Quantitative ultrasound as a predictor of node metastases and prognosis in patients with breast cancer

A retrospective study was performed to determine whether preoperative quantitative ultrasound assessment could predict axillary lymph node metastases and prognosis in patients with breast cancer. We focused on the presence of a halo, which is one of the features of breast cancer on ultrasound and represents reflections from the invading margin around infiltrating malignancies.

We evaluated ultrasonography from 187 infiltrating breast carcinoma patients with tumors 5 cm or less in greatest dimension (T1, T2). Using computer image analysis, the halo area (H) and the sum of the area of halo and internal echo (total tumor area (T)) were measured, and the ratio of halo to entire tumor (H/T, halo ratio) was calculated and compared with lymph node status and prognosis.

The mean of the halo ratio was 0.38+/-0.13. Using the value of 0.42 as a cut-off, the high halo ratio group had significantly worse prognoses for both overall and disease-free survival at 49 months in median follow-up (p <0.001 and p <0.0005, respectively). The specificity of a high halo ratio in the T1 classification for predicting axillary node metastasis was 83.1%, with a negative predictive value of 86.8%. In patients with tumors 1.0 cm or smaller, the negative predictive value was 100%. In a multivariate analysis, halo ratio was an independent predictor of disease-free survival of breast carcinoma patients (p =0.0232).

Preoperative quantitative ultrasound may be a useful non-invasive method for predicting the presence of axillary lymph node metastases and prognosis in patients with primary breast cancer.