Vegetable/fruit, smoking, glutathione S-transferase polymorphisms and risk for colorectal cancer in Taiwan

Table 1 Selected colorectal cancer case and control distribution by sex in Taiwan.

Variable	Men		P1	Women		P1
	Casesn = 410 (%)	Controlsn = 409 (%)		Cases n = 317 (%)	Controlsn = 327 (%)
Age (mean±SD, yr)	60.5±12.2	60.6±12.7		60.2±13.6	60.7±13.4
Colon/rectum, n	185/225			167/150
Physical activity	53 (14.1)	95 (23.2)	<0.01	NI2
Coffee	63 (16.5)	36 ( 8.8)	<0.01	NI2
Smoking			0.18	NA3
Never	122 (31.3)	150 (36.7)
Ex-smoker	91 (23.3)	98 (24.0)
Current	177 (45.4)	161 (39.4)
Alcohol drinking			0.01	NA3
Never	186 (48.1)	205 (50.1)
Ex-drinker	17 (4.4)	37 (9.1)
Current			184 (47.6)	167 (40.8)
High staple4	NI2			156(49.2)	112 (34.3)	<0.01
High meat4	294 (71.7)	244 (59.7)	<0.01	203 (64.0)	151 (46.2)	<0.01
High vegetable/fruit4	168 (44.7)	266 (65.0)	<0.01	147 (50.2)	197 (60.2)	0.01
Fish/shrimp (almost everyday)	174 (46.3)	256 (62.6)	<0.01	125 (42.8)	167 (51.1)	0.04
GSTM1 null	213 (52.2)	215 (52.7)	0.89	189 (60.0)	195 (60.0)	1.00
GSTT1 null	216 (52.9)	189 (46.3)	0.06	180 (57.1)	171 (52.6)	0.25
GSTP1			0.78			0.39
A/A	277 (67.9)	287 (70.2)		224 (71.3)	226 (69.5)
A/G	117 (28.7)	109 (26.7)		84 (26.8)	87 (26.8)
G/G	14 (3.4)	13 (3.2)		6(1.9)	12 (3.7)

¹χ²; ²Not included as covariates in the multiple logistic regression model; ³Not available for analysis; ⁴The cut-point of score using the median of the score distribution among controls for high consumption of staple, meat and vegetable/fruit were <10, <5 and <3 respectively.

Table 2 Odds ratio (OR) and 95% confidence interval (CI) of the polymorphisms of GSTM1, GSTT1 and GSTP1 for colorectal cancer by age at diagnosis and tumor site in men.

	GSTP1		GSTP1		GSTP1
	Present	Null	Present	Null A/A	With	G2
Total population
Cases/Controls	195/193	213/215	192/219	216/189	277/287	131/122
OR (95%CI)1	1.0	0.93 (0.68-1.26)	1.0	1.45 (1.07-1.97)	1.0	1.36 (0.98-1.89)
Tumor site
Colon
Cases/Controls	82/193	101/215	89/219	94/189	127/287	56/122
OR (95%CI)1	1.0	1.00 (0.67-1.48)	1.0	1.24 (0.83-1.83)	1.0 1.15	(0.75-1.76)
Rectum
Cases/Controls	113/193	112/215	103/219	122/189	150/287	75/122
OR (95%CI)1	1.0	0.87 (0.61-1.25)	1.0	1.55 (1.08-2.23)	1.0	1.48 (1.00-2.18)
Age at diagnosis
≤60 yr
Cases/Controls	95/85	92/100	86/106	101/79	124/129	63/56
OR (95%CI)1	1.0	0.86 (0.53-1.30)	1.0	2.03 (1.29-3.21)	1.0	1.45 (0.89-2.37)
>60 yr
Cases/Controls	100/108	121/115	106/113	115/110	153/158	68/66
OR (95%CI)1	1.0	1.03 (0.67-1.58)	1.0	1.12 (0.73-1.71)	1.0	1.34 (0.84-2.12)

¹ORs and 95%CIs were estimated from multivariate unconditional logistic regressions controlling for age, physical activity, coffee, cigarette, alcohol, meat, vegetable/fruit and fish/shrimp;

²Combined genotype of A/G and G/G.

Table 3 Odds ratio (OR) and 95% confidence interval (CI) of the polymorphisms of GSTM1, GSTT1 and GSTP1 for colorectal cancer by age at diagnosis and tumor site in women.

	GSTM1		GSTT1		GSTP1
	Present	Null	Present	Null	A/A	WithG2
Total population
Cases/Controls	126/130	189/195	135/154	180/171	224/226	90/99
OR (95%CI)1	1.0	0.99 (0.71-1.38)	1.0	1.18 (0.85-1.64)	1.0	1.00 (0.70-1.43)
Tumor site
Colon
Cases/Controls	61/130	105/195	72/154	94/171	116/226	49/99
OR (95%CI)1	1.0	1.19 (0.78-1.81)	1.0	1.23 (0.82-1.84)	1.0	1.04 (0.67-1.60)
Rectum
Cases/Controls	65/130	84/195	63/154	86/171	108/226	41/99
OR (95%CI)1	1.0	0.84 (0.56-1.27)	1.0	1.20 (0.79-1.81)	1.0	0.93 (0.60-1.46)
Age at diagnosis
≤60 yr
Cases/Controls	52/52	84/82	50/55	86/79	99/89	37/45
OR (95%CI)1	1.0	1.08 (0.63-1.85)	1.0	1.20 (0.71-2.05)	1	0.84 (0.48-1.47)
>60 yr
Cases/Controls	74/78	105/113	85/99	94/92	125/137	53/54
OR (95%CI)1	1.0	0.95 (0.61-1.46)	1.0	1.15 (0.75-1.76)	1.0	1.13 (0.71-1.80)

¹ORs and 95%CIs were estimated from multivariate unconditional logistic regressions controlling for age, sex, physical activity, coffee, cigarette, alcohol, meat, vegetable/fruit and fish/shrimp;

²Combined genotype of A/G and G/G.

Table 4 Combined genotype of GSTT1 and GSTP1 on colorectal cancer risk by tumor site and age in men.

	GSTT1 / GSTP1
	Present / (A/A)		Present /with G + null / (A/A)		Null /with G
	Cases/Controls	OR (95%CI)1	Cases/Controls	OR (95%CI)1	Cases/Controls	OR (95%CI)1
Total population2	132/157	1.00	205/191	1.42 (1.01-1.99)	71/60	1.91 (1.21-3.02)
Tumor site
Colon	64/157	1	88/191	1.16 (0.75-1.79)	31/60	1.42 (0.79-2.55)
Rectum2	68/157	1.00	117/191	1.65 (1.09-2.50)	40/60	2.20 (1.28-3.78)
Age at diagnosis
≤60 yr2	57/73	1.00	96/89	1.73 (1.04-2.89)	34/23	3.05 (1.51-6.12)
>60 yr	75/84	1.00	109/102	1.25 (0.78-2.02)	37/37	1.41 (0.75-2.64)

¹Adjusted for age, physical activity, coffee, cigarette, alcohol, meat, vegetable/fruit and fish/shrimp;

²Trend test P<0.01.

Table 5 Combined effects of GST genotypes and vegetable/fruit consumption on colorectal cancer risk.

Genotype	Vegetable/fruit consumption	Men			Women
		Cases	Controls	OR (95%CI)1	Cases	Controls	OR (95%CI)2
GSTT1
Null	Low	106	69	1.00	90	62	1
Present	Low	101	74	0.87 (0.55-1.36)	54	66	0.60 (0.36-0.98)
Null	High	110	120	0.57 (0.37-0.88)	90	109	0.47 (0.30-0.75)
Present	High	91	145	0.32 (0.20-0.50)	81	88	0.53 (0.33-0.85)
P for interaction 0.21 0.06
GSTP1
With G	Low	60	49	1.00	44	35	1
A/A	Low	147	94	1.09 (0.67-1.76)	99	93	0.84 (0.49-1.45)
With G	High	71	73	0.73 (0.43-1.25)	46	64	0.51 (0.28-0.94)
A/A	High	130	193	0.40 (0.25-0.64)	125	133	0.58 (0.34-0.99)
P for interaction				0.03			0.42

¹Adjusted for age, physical activity, coffee, cigarette, alcohol, meat, vegetable/fruit and fish/shrimp;

²Adjusted for age, staple, meat, vegetable/fruit and fish/shrimp.

Table 6 Smoking specific risk for colorectal cancer for the combined effects of GST genotypes and vegetable/fruit consumption in men.

Genotype	Vegetable/fruit consumption	Non-smokers			Smokers
		Cases	Controls	OR (95% CI)1	Cases	Controls	OR (95% CI)1
GSTT1
Present	Low	28	16	0.85 (0.33-2.21)	73	58	0.85 (0.51-1.41)
Null	High	45	55	0.41 (0.18-0.96)	59	65	0.66 (0.39-1.11)
Present	High	25	65	0.17 (0.07-0.42)	52	80	0.43 (0.25-0.73)
P for interaction				0.23			0.49
GSTP1
With G	Low	19	10	1.00	41	39	1
A/A	Low	32	19	0.80 (0.30-2.15)	115	75	1.21 (0.69-2.12)
With G	High	25	33	0.41 (0.15-1.10)	40	40	0.96 (0.49-1.88)
A/A	High	45	88	0.21 (0.09-0.52)	71	105	0.55 (0.31-0.98)
P for interaction				0.48			0.07

¹Adjusted for age, physical activity, coffee, alcohol, meat and fish/shrimp.