Table 3.

Clinical variables of the colorectal cancer and their association with the rs712 polymorphism of KRAS gene

Clinical variable *	Genotype	Model	Allele	OR	Confidence intervals (95%)	P -value
Location: colon versus recto			T	3.82	(2.77-5.28)	0.0001
			G	0.26	(0.18-0.36)	0.0001
Node metastasis: positive	TT			2.49	(1.45-4.28)	0.0009
		recessive		0.40	(0.23-0.68)	0.0011
Differentiation: poor	GT			2.35	(1.35-4.1)	0.0033
**poor chemotherapy response	GT			2.6	(1.7-4.24)	0.0001

^*Non-significance clinical variables in analysis included: gender (male, female), age (<50, ≥ 50 years), tobacco and alcohol consumption, stage (I-II, III-IV), metastasis .

^** non-response to treatment with pro-drug 5-floururacil (5-FU) and capecitabine was evaluated according to the pathological Ryan's classification described as follows: 1. moderate response (single cells or small groups of cancerous cells), 2. minimum response (residual cancer surrounded by fibrosis), and 3. poor response (minimal or no tumor destruction, extensive residual cancer) (26).