To Evaluate the Accuracy of Axillary Staging Using Ultrasound and Ultrasound-Guided Fine-Needle Aspiration Cytology (USG-FNAC) in Early Breast Cancer Patients-a Prospective Study.

Abstract

In breast cancer, axillary lymph node involvement directly impacts the patient survival and prognosis. Sentinel lymph node biopsy (SLNB) is a procedure of choice for axillary staging in early breast cancer. Currently, management options for axilla management are axillary lymph node dissection and sentinel node biopsy in node positive and in node negative respectively. Accuracy of current clinical methods for evaluating axilla is low. Hence, to select patients for appropriate procedure, ultrasound (USG) combined with fine-needle aspiration cytology (USG-FNAC) using vascular pedicle-based nodal mapping method is emerging as a good tool to address above issues. We evaluated the feasibility of ultrasound and needle aspiration cytology in a tertiary care center. All early breast cancer patients with clinically node-negative axilla and having palpable nodes with less than or equal to 5cm tumor size in breast were screened by ultrasound of axilla to categorize the nodes as suspicious or non-suspicious based on radiological features and vascular pedicle-based nodal mapping method of axilla. Patients having suspicious nodes underwent ultrasound of axilla and needle aspiration; if found positive, patient underwent axillary node dissection. Sentinel node biopsy (SLNB) performed in all patients found negative on needle aspiration and in all patients having non-suspicious nodes on ultrasound axilla. Final histopathology was taken as gold standard. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were calculated for ultrasound (USG) and ultrasound-guided needle aspiration (USG-FNAC). A total of 100 patients were included in which 58 had non-suspicious and 42 had suspicious nodes on ultrasound of axilla. Among suspicious group, 24 were positive on ultrasound-guided needle aspiration cytology and 18 were negative. In non-suspicious nodes, sentinel node biopsy was performed. Sensitivity, specificity, positive predictive value, and negative predictive value for ultrasound were 61.5%, 75.6%, 69.5%, and 68.5% respectively. For ultrasound-guided needle aspiration (USG-FNAC), sensitivity, specificity, and positive and negative predictive value are 83%, 100%, 100%, and 72.6% respectively. The accuracy of ultrasound (USG) and ultrasound-guided needle aspiration (USG-FNAC) was 69% and 88.1%. The result of our study indicates the feasibility of USG and USG-FNAC in a high-volume center with good accuracy of around 70-80%. Approximately one-fourth (24%) of the total patients were taken up for axillary lymph node dissection (ALND) without performing SLNB.