False negative results in axillary lymph nodes by ultrasonography and ultrasonography-guided fine-needle aspiration in patients with invasive ductal carcinoma

Purpose: For preoperative evaluation of ALN status using various methods, axillary US and subsequent US-FNA targeting the LNs suspicious for metastasis are the most widely used methods. The purpose of our study was to assess the rate of false-negative results at preoperative ultrasonography (US) and ultrasonography guided fine needle aspiration (US-FNA) of axillary lymph nodes (ALNs) in breast cancer patients and the number of false-negative lymph nodes, and to evaluate factors related to ALN false negative results in US and/or US-FNA in patients diagnosed with invasive ductal carcinoma. Materials and Methods: Among 317 patients who underwent surgery for invasive ductal carcinoma during 2009 in Severance hospital, 237 patients had no reported ALN metastasis on preoperative US-FNA and US.We retrospectively reviewed the subsequent surgical pathology and clinicopathologic findings and assessed the rate of false-negative results from US and US-FNA of ALN and the number of false-negative lymph node. We performed univariate analysis and multivariate logistic regression analysis to evaluate the relationships between variable clinicopathologic factors (T-stage, position of ALN, hormone receptors, histologic grade, lymphovascular invasion (LVI) and performance of FNA) and cytologic results (false-negative result; FNALN and true negative result; TNALN) from US and/or US-FNA of ALN. Results: The rate of false-negative results was 42.4% (59/139) in both US and US-FNA of ALN but among them, 57.6% (34/59) showed only one metastatic ALN. Breast cancer with FNALN on US and US-FNA was significantly related to positive estrogen receptor (p=0.003), positive progesterone receptor (p=0.001), and the presence of LVI (p=0.004) in univariate analysis. In multivariate analysis, high T stages (≥T2, odds ratio (OR) 4.007, p=0.004) and LVI (OR 7.951, p=0.001) showed significant correlation with FNALN on US and US-FNA. Conclusion: More than half of patients with FNALN showed only one metastatic ALN. LVI and high T-stages were the most important factors attributed to FNALN on US and US-FNA in patients with invasive ductal carcinoma.