %). This is significant on univariate and multivariate analysis. After excluding the patients with extracapsular extension of the SLN, the chance of having >2 positive LNs is only 2.6 %. For pT1-2, this is 2.2 %.
Conclusions: The risk of more than 2 positive axillary nodes is relatively small in patients with cT1-2 breast cancer. US of the axilla helps in further identifying patients with a minimal risk of additional axillary disease, putting ALND up for discussion.