Preoperative axillary ultrasonography in patients with breast cancer: a prospective study to evaluate its ability to predict axillary tumor load

Abstract

Objective: This study aimed to determine the ability of axillary ultrasonography to predict the number of lymph nodes with metastases found in sentinel node axillary surgery or axillary lymph node resection in patients recently diagnosed with breast cancer after percutaneous biopsy.

Methods: This prospective study included patients diagnosed with invasive breast cancer by percutaneous biopsy. Axillary lymph nodes were classified at ultrasound examination as suspicious or not suspicious, and the number of suspicious nodes was compared with the number classified as suspicious in the surgical specimen.

Results: We included 142 patients, 4 of whom had bilateral cancer; 133 of the 146 tumors were clinically classified as T1-T2 N0. The median number of suspicious lymph nodes at ultrasound was 2 (1-6), and the median number of suspicious lymph nodes in the surgical biopsy specimen was 1 (1-16); the difference was not significant (p = 0.1). The correlation between the number of positive lymph nodes on axillary ultrasound and the number of metastatic lymph nodes in the surgical specimen was 72.7% p = 0.0002 and the concordance was 79% (95%CI 62.4%-95.6%) p = 0.0001. For diagnosing high axillary tumor load (≥3 metastatic lymph nodes) versus low axillary tumor load (<3 metastatic lymph nodes), axillary ultrasound had 86.6% sensitivity, 83.3% specificity, 92% PPV, and 71.4% NPV.

Conclusion: Our results show that preoperative axillary ultrasound can differentiate between low and high tumor load and can be used as a tool to select the type of treatment. These results need to be confirmed in randomized multicenter studies.

Keywords: Axila; Axilla; Axillary staging; Axillary tumor load; Breast cancer; Carga tumoral axilar; Cáncer de mama; Etapificación axilar; Ultrasonido; Ultrasound.