[Hemodynamic changes in benign and malignant breast tumors and the mechanism]

To compare the histological morphology, hemodynamics and angiogenesis-related molecules between benign and malignant breast tumor and investigate their variation in different perfusion regions in the same type of tumors.

Thirty patients with malignant breast carcinoma and 30 with breast fibroadenoma underwent contrast-enhanced ultrasound examination with time-intensity quantitative analysis. The perfusion indices including peak intensity (PI), area under the curve (AUC), time to peak (TTP) and wash-out time (WOT) were measured both inside and on the margin of the foci. The expressions of CD34, vascular endothelial growth factor (VEGF), and Flk-1/KDR in both groups were measured immuhistochemically.

The time-intensity curve (TIC) of malignant tumor group was characterized by rapid ascent and slow descent, while that of the benign group presented with slow ascent and rapid descent. The AUC and WOT of the malignant tumor group were significantly higher than those of the benign group, while the PI and TTP showed no significant difference. In malignant tumor group, PI, AUC and WOT on the margin of the foci were significantly higher those of the inside region, while TTP showed a reverse pattern. No significant differences were found in the perfusion parameters between the inside and outside of the foci in the benign group. The distribution of CD34 was heterogeneous in breast carcinoma, and the micro-vessels were densely distributed especially on the margin of the cancer nest. The microvessel density of the malignant group (34.48-/+8.34) was significantly higher than that of the benign group (18.65-/+4.69). Diffuse or focal high VEGF expression was found on the margin of the cancer nest and necrotic tissue, but hardly detected in the benign group. Flk-1/KDR expressed diffusely or focally in breast carcinoma with especial high expression on the margin of the cancer nest and necrotic tissue, but was virtually undetectable in the benign group.

The perfusion pattern, TIC, mean perfusion parameter and variation of the regional perfusion parameters provide valuable evidence for differential diagnoses between benign and malignant breast tumors. Molecular imaging targeting VEGF and Flk-1/KD shed light on new approaches to early diagnosis of breast carcinoma.