Ultrasound Imaging for Detecting Metastasis to Level II and III Axillary Lymph Nodes after Axillary Lymph Node Dissection for Invasive Breast Cancer

OBJECTIVES: The diagnostic value of axillary ultrasound (US) for level II and III axillary lymph node metastasis after axillary lymph node dissection for invasive breast cancer is currently not clear. The objectives of this study were to retrospectively analyze the diagnostic value of axillar US for level II and III axillary lymph node metastasis and compare it with palpation and to analyze the US features of level II and III axillary lymph nodes that are predictive of metastatic recurrence during follow-up. METHODS: Cases with level II or III axillary lymph nodes detected by US between January 2005 and December 2017 at a cancer center were divided into 2 groups according to a retrospective analysis of US findings: potential malignancy group and follow-up group. Biopsy was performed in all patients in the potential malignancy group. In the follow-up group, the patients were followed for at least 2 years, and biopsy was performed if suspicious US features were detected. RESULTS: The 401 enrolled cases were followed by axillary US and physical examination (PE) for comparison. Finally, 55 axillary metastases were pathologically confirmed (14%). The sensitivity, specificity, and area under the receiver operating characteristic curve for axillary US were 92.7%, 93.9%, and 0.933, respectively, and the corresponding values for PE were 49.1%, 91.3%, and 0.702 (P < .001). An increase in the major or minor axis diameter of the lymph nodes of greater than 2 mm, a Solbiati index value of less than 1.5, and the presence of new suspicious lesions in other regions were significant predictors of lymph node metastasis based on the US findings (P = .013, .006, .015, and .036). CONCLUSIONS: Axillary is helpful in the follow-up of level II and III axillary lymph nodes after axillary lymph node dissection for invasive breast cancer and can detect cancer recurrence earlier than PE.