Evaluation of the combined role of axillary ultrasound with fine-needle aspiration cytology and sentinel lymph node biopsy in detecting axillary metastasis in clinically N0 axilla at tertiary care center Kerala

Abstract

Background: Sentinel lymph node biopsy (SLNB) is the gold standard for histopathological staging of early breast cancer. Combination of axillary ultrasound with fine-needle aspiration cytology (Ax US with FNAC) of suspicious lymph nodes, specificity for diagnosis of metastatic lymph nodes can be increased.Methods: This prospective study was done among 205 cases with clinically N0 axilla visited at surgical oncology department at Amrita institute of medical sciences from January 2014 to February 2017. Exclusion criteria was patients with locally advanced breast cancer, previous axillary surgery, prior breast irradiation, proven distant metastasis, inflammatory breast cancer and neo-adjuvant chemotherapy. All patients were subjected to ultrasound of breast and axilla during preoperative evaluation. Suspicious looking nodes were subjected to image guided FNAC. Benign appearing nodes or a negative FNAC, a SLNB procedure with intra-operative frozen section sentinel node (FS SN) was performed at the time of surgery.Results: Present study found sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of Ax US was 62.9%, 84.4%, 67.7%, 81.4% and 77.1% respectively. Sensitivity, specificity, PPV, NPV and accuracy of Ax US with FNAC was 90.0%, 100.0%, 100.0%, 83.3% and 93.3% respectively. Sensitivity, specificity, PPV, NPV and accuracy of SLNB with FS SN was 64.5%, 97.5%, 87.0%, 91.5% and 90.8% respectively.Conclusions: US guided fine-needle aspiration biopsy (FNAB) has highest specificity and sensitivity. Combining Ax US±FNAC and intra-operative FS SN in the detecting axillary metastasis very much decrease the chance of false results. The results of sonography would allow patients with sonographically positive axillae to be directed to axillary lymph node dissection (ALND). The remaining patients would be candidates for SN biopsy.