Association between IRS-2 G1057D polymorphism and risk of gastric cancer

Table 1 Demographic information n (%)

Characteristics	Cases (n = 197)	Controls (n = 156)	P value
Gender (male)	152 (77.16)	118 (75.64)	0.739
Age1 (yr)	60 (50-67.5)	58 (47.25-65)	0.197
Weight1 (kg)	62 (55-70)	67 (60-73.25)	0.001
Hypertension	43 (21.83)	29 (18.83)	0.490
Diabetes	10 (5.08)	14 (9.03)	0.144
Smoking	44 (22.34)	26 (16.67)	0.205
Residence
Rural	84 (42.64)	70 (45.45)	0.598
Urban	113 (57.36)	84 (54.55)

¹Median (25th-75th percentiles).

Table 2 Distribution of the IRS-2 genotype in cases and controls and risk estimates n (%)

IRS-2 genotype	Cases1	Controls1	Crude OR (95% CI)	P value	Adjusted OR2 (95% CI)	P value
Overall	197	156
GG	69 (35.02)	64 (41.03)	1.00		1.00
GD	98 (49.75)	82 (52.56)	1.11 (0.71-1.74)	0.653	0.96 (0.60-1.53)	0.864
DD	30 (15.23)	10 (6.41)	2.78 (1.26-6.15)	0.011	2.32 (1.03-5.23)	0.042
GD + DD	128 (64.98)	92 (58.97)	1.29 (0.84-1.99)	0.248	1.11 (0.71-1.75)	0.637
G allele	236 (59.90)	210 (67.31)	1.00
D allele	158 (40.10)	102 (32.69)	1.38 (1.01-1.88)	0.043

¹Distribution of the insulin receptor substrate-2 (IRS-2) genotype in cases and controls were in Hardy-Weinberg equilibrium (P = 0.204, P = 0.425, respectively);

²Adjusted for age, sex, smoking status, residence, hypertension and diabetes. OR: Odds ratio.

Table 3 Stratified analyses for variant IRS-2 genotypes in cases and controls n (%)

Variable	(GD + DD)/GG		Crude OR (95% CI)	P value	Adjusted OR1 (95% CI)	P value
	Cases	Controls
Age (median) (yr)
≤ 58	53 (26.9)/40 (20.3)	46 (29.5)/39 (25.0)	1.29 (0.71-2.33)	0.412	1.10 (0.59-2.05)	0.762
> 58	69 (35.0)/35 (17.8)	46 (29.5)/25 (16.0)	1.22 (0.64-2.32)	0.538	1.15 (0.60-2.23)	0.674
Sex
Females	28 (14.2)/17 (8.6)	21 (13.5)/17 (10.9)	1.33 (0.55-3.21)	0.521	1.13 (0.44-2.87)	0.800
Males	94 (47.7)/58 (29.4)	71 (45.5)/47 (30.1)	1.27 (0.77-2.10)	0.342	1.12 (0.67-1.87)	0.668
Smoking status
Smokers	32 (16.2)/12 (6.1)	16 (10.4)/10 (6.5)	1.88 (0.66-5.33)	0.238	1.52 (0.49-4.70)	0.467
Non-smokers	90 (45.7)/63 (32.0)	75 (48.7)/53 (34.4)	1.16 (0.72-1.87)	0.550	1.00 (0.61-1.65)	0.990
Residence
Urban	73 (37.1)/40 (20.3)	51 (33.1)/33 (21.4)	1.44 (0.80-2.61)	0.226	1.30 (0.70-2.42)	0.406
Rural	49 (24.9)/35 (17.8)	41 (26.6)/29 (18.8)	1.04 (0.55-1.98)	0.905	0.89 (0.46-1.75)	0.743

¹Adjusted for age, sex, smoking status, residence, hypertension and diabetes. OR: Odds ratio.

Table 4 Associations between variant IRS-2 genotypes and clinicopathological characteristics of gastric cancer

Variable	GD + DD	GG	Crude OR (95% CI)	P value	Adjusted OR1 (95% CI)	P value
Tumor differentiation
Well	15	6	1		1
Moderate	80	35	0.91 (0.33-2.55)	0.864	0.95 (0.33-2.76)	0.921
Poor	29	25	0.46 (0.16-1.38)	0.166	0.38 (0.11-1.35)	0.135
Depth of tumor infiltration
T1	21	14	1		1
T2	20	5	2.67 (0.81-8.77)	0.106	2.70 (0.70-10.47)	0.150
T3	60	26	1.54 (0.68-3.49)	0.302	1.46 (0.60-3.52)	0.401
T4	24	22	0.73 (0.30-1.77)	0.483	0.73 (0.29-1.86)	0.507
Lymph node metastasis
Negative	47	23	1		1
Positive	78	43	0.89 (0.48-1.65)	0.708	0.94 (0.49-1.77)	0.837
Localization
Cardia	27	15	1		1
Non-cardia	101	54	1.04 (0.51-2.12)	0.916	1.08 (0.51-2.29)	0.838

¹Adjusted for age, sex, smoking status, residence, hypertension and diabetes. OR: Odds ratio.