Comparative study of mutations in SNP loci of K-RAS, hMLH1 and hMSH2 genes in neoplastic intestinal polyps and colorectal cancer

Table 1 Clinical data of the three groups of patients

Group		Number	Sex (n)		Age (yr)
		(n)	Male	Female	Range	mean ± SD
Observation group (neoplastic polyps)	Tubular adenoma	85	54	31	27-68	39.2 ± 7.6
	Villous adenoma	17	9	8	24-65	36.5 ± 11.2
	Mixed adenoma	18	8	10	29-66	37.4 ± 10.9
Control group I (colorectal cancer)	Tubular adenocarcinoma	42	24	18	37-72	44.6 ± 11.3
	Mucinous adenocarcinoma	27	17	10	34-70	40.2 ± 9.6
	Papillary adenocarcinoma	8	5	3	33-58	41.1 ± 10.3
	Other types1	3	3	0	45-52	48.3 ± 7.1
Control group II (normal)		40	26	14	22-55	34.6 ± 6.3

¹Other types include undifferentiated carcinoma.

Table 2 Detection of target gene loci in the blood specimens of the observation group and the control groups I and II

	K-RAS-12		K-RAS-13		hMLH1-Va1384Asp		hMSH2-2783C/A
	+	-	+	-	+	-	+	-
Observation group	3	117	0	120	11	109	0	120
Control group I	15	65	18	62	10	70	7	73
χ2	15.476		29.670		0.568		10.811
P value	0.000		0.000		0.451		0.001
Control group II	1	39	0	40	1	39	0	40
χ2	0.000		-		10.486		-
P value	1.000		-		0.001		-

Table 3 Mutation rates of target genes in tissue specimens of the observation group and the control groups I and II

	K-RAS-12		K-RAS-13		hMLH1-Va1384Asp		hMSH2-2783C/A
	+	-	+	-	+	-	+	-
Observation group	7	113	1	119	19	101	3	117
Control group I	21	59	22	58	15	65	10	70
χ2	16.618		33.538		0.289		7.898
P value	0.000		0.000		0.591		0.005
Control group II	1	39	0	40	1	39	0	40
χ2	0.702		0.335		3.883		1.019
P value	0.361		0.750		0.048		0.419