Abstract P3-03-20: Which biopsy is preferred to stage the axilla under ultrasound guidance in early breast cancer patients: Fine-needle aspiration cytology or core needle biopsy?

Abstract

Abstract Background: Preoperative axillary ultrasound (AUS) offers the potential to identify clinically axillary negative patients with axillary lymph node (ALN) metastasis directly to axillary lymph node dissection (ALND) with avoid of unnecessary sentinel lymph node biopsy (SLNB) except Z0011 candidates. Which biopsy should be preferred is pendent with lack of enough prospective studies. The purpose of our study was to compare the accuracy of ultrasound guided fine-needle aspiration cytology (FNAC) and core needle biopsy (CNB) for the designated ALN prospectively. Methods: Consecutive patients with histologically confirmed breast cancer from April, 2010 to December, 2014 were preliminary screened for our study. All the candidate patients were prospectively assessed by ipsilateral AUS before initial treatment regardless of clinical ALN status.Abnormal lymph nodes were characterized by round shape with uniform or eccentric thickening, focal bulging or irregularity of the cortex displacement, obliteration of the hilum; or total loss of recognizable lymph node architecture. If suspicious ALN was identified, both ultrasound-guided FNAC and CNB were performed for the same designated ALN.The diameter in longitudinal section, transverse section and maximum cortical thickness of the target node was recorded. When more than one abnormal lymph node was present, the most abnormal-appearing node was sampled. The target tissue for biopsy was hypoechoic thickened cortex. Patients with a positive FNAC/CNB underwent ALND, and those with a negative FNAC and CNB biopsy or without suspicious ALN by AUS underwent SLNB. The paired parameters of FNAC and CNB were compared using McNemar's exact test. Results: 705 consecutive patients were screened and 558 patients (561 axillae) underwent AUS evaluation with confirmed ALN pathological results.145 patients (146 axillae) with both FNAC and CNB were finally enrolled. Final histopathological results showed that 83.6% (122/146) were node positive (5 micro-metastases were considered negative). Sensitivity of FNAC and CNB was 67.2% (82/122) and 91.8% (112/122). Overall accuracy of FNAC and CNB was 72.6% (106/146) and 93.2% (136/146). Negative predictive value (NPV) of FNAC and CNB was 37.5% (24/64) and 70.6% (24/34). There was significant difference in sensitivity, overall accuracy and NPV between FNAC and CNB (p<0.001). 80.6% (29/36) FNAC negative and CNB positive patients have ALN cortical thickness of 3.3-7.2 mm. Conclusion: CNB is more sensitive and accurate than FNAC to stage the axilla under ultrasound guidance in operable breast cancer patients, especially in patients with ALN cortical thickness of 3.3-7.2 mm. Citation Format: Zhou M, Qiu J, Chen J, Hu Y, Deng Y, Zheng S. Which biopsy is preferred to stage the axilla under ultrasound guidance in early breast cancer patients: Fine-needle aspiration cytology or core needle biopsy? [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-20.