Effectiveness of ultrasound in the detection of axillary metastasis in patients with breast cancer without clinical evidence of axillary disease: Clinical impact

Introduction: Preoperative ultrasound in patients with breast cancer without evidence of clinical axillary disease represents an attempt to reliably identify axillary lymph node metastasis. However, the usefulness of ultrasound for the detection of axillary disease should be evaluated. Materials and methods: The study included a retrospective cohort of 826 patients with diagnosed invasive breast cancer, treated at the National Cancer Institute of Mexico, from 2014 to 2018. All patients underwent ipsilateral axillary ultrasound for staging purposes. Besides the descriptive analysis of the preoperative ultrasound, findings of the cohort were compared with their corresponding cytology and histopathology reports. Results: Diagnostic index for axillary ultrasound was calculated as follows: 32.8% sensitivity, 82.5% specificity, 37.1% positive predictive value (PPV), 79.6% negative predictive value (NPV), 70.6% diagnostic accuracy, 1.86 positive likelihood ratio (LR+), and 0.81 negative likelihood ratio (LR−). Loss of fatty hilum was associated with a higher risk of axillary metastasis on the multivariate analysis (OR 3.645; 95% CI, 1.664–7.985, p < 0.001). Conclusions: The utility of axillary ultrasound as a method of determining the nodal status prior to surgery in patients with breast cancer without clinical evidence of axillary disease was not demonstrated in this study.