Interleukin-18 gene promoter polymorphisms and the risk of esophageal squamous cell carcinoma

Figures & data

Table I.  Characteristics of the study population.

Variable	ESCC patients (n = 235)	Controls (n = 250)	p
Age (mean±SD)	58.4±9.7	57.6±8.9	0.513
Sex
Male	184 (78.3)	189 (75.6)	0.481
Female	51 (21.7)	61 (24.4)
Cigarette smoking
Non-smokers	59 (25.1)	76 (30.4)	0.194
Smokers	176 (74.9)	174 (69.6)
Alcohol consumption
Non-drinkers	81 (34.5)	101 (40.4)	0.178
Drinkers	154 (65.5)	149 (59.6)
Educational levels
≥ College	32 (13.6)	63 (25.2)	0.001
< College	203 (86.4)	187 (74.8)
Clinical stages
Stages I & II	85 (36.2)
Stages III & IV	150 (63.8)

Table II.  The genotype and allele frequencies of IL-18 promoters of ESCC patients and controls and corresponding OR for ESCC.

Polymorphisms	ESCC patients n = 235 (%)	Controls n = 250 (%)	OR (95% CI)	p
IL-18 -137 G/C
Genotypes
GG	127 (54.0)	176 (70.4)	1.00 (Ref)
GC	91 (38.7)	66 (26.4)	1.91 (1.29–2.82)	0.001
CC	17 (7.2)	8 (3.2)	2.95 (1.23–7.04)	0.012
alleles
G	345 (73.4)	418 (83.6)	1.00 (Ref)
C	125 (26.6)	82 (16.4)	1.85 (1.35–2.53)	<0.001
IL-18 -607 C/A
genotypes
CC	48 (20.4)	59 (23.6)	1.00 (Ref)
CA	123 (52.3)	124 (49.6)	1.22 (0.77–1.92)	0.393
AA	64 (27.2)	67 (26.8)	1.17 (0.70–1.96)	0.539
alleles
C	219 (46.6)	242 (48.4)	1.00 (Ref)
A	251 (53.4)	258 (51.6)	1.08 (0.84–1.38)	0.574

Table III.  Haplotype frequencies of IL-18 promoter of ESCC patients and controls and corresponding OR for ESCC.

IL-18 gene promoter haplotypes	ESCC patients 2n = 470 (%)	Controls 2n = 500 (%)	OR (95% CI)	p
−137 G/ − 607 C	212 (45.1)	244 (48.8)	1.00 (Ref)
−137 G/ − 607 A	131 (27.9)	165 (33.0)	0.91 (0.68–1.23)	0.548
−137 C/ − 607 A	127 (27.0)	91 (18.2)	1.61 (1.16–2.23)	0.004
−137 C/ − 607 C	0 (0.0)	0 (0.0)

Table IV.  The genotype and allele frequencies of IL-18 polymorphism in relation to pathological indices of ESCC severity.

Variable	ESCC patients
Clinical stages	Stages I & II n = 85 (%)	Stages III & IV n = 150 (%)	OR (95% CI)	p
IL-18 −137 G/C
genotypes
GG	48 (56.5)	79 (52.7)	1.00 (Ref)
GC	32 (37.6)	59 (39.3)	1.12 (0.64–1.96)	0.691
CC	5 (5.9)	12 (8.0)	1.46 (0.48–4.40)	0.501
alleles
G	128 (75.3)	217 (72.3)	1.00 (Ref)
C	42 (24.7)	83 (27.7)	1.17 (0.76–1.79)	0.485
IL–18 −607 C/A
genotypes
CC	23 (27.1)	25 (16.7)	1.00 (Ref)
CA	41 (48.2)	82 (54.7)	1.84 (0.93–3.63)	0.077
AA	21 (24.7)	43 (28.7)	1.88 (0.87–4.07)	0.105
alleles
C	87 (51.2)	132 (44.0)	1.00 (Ref)
A	83 (48.8)	168 (56.0)	1.33 (0.92–1.95)	0.134