The Benefit of Routine Axillary Sonographic Assessment in cN0 Breast Cancer Patients

Axillary ultrasound (US) is often part of the routine assessment of the clinically negative axilla in primary breast cancer, which determines the extent of axillary surgery to be performed. This study aims to ascertain the burden of disease in the axilla of patients with a normal clinical examination (cN0) but with US detected metastatic axillary lymph nodes.

We retrospectively identified 345 female patients who underwent axillary lymph node dissection, following a positive lymph node biopsy, between January 2015 and August 2019.Eighty-nine of those had a positive biopsy prior to surgery. They were divided into two groups: Those with clinically palpable axillary disease preoperatively, cN1 (n = 41), and those with a normal clinical axillary examination, cN0 (n = 48). We assessed the number of positive axillary lymph nodes dissected in the two groups.

In the cN0 group the mean value of excised disease-positive axillary lymph nodes was 3.6, while in the cN1 group it was 8.0 (p<0.01). However, further analysis showed that 25 patients of the cN0 who had T1/T2 tumors had ≥3 positive lymph nodes.

Our study suggests that the presence of clinically palpable axillary lymph nodes appears to be correlated to a higher number of positive lymph nodes. However, in cases of non-palpable sonographically positive lymph nodes there might still be significant axillary disease, even in T1 and T2 tumors. Therefore we still support the routine use of preoperative sonographic assessment of the axilla for early breast cancer.