Axillary staging by ultrasound-guided fine-needle aspiration cytology in breast cancer patients. Still up to date?

To investigate whether clinicopathological features of breast cancer patients could predict the likelihood of lymph node metastases and the likelihood of false-negative results of ultrasound-guided fine-needle aspiration cytology of suspicious lymph nodes (US+FNAC). Between 2004 and 2009, US+FNAC was performed in 1,150 axillae (18 bilateral breast carcinomas). Based on final histologic diagnosis, the true- and false-negative group of US+FNAC were defined. Subsequently, 11 clinicopathological factors were compared between these two groups. These factors were also compared between patients with and patients without lymph node metastases. Of 1,150 axillae, 429 had lymph node metastases at final histology. US+FNAC indicated metastases in 107 axillae. 1,043 axillae were negative by US+FNAC. Final histology showed metastases in 323 of these 1,043 axillae, resulting in a false-negative group of US+FNAC of 31%. Both age <60 years and a cT2/cT3 breast carcinoma were significantly associated with lymph node metastases and with false-negative results of US+FNAC. Lymph node metastases were found in 59.6% of patients <60 years with a cT2/cT3 breast carcinoma. In these patients, 52.3% of the negative US+FNAC results were falsely negative. In patients <60 years with a cT2/cT3 breast carcinoma, we recommend to omit US+FNAC preoperatively and perform a SNB directly, because lymph node metastases were found in 59.6% of these patients and 52.3% of negative US+FNAC results were falsely negative.