Table 4.

Univariate and Multivariate Cox Regression Analysis of miR-21 Expression Levels and Overall Cancer Survival in Subjects With Colon Adenocarcinoma^a

	Univariate Analysis		Multivariate Analysisb
Characteristic	HR (95% CI)	P Value	HR (95% CI)	P Value
Maryland Test Cohort
miR-21 expression (n=71)c
Low	1.0 [Reference]	.01	1.0 [Reference]	.008
High	2.5 (1.2-5.2)		2.7 (1.3-5.5)
TNM stage
I-II	1.0 [Reference]	.002	1.0 [Reference]	.002
III-IV	3.5 (1.6-7.9)		3.7 (1.6-8.3)
Age at enrollment, y
<50	1.0 [Reference]	.52
≥50	0.7 (0.2-2.3)
Sex
Women	1.0 [Reference]	.57
Men	1.4 (0.5-3.9)
Race
White	1.0 [Reference]	.97
Black	1.0 (0.5-2.1)
Tumor location (proximal/distal)
Distal	1.0 [Reference]	.26
Proximal	0.6 (0.3-1.4)
Hong Kong Validation Cohort
miR-21 expression (n=103)c
Low	1.0 [Reference]	.002	1.0 [Reference]	.002
High	2.4 (1.4-3.9)		2.4 (1.4-4.1)
TNM stage
I-II	1.0 [Reference]	<.001	1.0 [Reference]	<.001
III-IV	4.7 (2.4-9.5)		4.7 (2.4-9.5)
Age at enrollment, y
<50	1.0 [Reference]	.14
≥50	1.5 (0.9-2.6)
Sex
Women	1.0 [Reference]	.29
Men	1.4 (0.8-2.3)
Tumor location
Distal	1.0 [Reference]	.27
Proximal	0.7 (0.3-1.4)

Abbreviations: CI, confidence interval; HR, hazard ratio.

^aCases with mucinous adenocarcinoma, adenosquamous carcinoma, or signet ring cell carcinomas were excluded from this analysis.

^bMultivariate analysis used stepwise addition and removal of clinical covariates found to be associated with survival in univariate models (P < .10) and final models include only those covariates that were significantly associated with survival (Wald statistic, P < .05). For both final models, only miR-21 expression and TNM staging were included.

^cHigh expression in tumors for all miRNAs was defined based on the highest tertile. MicroRNA expression was measured with miRNA microarrays for the Maryland cohort and with quantitative reverse transcription polymerase chain reaction with the Hong Kong cohort.