Preoperative assessment of the axilla by surgeon performed ultrasound and cytology in patients with breast cancer.

Background: Preoperative evaluation of the axilla, an important prognostic determinant for patients with invasive breast cancer, is achieved by non- or minimally invasive methods to avoid the potential hazards of operative intervention. The aim of this study was to determine statistical power of axillary ultrasound (US) and US-guided fine needle aspiration cytology (FNAC) for evaluating axillary status.

Methods: Axillary lymph nodes were imaged for malignant involvement by high resolution US in 93 breast cancer patients with clinically negative axilla. Cytological samples were obtained by US-guided FNAC from image-suspicious lymph nodes. Cytology-positive patients directly underwent axillary lymph node dissection (ALND). Patients with US and/or cytology-negative axilla underwent sentinel lymph node biopsy (SLNB). Using statistical analysis, US findings and US combined with FNAC were compared with SLNB and final pathology to measure performance.

Results: US was suspicious for metastasis in 38 patients (41%), of whom 16 (42%) were cytology-positive. Axilla was positive in 36/93 patients (38.7%). Sixteen patients with positive FNAC directly underwent ALND. SLNB and/or final pathology was positive in 13/55 patients (23.7%) with negative US (false negative of US) and in 7/22 patients (31.8%) with positive US but negative cytology (false negative of FNAC). SLNB and/or final pathology was negative in 15/38 patients (39.5%) with positive US (false positive of US). Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of US alone were 63.8%, 73.6%, 69.8%, 60.5% and 76.3%, respectively, and 69.6%,100%, 81.6%, 100% and 68.1%, respectively, for US combined with FNAC.

Conclusion: Statistical measures of the US alone did not achieve a satisfactory value for excluding operative biopsy. US-negative and US-positive but cytology-negative cases still require SLNB for accurate evaluation of axillary status. On the other hand, US-guided positive cytology can obviate SLNB proceeding directly to ALND and avoiding frozen section of sentinel node(s).