Dynamic Contrast-enhanced Magnetic Resonance Imaging for Patients with Breast Cancer Receiving First-line Bevacizumab and Paclitaxel.

BACKGROUND: Bevacizumab plus paclitaxel shows promise for metastatic disease; however, there is no predictive biomarker. Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) is widely used to evaluate the efficacy of anti-angiogenic therapies.

PATIENTS AND METHODS: Patients with locally advanced/metastatic breast cancer who had not received any prior chemotherapy or hormone therapy were included. DCE-MRI was conducted at baseline and after one and two cycles of bevacizumab and paclitaxel. The percentage change in the volume transfer constant (ΔKtrans) and the correlation of ΔKtrans with tumour regression and time to progression (TTP) were evaluated.

RESULTS: The mean ΔKtrans from baseline after one and two cycles was -51.4% and -55.1%, respectively. Patients with ΔKtrans ≥50% displayed more tumour regression than those with ΔKtrans <50%; TTP was not significantly different.

CONCLUSION: We demonstrate a decrease in blood permeability following bevacizumab and paclitaxel using DCE-MRI and a correlation between ΔKtrans and tumour regression.