Interaction models of CYP1A1, GSTM1 polymorphisms and tobacco smoking in intestinal gastric cancer

Table 1 Characteristics of the interviewed subjects

	Characteristics	Gastric cancer cases (114)	Control subjects (693)	OR (95%CI)
Median age	yr±SD	59±10	53±10	1.1 (1.0–1.1)1
	Min (yr)	35	30
	Max (yr)	82	78
Gender	Female (%)	38 (33)	383 (55)	1.0 (Ref.)
	Male (%)	76 (67)	310 (45)	1.2 (0.7–2.1)
	F/M ratio	1:2	01:00.8
Educational level	>5 yr	44 (38.6)	246 (35.5)	1.0 (Ref.)
	≤5 yr	70 (61.4)	447 (64.5)	1.0 (0.6–1.7)
Occupation
	Manual	51 (44.7)	375 (54.1)	1.0 (Ref.)
	Office	9 (7.9)	87 (12.6)	0.6 (0.2–1.3)
	Retired	54 (47.4)	231 (33.3)	1.2 (0.7–1.9)
Marriage status
	Married	100 (87.7)	649 (94.7)	1.0 (Ref.)
	Divorce or bereft spouse	14 (12.3)	36 (5.3)	1.4 (0.6–3.0)
Family history of cancer
	No	84 (76.4)	613 (90.3)	1.0 (Ref.)
	Yes	26 (23.6)	66 (9.7)	3.9 (2.1–7.3)1
BMI (kg/m2)
	<20	56 (49.1)	95 (13.7)	1.0 (Ref.)
	20–	44 (38.6)	254 (36.7)	0.3 (0.2–0.5)1
	23–	14 (12.3)	344 (49.6)	0.1 (0.03–0.12)1
Tobacco smoking habits
	Never	51 (44.7)	437 (63.0)	1.0 (Ref.)
	Current	36 (31.6)	225 (32.5)	0.6 (0.3–1.3)
	Former	27 (23.7)	31 (4.5)	2.4 (1.0–5.8)1
Amount of former smoking (pack years)
	No	87 (76.4)	662 (95.6)	1.0 (Ref.)
	1–19	7 (6.1)	10 (1.4)	2.6 (0.8–8.6)
	20–29	8 (7.0)	11 (1.6)	3.1 (1.1–9.0)1
	≥30	12 (10.5)	10 (1.4)	4.4 (1.7–11.9)1
Alcohol drinking habits
	Never	78 (68.5)	505 (72.9)	1.0 (Ref.)
	Current	11 (9.6)	156 (22.5)	0.2 (0.1–0.5)1
	Former	25 (21.9)	32 (4.6)	2.3 (1.2–4.7)1
Plasma H pylori CagA antibody
	Negative	136 (82.4)	107 (49.3)	1.0 (Ref.)
	Positive	29 (17.6)	110 (50.7)	0.2 (0.1–0.3)1
CYP1A1 genotype
	Ile/Ile	70 (62.5)	412 (61.0)	1.0 (Ref.)
	Ile/Val	36 (32.1)	226 (33.4)	0.9 (0.5–1.4)
	Val/Val	6 (5.4)	38 (5.6)	0.7 (0.2–1.8)
GSTM1 genotype
	Present	41 (36.6)	314 (46.5)	1.0 (Ref.)
	Null	71 (63.4)	361 (53.5)	2.0 (1.2–3.1)1

¹Showed significant difference after adjusting co-variables.