Table 5. Cox's regression model for EGFR/MMP-9 coexpression.

Variable	Harzard ratio	95% CI	P-value
MMP-9
<20%	1.0		0.792
⩾20%	0.93	0.54–1.59
EGFR
<20%	1.0		0.015
⩾20%	0.52	0.31–0.88
MMP-9/EGFR coexpression
Negative	1.0		<0.001
Positive	3.55	1.73–7.26

EGFR=epidermal growth factor receptor; MMP-9=metalloproteinase-9; 95% CI=95% confidence intervals.