Quantitative evaluation of colorectal tumour vasculature using contrast-enhanced ultrasound: Correlation with angiogenesis and prognostic significance

Table 4 Multivariate analysis of prognostic factors for overall survival and disease-free survival

Prognostic factor	Hazard ratio (OS)	95%CI (OS)	P value (OS)	Hazard ratio (DFS)	95%CI (DFS)	P value (DFS)
VEGF expression	2.47	1.31-4.65	0.005	2.31	1.24-4.32	0.008
MVD	2.81	1.49-5.30	0.001	2.67	1.42-5.03	0.002
PI	2.55	1.36-4.78	0.003	2.38	1.28-4.42	0.006
TTP	2.34	1.24-4.41	0.008	2.26	1.20-4.26	0.011
AUC	2.62	1.38-4.96	0.003	2.54	1.34-4. 81	0.004

OS: Overall survival; DFS: Disease-free survival; CI: Confidence interval; VEGF: Vascular endothelial growth factor; MVD: Microvessel density; PI: Peak intensity; TTP: Time to peak; AUC: Area under the curve.