The association between conventional ultrasound and contrast-enhanced ultrasound appearances and pathological features in small breast cancer

OBJECTIVE: To investigate the association between ultrasound appearances and pathological features in small breast cancer. MATERIALS AND METHODS: A total of 186 small breast cancers in 186 patients were analyzed in this retrospective study from January 2015 to December 2019 according to pathological results. Forty-seven cases of axillary lymph node metastasis were found. All patients underwent radical axillary surgery following conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS) examinations. The association between ultrasound appearances and pathological features was analyzed using univariate distributions and multivariate analysis. Then, a logistic regression model was established using the pathological diagnosis of lymph node metastasis and biochemical indicators as the dependent variable and the ultrasound appearances as independent variables. RESULTS: In small breast cancer, risk factors of axillary lymph node metastasis were crab claw-like enhancement on CEUS and abnormal axillary lymph nodes on US. The logistic regression model was established as follows: (axillary lymph node metastasis) = 1.100 x (crab claw-like enhancement of CEUS) + 2.749 x (abnormal axillary lymph nodes of US) - 5.790. In addition, irregular shape on CEUS and posterior echo attenuation on US were risk factors for both positive estrogen receptor and progesterone receptor expression, whereas calcification on US was a risk factor for positive Her-2 expression. A specific relationship could be found using the following logistic models: (positive ER expression) = 1.367 x (irregular shape of CEUS) + 1.441 x (posterior echo attenuation of US) - 5.668; (positive PR expression) = 1.265 x (irregular shape of CEUS) + 1.136 x (posterior echo attenuation of US) - 4.320; (positive Her-2 expression) = 1.658 x (calcification of US) - 0.896. CONCLUSION: Logistic models were established to provide significant value for the prediction of pre-operative lymph node metastasis and positive biochemical indicators, which may guide clinical treatment.