. Author manuscript; available in PMC: 2014 Jan 7.

Published in final edited form as: Int J Cancer. 2011 Aug 8;130(8):10.1002/ijc.26199. doi: 10.1002/ijc.26199

Table 3.

Proband-only analysis of interactions between CYP1A2 -154A>C, NAT2 phenotype and red meat intake

	Colorectal cancer				Colon cancer				Rectal cancer				Heterog. p-value^b
	N	OR^a	95% CI	p-value	N	OR^a	95% CI	p-value	N	OR^a	95% CI	p-value	Heterog. p-value^b
CYP1A2 -154 A>C
*Number of servings of cooked^c red meat per week*
	*≤ 3/>3*				*≤ 3/>3*				*≤ 3/>3*
A/A	168/128	1^ref			97/83	1^ref			52/31	1^ref
A/C	121/96	1.04	0.73-1.48	0.822	48/52	0.78	0.49-1.23	0.285	27/27	1.68	0.84-3.36	0.144
C/C	40/17	0.56	0.30-1.03	0.062	29/8	0.32	0.14-0.74	0.008	7/6	1.44	0.44-4.67	0.546
per C allele		0.85	0.66-1.09	0.206		0.65	0.47-0.90	0.010		1.37	0.83-2.25	0.218	0.014
*Level of doneness of meat in the inside (rare-medium = RM or well-done = WD)*^d
	*RM/WD*				*RM/WD*				*RM/WD*
A/A	176/121	1^ref			102/78	1^ref			56/27	1^ref
A/C	95/123	1.88	1.32-2.68	<0.0001	59/71	1.57	1.0-2.48	0.050	23/32	2.89	1.42-5.84	0.003
C/C	25/32	1.86	1.05-3.29	0.033	16/21	1.72	0.84-3.51	0.138	7/6	1.78	0.54-5.80	0.341
per C allele		1.54	1.19-1.98	0.001		1.39	1.02-1.91	0.039		1.81	1.09-3.01	0.023	0.396
*Level of doneness of red meat from outside (light-medium brown = LMB or heavily browned = HB)*^e
	*LMB/HB*				*LMB/HB*				*LMB/HB*
A/A	208/89	1^ref			119/61	1^ref			67/16	1^ref
A/C	145/73	1.18	0.81-1.71	0.396	89/41	0.90	0.56-1.45	0.664	35/20	2.39	1.10-5.19	0.027
C/C	41/16	0.91	0.49-1.71	0.774	30/7	0.46	0.19-1.10	0.079	6/7	4.88	1.44-16.5	0.011
per C allele		1.03	0.79-1.34	0.819		0.76	0.54-1.08	0.121		2.27	1.32-3.92	0.003	0.0008
NAT2 predicted phenotype
*Number of servings of total red meat per week*
	*≤ 3/>3*				*≤ 3/>3*				*≤ 3/>3*
Slow	222/291	1^ref			141/177	1^ref			54/77	1^ref
Fast	32/20	0.47	0.26-0.85	0.013	15/11	0.58	0.26-1.31	0.193	11/7	0.44	0.16-1.22	0.117	0.683
*Number of servings of cooked^c red meat per week*
	*≤ 3/>3*				*≤ 3/>3*				*≤ 3/>3*
Slow	283/228	1^ref			180/137	1^ref			71/59	1^ref
Fast	40/11	0.34	0.17-0.68	0.002	20/6	0.39	0.15-0.10	0.0519	14/4	0.34	0.1-1.1	0.072	0.858

Obtained from case-only analyses done using unconditional logistic regression models using the dichotomized exposure as the outcome variable and individual SNPs as the independent variables to obtain ORs that would be equivalent to interaction OR (IOR).

colon vs rectum heterogeneity test;

pan-fried, oven-broiled, or grilled;

rare-medium as referent group;

Light or medium browned as referent group.