Clinical significance of MLH1/MSH2 for stage II/III sporadic colorectal cancer

Table 1 Name of primers, location, and the sequence of microsatellite instability

SNP	Location	Primer sequence
BAT26	2p16	p1 TGACTACTTTTGACTTCAGCC
		p2 AACCATTCAACATTTTTAACCC
D2S123	2p21-2p16	p1 AAACAGGATGCCTGCCTTTA
		p2 GGACTTTCCACCTATGGGAC
D5S346	5q21-5q22	p1 ACTCACTCTAGTGATAAATCGGG
		p2 CAGATAAGACAGTATTACTAGTT
BAT25	4q12	p1 TCGCCTCCAAGAATGTAAGT
		p2 TCTGCATTTTAACTATGGCTC
D17S250	17q11.2-17q12	p1 GGAAGAATCAAATAGACAAT
		p2 GCTGGCCATATATATATTTAAACC

SNP: Single nucleotide polymorphism.

Table 2 Relationship between clinicopathological features and MutL homolog1/MutS homolog2 expression in 681 patients, n (%)

Observation	Positivea	Negativeb	Total	χ2	P value
Gender
Male	310 (80.10)	77 (19.90)	387	0.252	0.625
Female	240 (81.63)	54 (18.37)	294
Age (yr)
≤50	63 (88.73)	8 (11.27)	71	3.240	0.072
>50	487 (79.84)	123 (20.16)	610
Location in the colon
Left	138 (82.14)	30 (17.86)	168	4.746	0.029
Right	119 (72.12)	46 (27.88)	165
Location of tumor Colon	257 (77.18)	76 (22.82)	333	5.395	0.025
Rectum	293 (84.20)	55 (15.80)	348
Grade of differentiation
Poor	28 (66.67)	14 (33.33)	42	5.725	0.017
Well-moderate	522 (81.69)	117 (18.31)	639
Tumor stage (TNM)
II	324 (82.03)	71 (17.97)	395	0.964	0.327
III	226 (79.02)	60 (20.98)	286
Tumor size (cm)
≤4	210 (78.95)	56 (21.05)	266	0.927	0. 370
>4	340 (81.93)	75 (18.07)	415
Lymphocytic infiltration
None or little	336 (82.76)	70 (17.24)	406	1.195	0.332
Marked or moderate	214 (75.76)	61 (27.24)	275
Mucin
Positive	108 (73.97)	38 (26.03)	146	5.517	0.024
Negative	442 (82.62)	93 (17.38)	535
Circumscribed margin
Negative	482 (79.80)	122 (20.20)	604	3.184	0.090
Positive	68 (88.31)	9 (11.69)	77

^aMLH1/MSH2 positive;

^bMLH1/MSH2 negative. MLH1: MutL homolog 1; MSH2: MutS homolog 2.

Table 3 Prognostic factors for survival in univariate and multivariate analyses

Observation	Univariate			Multivariate
	P	HR	95%CI	P	HR	95%CI
Model 1a
Gender
Male vs Female	0.932	0.984	0.684-1.417	0.991	0.998	0.685-1.454
Age/yr
≤50 vs >50	< 0.001	0.288	0.189-0.438	0.025	0.508	0.213-0.995
Location in the colon
Left vs Right	0.730	1.086	0.678-1.740	0.440	1.211	0.745-1.967
Location of tumor
Rectum vs Colon	0.232	1.311	0.840-2.047	0.017	1.795	1.111-2.902
Differentiation
Poor vs Well-moderate	0.002	0.426	0.472-0.734	0.923	0.972	0.542-1.741
Tumor stage
II vs III	0.034	0.651	0.437-0.968	0.041	0.601	0.321-0.932
Tumor size
<4 vs ≥4 cm	0.646	0.921	0.647-1.311	0.421	0.861	0.598-1.240
Lymphocytic infiltration
Positive vs Negative	< 0.001	2.282	1.092-5.756	0.022	3.665	1.207-7.128
Mucin
Positive vs Negative	0.001	2.361	1.647-3.383	< 0.001	2.512	1.714-4.682
Circumscribed margin
Positive vs Negative	< 0.001	3.908	2.654-5.755	0.011	2.474	1.433-4.270
MLH1/ MSH2
Positive vs Negative	< 0.001	3.799	2.205-6.546	< 0.001	4.064	2.241-7.369
Model 2b
Gender
Male vs Female	0.761	0.896	0.441-1.821	0.207	0.622	0.298-1.300
Age/yr
≤50 vs >50	< 0.001	0.150	0.075-0.302	< 0.001	0.131	0.063-0.271
MLH1/ MSH2
Positive vs Negative	0.014	4.833	1.382-16.899	0.011	5.583	1.478-21.092
Therapeutic regimen
Operation vs Operation + Chemotherapy	0.176	0.821	0.520-1.233	0.063	0.901	0.899-2.312
Model 3c
Gender
Male vs Female	0.964	0.990	0.647-1.517	0.748	0.932	0.607-1.432
Age/yr
≤50 vs >50	0.002	0.424	0.247-0.728	0.004	0.446	0.258-0.769
MLH1/ MSH2
Positive vs Negative	0.041	1.625	1.042-2.803	0.023	2.289	1.270-4.125
Therapeutic regimen
Operation vs Operation + Chemotherapy	0.028	2.891	1.209-6.372	< 0.001	4.002	1.929-9.425

^aAll 681 patients;

^b395 Patients with stage II CRC;

^c286 Patients with stage III CRC. HR: hazard ratio; CI: confidence interval; CRC: Colorectal cancer; MLH1: MutL homolog 1; MSH2: MutS homolog 2.

Table 4 Predictive factors for survival in univariate and multivariate analyses

Observation	Univariate			Multivariate
	P	HR	95%CI	P	HR	95%CI
Model 1a
MLH1/MSH2 negative
Operation vs Operation + Chemotherapy	0.098	1.021	0.342-2.741	0.147	1.563	0.481-4.441
MLH1/MSH2 positive
Operation vs Operation + Chemotherapy	0.081	1.899	0.127-4.114	0.070	1.267	0.212-5.052
Model 2b
MLH1/MSH2 negative
Operation vs Operation + Chemotherapy	0.001	4.393	2.068-12.316	< 0.001	7.660	2.974-15.883
MLH1/MSH2 positive
Operation vs Operation + Chemotherapy	0.063	2.015	0.648-5.997	0.052	2.817	0.223-6.671

^a395 Patients with stage II CRC;

^b286 Patients with stage III CRC. HR: hazard ratio; CI: confidence interval; MLH1: MutL homolog 1; MSH2: MutS homolog 2.