Ultrasonography and fine-needle aspiration cytology can spare breast cancer patients unnecessary sentinel lymph node biopsy

Background: Some 30% to 40% of the breast cancer patients scheduled for sentinel node biopsy have axillary metastasis. Pilot studies suggest that ultrasonography is useful in the preoperative detection of such nodes. The aims of this study were to evaluate the sensitivity of preoperative ultrasonography and fine-needle aspiration cytology for detecting axillary metastases and to assess how often sentinel node biopsy could be avoided. Methods: Between October 1999 and December 2003, 726 patients with clinically negative lymph nodes were eligible for sentinel node biopsy. A total of 732 axillae were examined. Preoperative ultrasonography with subsequent fine-needle aspiration cytology in case of suspicious lymph nodes was performed in all patients. The sentinel node procedure was omitted in patients with tumor-positive axillary lymph nodes in lieu of axillary lymph node dissection. Results: Ultrasound and fine-needle aspiration cytology established axillary metastases in 58 (8%) of the 726 patients. These 58 were 21% of the total of 271 patients who were proven to have axillary metastasis in the end. Of the patients with ultrasonographically suspicious lymph nodes and negative cytology, 31% had tumor-positive sentinel nodes. Patients with preoperatively established metastases by ultrasonography and fine-needle aspiration cytology had more tumor-positive lymph nodes (P < .001) than patients with metastases established later on. Conclusions: The sensitivity of ultrasonography and fine-needle aspiration cytology is 21%, and unnecessary sentinel node biopsy is avoided in 8% of the patients. This approach improves the selection of patients eligible for sentinel node biopsy.