Table 3.

Tumor growth pattern in colorectal cancer and patient mortality

		Colorectal cancer-specific mortality				Overall mortality
Tumor growth pattern	Total N (%)	No. of events	Univariate HR (95% CI)	Stage- stratified HR (95% CI)	Multivariate stage- stratified HR (95% CI)	No. of events	Univariate HR (95% CI)	Stage- stratified HR (95% CI)	Multivariate stage- stratified HR (95% CI)
Expansile	372 (33%)	64	1 (referent)	1 (referent)	1 (referent)	134	1 (referent)	1 (referent)	1 (referent)
Intermediate	610 (54%)	149	1.51 (1.13-2.03)	1.22 (0.90-1.64)	1.23 (0.91-1.67)	282	1.41 (1.14-1.73)	1.27 (1.03-1.58)	1.30 (1.04-1.62)
Infiltrative	157 (14%)	95	5.37 (3.90-7.40)	1.95 (1.38-2.75)	1.74 (1.22-2.47)	112	3.64 (2.82-4.69)	1.91 (1.44-2.54)	1.78 (1.33-2.39)
p for trend			<0.0001	0.0002	0.0021		<0.0001	<0.0001	0.0002

The multivariate, stage-matched (stratified) Cox regression model initially included the tumor growth pattern variable (expansile, intermediate, or infiltrative), age, sex, year of diagnosis, body mass index, tumor location, tumor differentiation, family history of colorectal cancer in any first degree relative, microsatellite instability, CpG island methylator phenotype, LINE-1 methylation, KRAS, BRAF, PIK3CA, tumor differentiation, mucinous component, signet ring cell component, and peritumoral lymphocytic reaction. A backward elimination with threshold of p=0.20 was used to select variables in the final models.

CI, confidence interval; HR, hazard ratio.