Bevacizumab (BV) is an antivascular endothelial growth factor antibody. When administered with other chemotherapeutic drugs, BV-combined regimens prolong survival of colorectal cancer patients. We conducted a phase II trial to confirm the pharmacokinetic parameters from 3-Tesla dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) as surrogate biomarkers of BV + FOLFIRI regimen efficacy in colorectal cancer with liver metastases. DCE-MRI was performed before treatment, on the seventh day after first treatment and every 8 weeks thereafter using a 3-Tesla MRI system. DCE-MRI parameters-area under the contrast concentration versus time curve at 90 and 180 s (AUC90 and AUC180, respectively) after contrast injection, and volume transfer constant of contrast agents (K(trans) and K(ep) ) were calculated from liver metastases. Fifty-eight liver metastases were analyzed. Univariate analysis revealed that a decrease in K(trans) ratios (ΔK(trans) ), K(ep) ratios (ΔK(ep) ), AUC90 ratios (ΔAUC90) and AUC180 ratios (ΔAUC180) correlated with higher response (all p < 0.0001) and longer time to progression (TTP) (ΔK(trans) : p = 0.001; ΔK(ep) : p = 0.004; ΔAUC90: p = 0.006; ΔAUC180: p < 0.0001). Multivariate analysis showed that ΔAUC180 was correlated with higher response (p = 0.009), and ΔK(trans) and ΔAUC180 were correlated with longer TTP (ΔK(trans) : p = 0.001; ΔAUC180: p = 0.024). ΔK(trans) and ΔAUC180 are pharmacodynamic biomarkers of the blood perfusion of BV + FOLFIRI. Our data suggest that ΔK(trans) and ΔK(ep) can predict response to chemotherapy at 1 week. Changes in 3-Tesla DCE-MRI parameters confirmed the potential of these biomarkers of blood perfusion as surrogate predictors of response and TTP.
Copyright © 2011 UICC.