Correlation between Ultrasound Appearance of Small Breast Cancer and Axillary Lymph Node Metastasis

To study the correlation of ultrasonographic signs of small breast cancer (maximum diameter ≤2.0 cm) with axillary lymph node metastasis, pre-operative ultrasonographic images of 153 small breast malignant neoplasms in 143 breast cancer patients were analyzed according to their pathologic features. Of the small breast tumors included, 47 showed axillary lymph node metastasis. Diagnosis of all patients was obtained with radical axillary surgery or a sentinel lymph node biopsy procedure. Ultrasonographic signs included irregular shape, microlobulated contour, spiculation, microcalcification, posterior echo attenuation, blood-flow grade, perforating vessels, changes in fascia or cooper's ligament and maximum cortical thickness of lymph nodes. The relationship between ultrasonographic features and axillary lymph node metastasis was analyzed using a chi-square test for univariate distributions and logistic regression for multivariate analysis. A logistic regression model was established by taking the pathologic diagnosis of lymph node metastasis as the dependent variable and the ultrasonographic signs of each small breast cancer as independent variables. In small breast cancer, characteristics such as perforating vessels and maximum cortical thickness of lymph nodes >3.0 mm correlated well with axillary lymph node metastasis as determined by univariate analysis (χ² = 13.945, 51.276, respectively, p <0.05) and multivariate analysis (OR = 48.783, 46.754, respectively, p <0.05).