Flow index of 3D breast ultrasound was strongly correlated with axillary lymph node metastasis in the absence of lymphovascular invasion

Axillary lymph nodes (ALN) are the most commonly involved site of disease in breast cancer that has spread outside the primary lesion. Many efforts had been made to try to predict ALN by using ultrasound, CT, MRI, even PET but it still inconclusive. Although sentinel node biopsy is a reliable way to management ALN; there have no good predictor methods for ALN status before surgery so far. We applied three indices, the vascularization index (VI), flow index (FI) and vascularization flow index (VFI) of 145 malignant 3D power Doppler breast ultrasound images and their tumorbiological parameters including age, tumor size, grade, ER, PR, lymphovascular invasion and HER2 to analyze regarding their correlations with axillary lymph node involvement in invasive breast cancer patients. Independent t tests, Pearson chi-squared tests, Pearson correlation and univariate logistic regression analyses were performed on all study patients. Characteristics of pathologic parameters and vascular features of breast cancer patients showed that only tumor volume, lymphovascular invasion and tumor grade were correlated with axillary lymph nodes metastases. While in univariate logistic regression of vascular features in negative lymphovascular invasion (N = 83) of breast cancer patients between negative and positive axillary lymph node metastases showing that FI was the strongest factor. This is the first study to show that flow index is strong correlated with axillary lymph node metastases in the absence of lymphovascular invasion.