Table 3.

Odds ratios and 95% confidence intervals (CIs) of colorectal cancer, by quintile of meat-related compounds

	Quintile of intakea									P-trend	P-heterogeneity between subsitesc
	Q1b	Q2		Q3		Q4		Q5
		OR	95% CI	OR	95% CI	OR	95% CI	OR	95% CI
Nitrites plus nitrates (μg/1,000 kcal)
Total colorectal cancer
No. of cases	182		177		194		211		225
Age-, sex-, and energy-adjusted	1	1.06	0.79, 1.41	1.19	0.89, 1.59	1.23	0.92, 1.65	1.44	1.07, 1.93	0.008	__
Multivariabled	1	0.98	0.72, 1.32	1.07	0.79, 1.45	1.09	0.80, 1.47	1.19	0.87, 1.61	0.189	__
Total colon cancere
No. of cases	126		124		140		146		157
Age-, sex-, and energy-adjusted	1	1.09	0.79, 1.51	1.27	0.92, 1.75	1.28	0.93, 1.77	1.53	1.11, 2.12	0.008	__
Multivariable	1	1.02	0.73, 1.42	1.15	0.83, 1.61	1.14	0.82, 1.60	1.28	0.92, 1.80	0.115	__
Rectal cancer
No. of cases	53		52		54		63		67
Age-, sex-, and energy-adjusted	1	1.04	0.68, 1.60	1.10	0.71, 1.69	1.17	0.77, 1.79	1.32	0.86, 2.02	0.152	0.482
Multivariable	1	0.95	0.61, 1.48	0.96	0.62, 1.50	1.02	0.66, 1.58	1.04	0.67, 1.62	0.722	0.363
Proximal colon cancerf
No. of cases	77		75		86		76		102
Age-, sex-, and energy-adjusted	1	1.11	0.75, 1.64	1.35	0.92, 1.98	1.16	0.78, 1.72	1.81	1.24, 2.66	0.002	__
Multivariable	1	1.05	0.71, 1.56	1.25	0.85, 1.86	1.06	0.71,1.58	1.57	1.06, 2.34	0.023	__
Distal colon cancer
No. of cases	43		45		50		64		51
Age-, sex-, and energy-adjusted	1	1.08	0.68, 1.72	1.19	0.76, 1.89	1.46	0.94, 2.27	1.21	0.76, 1.92	0.339	0.101
Multivariable	1	0.99	0.62, 1.59	1.06	0.67, 1.70	1.28	0.81, 2.01	0.98	0.61, 1.58	0.952	0.076
DiMeIQx (ng/1,000 kcal)
Total colorectal cancer
No. of cases	181		185		203		183		237	181
Age-, sex-, and energy-adjusted	1	1.06	0.79, 1.42	1.15	0.86, 1.54	1.12	0.83, 1.48	1.48	1.12, 1.96	0.004	__
Multivariable	1	1.04	0.77, 1.40	1.09	0.81, 1.47	1.03	0.77, 1.39	1.36	1.02, 1.82	0.027	__
Total colon cancer
No. of cases	127		132		152		127		155
Age-, sex-, and energy-adjusted	1	1.09	0.79, 1.51	1.25	0.91, 1.72	1.12	0.81, 1.55	1.43	1.04, 1.96	0.034	__
Multivariable	1	1.07	0.77, 1.49	1.19	0.86, 1.64	1.05	0.75, 1.46	1.32	0.95, 1.82	0.118	__
Rectal cancer
No. of cases	51		52		49		56		81
Age-, sex-, and energy-adjusted	1	1.04	0.67, 1.61	0.98	0.63,1.52	1.16	0.76, 1.79	1.67	1.11, 2.51	0.003	0.591
Multivariable	1	1.01	0.65, 1.57	0.92	0.59, 1.44	1.08	0.70, 1.67	1.54	1.02, 2.33	0.010	0.637
Proximal colon cancer
No. of cases	79		78		101		78		80
Age-, sex-, and energy-adjusted	1	1.03	0.70, 1.52	1.35	0.93, 1.95	1.14	0.77, 1.67	1.30	0.84, 1.80	0.356	__
Multivariable	1	1.01	0.68, 1.49	1.28	0.88, 1.87	1.08	0.73, 1.59	1.14	0.77, 1.69	0.598	__
Distal colon cancer
No. of cases	40		50		45		48		70
Age-, sex-, and energy-adjusted	1	1.26	0.80, 2.00	1.13	0.71, 1.81	1.24	0.78, 1.97	1.82	1.18, 2.82	0.005	0.242
Multivariable	1	1.22	0.77, 1.94	1.07	0.66, 1.71	1.15	0.72, 1.84	1.66	1.06, 2.59	0.020	0.266
MeIQx (ng/1,000 kcal)
Total colorectal cancer
No. of cases	194		170		185		197		243
Age-, sex-, and energy-adjusted	1	0.94	0.71, 1.26	1.03	0.77, 1.38	1.13	0.85, 1.51	1.40	1.06, 1.86	0.003	__
Multivariable	1	0.90	0.67, 1.22	0.96	0.71, 1.29	1.05	0.78, 1.41	1.22	0.91, 1.64	0.047	__
Total colon cancer
No. of cases	142		115		139		126		171
Age-, sex-, and energy-adjusted	1	0.89	0.64, 1.23	1.10	0.80, 1.50	1.02	0.74, 1.40	1.40	1.03, 1.91	0.007	__
Multivariable	1	0.85	0.61, 1.19	1.02	0.74, 1.41	0.95	0.68, 1.32	1.23	0.89, 1.69	0.068	__
Rectal cancer
No. of cases	50		55		44		70		70
Age-, sex-, and energy-adjusted	1	1.15	0.75, 1.77	0.90	0.57, 1.42	1.47	0.97, 2.22	1.47	0.97, 2.22	0.029	0.969
Multivariable	1	1.09	0.70, 1.69	0.82	0.52, 1.30	1.34	0.87, 2.05	1.24	0.81, 1.91	0.172	0.906
Proximal colon cancer
No. of cases	87		74		96		69		90
Age-, sex-, and energy-adjusted	1	0.96	0.65, 1.40	1.29	0.89, 1.87	0.95	0.64, 1.40	1.25	0.87, 1.82	0.249	__
Multivariable	1	0.92	0.62, 1.36	1.21	0.83, 1.76	0.89	0.60, 1.32	1.11	0.76, 1.63	0.591	__
Distal colon cancer
No. of cases	45		38		40		54		76
Age-, sex-, and energy-adjusted	1	0.87	0.54, 1.40	0.92	0.58, 1.47	1.22	0.78, 1.91	1.74	2.14, 2.65	<0.001	0.332
Multivariable	1	0.83	0.51, 1.34	0.84	0.52, 1.35	1.13	0.72, 1.77	1.49	0.97, 2.30	0.005	0.373
PhIP (ng/1,000 kcal)
Total colorectal cancer
No. of cases	223		207		186		190		183
Age-, sex-, and energy-adjusted	1	1.03	0.78, 1.36	0.95	0.72, 1.26	1.05	0.79, 1.39	1.15	0.86, 1.54	0.266	__
Multivariable	1	0.97	0.73, 1.29	0.87	0.65, 1.16	0.98	0.73, 1.31	1.06	0.79, 1.43	0.439	__
Total colon cancer
No. of cases	163		154		135		131		110
Age-, sex-, and energy-adjusted	1	1.07	0.79, 1.45	0.98	0.72, 1.34	1.05	0.77, 1.44	1.02	0.74, 1.42	0.944	__
Multivariable	1	1.01	0.74, 1.38	0.90	0.66, 1.24	0.98	0.71, 1.35	0.95	0.68, 1.33	0.830	__
Rectal cancer
No. of cases	59		49		51		57		73
Age-, sex-, and energy-adjusted	1	0.87	0.58, 1.36	0.91	0.59, 1.39	1.05	0.69, 1.59	1.44	0.96, 2.17	0.013	0.149
Multivariable	1	0.82	0.53, 1.26	0.81	0.53, 1.26	0.97	0.63,1.49	1.33	0.88, 2.02	0.023	0.167
Proximal colon cancer
No. of cases	99		102		78		87		50
Age-, sex-, and energy-adjusted	1	1.20	0.84, 1.71	0.99	0.68, 1.43	1.28	0.89, 1.85	0.87	0.57, 1.31	0.425	__
Multivariable	1	1.15	0.80, 1.64	0.92	0.63, 1.35	1.21	0.83, 1.76	0.81	0.54, 1.24	0.313	__
Distal colon cancer
No. of cases	55		48		51		42		57
Age-, sex-, and energy-adjusted	1	0.92	0.60, 1.43	0.97	0.63, 1.49	0.83	0.53, 1.31	1.21	0.79, 1.87	0.251	0.328
Multivariable	1	0.86	0.55, 1.34	0.88	0.57, 1.36	0.76	0.48, 1.21	1.11	0.72, 1.72	0.363	0.356
benzo[a]pyrene (ng/1,000 kcal)
Total colorectal cancer
No. of cases	264		219		152		184		170
Age-, sex-, and energy-adjusted	1	0.94	0.72, 1.23	0.71	0.53, 0.95	0.92	0.69, 1.22	0.91	0.68, 1.21	0.926	__
Multivariable	1	0.95	0.72, 1.25	0.69	0.52, 0.93	0.92	0.69, 1.23	0.90	0.67, 1.21	0.906	__
Total colon cancer
No. of cases	199		153		108		133		100
Age-, sex-, and energy-adjusted	1	0.90	0.67, 1.21	0.69	0.51, 0.95	0.94	0.69, 1.27	0.78	0.56, 1.08	0.347	__
Multivariable	1	0.91	0.67, 1.23	0.67	0.49, 0.93	0.93	0.68, 1.27	0.77	0.55, 1.07	0.325	__
Rectal cancer
No. of cases	63		64		43		50		69
Age-, sex-, and energy-adjusted	1	1.07	0.71, 1.60	0.78	0.50, 1.21	0.92	0.60, 1.40	1.25	0.83, 1.89	0.143	0.031
Multivariable	1	1.09	0.72, 1.64	0.77	0.49, 1.20	0.92	0.60, 1.43	1.26	0.83, 1.91	0.145	0.027
Proximal colon cancer
No. of cases	131		102		62		68		53
Age-, sex-, and energy-adjusted	1	0.95	0.68, 1.33	0.63	0.43, 0.91	0.79	0.55, 1.14	0.72	0.48, 1.07	0.171	__
Multivariable	1	0.95	0.68, 1.34	0.61	0.42, 0.90	0.79	0.55, 1.15	0.71	0.48, 1.06	0.159	__
Distal colon cancer
No. of cases	57		47		44		61		44
Age-, sex-, and energy-adjusted	1	0.88	0.57, 1.37	0.87	0.56, 1.36	1.23	0.81, 1.86	0.90	0.57, 1.42	0.967	0.448
Multivariable	1	0.88	0.57, 1.37	0.84	0.54, 1.32	1.22	0.80, 1.87	0.89	0.56, 1.41	0.949	0.436
Total mutagenic activity (revertant colonies/1,000 kcal)
Total colorectal cancer
No. of cases	208		192		187		208		194
Age-, sex-, and energy-adjusted	1	0.95	0.72, 1.27	1.00	0.75, 1.33	1.16	0.87, 1.54	1.16	0.87, 1.54	0.139	__
Multivariable	1	0.91	0.68, 1.21	0.93	0.70, 1.25	1.06	0.79, 1.41	1.05	0.78, 1.41	0.433	__
Total colon cancer
No. of cases	154		135		135		141		128
Age-, sex-, and energy-adjusted	1	0.92	0.67, 1.25	1.00	0.73, 1.37	1.10	0.81, 1.51	1.10	0.80, 1.51	0.325	__
Multivariable	1	0.87	0.64, 1.20	0.95	0.69, 1.30	1.01	0.74, 1.39	0.99	0.72, 1.37	0.707	__
Rectal cancer
No. of cases	52		55		52		65		65
Age-, sex-, and energy-adjusted	1	1.07	0.70, 1.65	1.04	0.68, 1.61	1.34	0.88, 2.03	1.37	0.90, 2.09	0.078	0.361
Multivariable	1	1.01	0.65, 1.56	0.96	0.62, 1.50	1.22	0.79, 1.86	1.23	0.80, 1.89	0.210	0.410
Proximal colon cancer
No. of cases	98		89		82		84		63
Age-, sex-, and energy-adjusted	1	0.94	0.65, 1.35	0.99	0.69, 1.43	1.08	0.74, 1.56	0.91	0.62, 1.34	0.794	__
Multivariable	1	0.91	0.63, 1.31	0.94	0.65, 1.37	1.00	0.69, 1.45	0.83	0.56, 1.24	0.493	__
Distal colon cancer
No. of cases	46		42		49		53		63
Age-, sex-, and energy-adjusted	1	0.92	0.58, 1.46	1.10	0.70, 1.73	1.22	0.78, 1.91	0.91	0.61, 1.34	0.020	0.095
Multivariable	1	0.88	0.55, 1.40	1.03	0.65, 1.62	1.11	0.71, 1.74	1.34	0.86, 2.08	0.068	0.107

Abbreviations: DiMeIQx, 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline; MeIQx, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline; PhIP, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine.

^aQuintiles of intake were as follows: nitrites plus nitrates (μg/1,000 kcal), quintile 1 (< 114.6), quintile 2 (114.6-197.0), quintile 3 (197.1-310.2), quintile 4 (310.3-496.6), quintile 5 (> 496.6); DiMeIQx (ng/1,000 kcal), quintile 1 (< 0.23), quintile 2 (0.23-0.67), quintile 3 (0.68-1.23), quintile 4 (1.24-2.20), quintile 5 (> 2.20); MeIQx (ng/1,000 kcal), quintile 1 (< 4.2), quintile 2 (4.2-8.3), quintile 3 (8.4-14.2), quintile 4 (14.3-23.8), quintile 5 (> 23.8); PhIP (ng/1,000 kcal), quintile 1 (< 7.2), quintile 2 (7.2-17.4), quintile 3 (17.5-33.7), quintile 4 (33.8-68.3), quintile 5 (> 68.3); benzo[a]pyrene (ng/1,000 kcal), quintile 1 (< 0.32), quintile 2 (0.32-2.2), quintile 3 (2.3-6.6), quintile 4 (6.7-19.0), quintile 5 (> 19.0); total mutagenic activity (revertant colonies/1,000 kcal), quintile 1 (< 665), quintile 2 (665-1,344), quintile 3 (1,345-2,310), quintile 4 (2,311-3,995), quintile 5 (> 3,995).

^bReferent quintile.

^cEffect heterogeneity was evaluated between colon and rectal cancer and proximal and distal colon cancer.

^dORs were adjusted for age, sex, total energy intake, body mass index, past regular NSAID use, and fruit and vegetable consumption.

^e7 cases lacked anatomic subsite information.

^f24 cases had colon cancer in overlapping sites or not otherwise specified colon sites.