Table 4.

Odds ratios (ORs) and 95% confidence intervals (CIs) for colorectal cancer and red meat by cooking method and doneness level

	Quintile of intake^a									P-Trend	P-heterogeneity between subsites^c
	Q1^b	Q2		Q3		Q4		Q5

		OR	95% CI	OR	95% CI	OR	95% CI	OR	95% CI
Grilled/barbequed, g/1,000 kcal
Total colorectal cancer
No. of cases	285		352		352
Age-, sex-, and energy-adjusted	1	0.80	0.64,1.01	0.94	0.74, 1.19					0.702
Multivariable^d	1	0.84	0.66, 1.06	0.94	0.74, 1.20					0.808
Colon cancer^e
No. of cases	205		257		231
Age-, sex-, and energy-adjusted	1	0.82	0.64, 1.06	0.91	0.70, 1.18					0.954
Multivariable	1	0.85	0.66, 1.10	0.91	0.70, 1.19					0.858
Rectal cancer
No. of cases	77		93		119
Age-, sex-, and energy-adjusted	1	0.77	0.54, 1.08	1.03	0.73, 1.44					0.287	0.472
Multivariable	1	0.81	0.57, 1.15	1.05	0.74, 1.48					0.320	0.439
Proximal colon cancer^f
No. of cases	126		162		128
Age-, sex-, and energy-adjusted	1	0.85	0.63, 1.14	0.91	0.66, 1.24					0.866
Multivariable	1	0.89	0.66, 1.20	0.93	0.67, 1.27					0.873
Distal colon cancer
No. of cases	67		93		93
Age-, sex-, and energy-adjusted	1	0.88	0.62, 1.25	0.92	0.64, 1.32					0.888	0.843
Multivariable	1	0.90	0.63, 1.29	0.90	0.63, 1.31					0.750	0.940
Pan-fried, g/1,000 kcal
Total colorectal cancer
No. of cases	178		181		183		188		259
Age-, sex-, and energy-adjusted	1	1.08	0.81, 1.45	1.17	0.87,1.56	1.14	0.85, 1.52	1.64	1.24, 2.18	< 0.001	__
Multivariable	1	0.97	0.71, 1.31	0.99	0.73, 1.34	0.93	0.69, 1.26	1.26	0.93, 1.70	0.044	__
Total colon cancer
No. of cases	133		134		118		130		178
Age-, sex-, and energy-adjusted	1	1.09	0.79, 1.50	1.01	0.73, 1.40	1.06	0.77, 1.46	1.57	1.15, 2.14	0.001	__
Multivariable	1	0.99	0.71, 1.37	0.87	0.62, 1.22	0.88	0.63, 1.23	1.23	0.89, 1.71	0.072	__
Total rectal cancer
No. of cases	45		44		63		58		79
Age-, sex-, and energy-adjusted	1	1.00	0.63, 1.59	1.52	0.98, 2.34	1.33	0.86, 2.06	1.80	1.18, 2.74	0.003	0.640
Multivariable	1	0.87	0.54, 1.39	1.23	0.79, 1.93	1.05	0.66, 1.65	1.31	0.84, 2.04	0.129	0.933
Proximal colon cancer
No. of cases	84		86		71		71		104
Age-, sex-, and energy-adjusted	1	1.15	0.79, 1.67	0.98	0.66, 1.44	0.94	0.64, 1.38	1.55	1.07, 2.23	0.015	__
Multivariable	1	1.05	0.72, 1.55	0.85	0.53, 1.37	0.80	0.54, 1.20	1.25	0.85, 1.83	0.162	__
Distal colon cancer
No. of cases	45		41		45		53		69
Age-, sex-, and energy-adjusted	1	0.94	0.59, 1.49	1.06	0.67, 1.68	1.19	0.76, 1.86	1.58	1.03, 2.43	0.007	0.806
Multivariable	1	0.85	0.53, 1.37	0.91	0.57, 1.46	0.99	0.62, 1.56	1.25	0.85, 1.83	0.104	0.777
Microwaved/baked, g/1,000 kcal ^g
Total colorectal cancer
No. of cases	213		194		196		204		182
Age-, sex-, and energy-adjusted	1	0.93	0.70, 1.23	0.97	0.73, 1.28	1.03	0.78, 1.36	0.90	0.68, 1.20	0.633	__
Multivariable	1	0.89	0.67, 1.20	0.93	0.69, 1.24	0.97	0.72, 1.30	0.87	0.65, 1.17	0.533	__
Total colon cancer
No. of cases	155		132		136		140		130
Age-, sex-, and energy-adjusted	1	0.86	0.63, 1.18	0.93	0.68, 1.27	0.99	0.73, 1.36	0.91	0.66, 1.25	0.852	__
Multivariable	1	0.83	0.60, 1.15	0.99	0.65, 1.22	0.93	0.68, 1.29	0.87	0.63, 1.21	0.709	__
Total rectal cancer
No. of cases	56		61		59		62		51
Age-, sex-, and energy-adjusted	1	1.12	0.74, 1.70	1.09	0.72, 1.66	1.15	0.76, 1.74	0.91	0.59, 1.40	0.524	0.868
Multivariable	1	1.07	0.70, 1.64	1.05	0.68, 1.60	1.08	0.71, 1.65	0.88	0.57, 1.38	0.483	0.968
Proximal colon cancer
No. of cases	86		85		84		92		69
Age-, sex-, and energy-adjusted	1	1.01	0.70, 1.47	1.08	0.74, 1.57	1.25	0.86, 1.80	0.91	0.61, 1.34	0.752	__
Multivariable	1	1.00	0.68, 1.46	1.05	0.72, 1.54	1.21	0.83, 1.76	0.91	0.61, 1.35	0.761	__
Distal colon cancer
No. of cases	62		43		47		46		55
Age-, sex-, and energy-adjusted	1	0.69	0.45, 1.07	0.76	0.49, 1.16	0.75	0.49, 1.16	0.88	0.58, 1.33	0.976	0.894
Multivariable	1	0.65	0.42, 1.01	0.71	0.46, 1.10	0.69	0.45, 1.07	0.82	0.53, 1.25	0.771	0.827
Broiled, g/1,000 kcal
Total colorectal cancer
No. of cases	727		262
Age-, sex-, and energy-adjusted	1	0.97	0.79, 1.19							0.771	__
Multivariable	1	0.99	0.80, 1.22							0.891	__
Total colon cancer
No. of cases	507		186
Age-, sex-, and energy-adjusted	1	0.98	0.78, 1.22							0.834	__
Multivariable	1	0.99	0.79, 1.25							0.951	__
Total rectal cancer
No. of cases	216		73
Age-, sex-, and energy-adjusted	1	0.94	0.70, 1.27							0.687	0.680
Multivariable	1	0.95	0.70, 1.30							0.755	0.670
Proximal colon cancer
No. of cases	297		119
Age-, sex-, and energy-adjusted	1	1.04	0.80, 1.36							0.750	__
Multivariable	1	0.95	0.69, 1.30							0.668	__
Distal colon cancer
No. of cases	189		64
Age-, sex-, and energy-adjusted	1	0.93	0.68, 1.28							0.662	0.327
Multivariable	1	0.95	0.70, 1.29							0.732	0.333
Rare/medium, g/1,000 kcal
Total colorectal cancer
No. of cases	279		362		348
Age-, sex-, and energy-adjusted	1	0.98	0.78, 1.23	1.04	0.82, 1.30					0.658	__
Multivariable	1	0.94	0.75, 1.90	0.99	0.79, 1.26					0.844	__
Total colon cancer
No. of cases	196		257		240
Age-, sex-, and energy-adjusted	1	0.98	0.76, 1.26	1.04	0.81, 1.34					0.649	__
Multivariable	1	0.95	0.73, 1.22	1.00	0.77, 1.30					0.813	__
Total rectal cancer
No. of cases	81		101		107
Age-, sex-, and energy-adjusted	1	0.96	0.69, 1.34	1.04	0.75, 1.45					0.676	0.953
Multivariable	1	0.92	0.66, 1.29	1.00	0.72, 1.40					0.807	0.858
Proximal colon cancer
No. of cases	111		156		149
Age-, sex-, and energy-adjusted	1	1.03	0.77, 1.40	1.22	0.90, 1.66					0.151	__
Multivariable	1	1.00	0.74, 1.36	1.19	0.88, 1.63					0.183	__
Distal colon cancer
No. of cases	79		93		81
Age-, sex-, and energy-adjusted	1	0.92	0.66, 1.29	0.81	0.57, 1.15					0.258	0.026
Multivariable		0.89	0.63, 1.26	0.78	0.54, 1.10					0.179	0.021
Well-done/charred, g/1,000 kcal
Total colorectal cancer
No. of cases	210		176		197		204		202
Age-, sex-, and energy-adjusted	1	0.87	0.66, 1.16	1.04	0.78, 1.38	1.12	0.84, 1.48	1.08	0.81, 1.43	0.287	__
Multivariable	1	0.77	0.57, 1.03	0.92	0.69, 1.24	1.01	0.75, 1.35	0.87	0.64, 1.16	0.857	__
Total colon cancer
No. of cases	156		128		133		139		137
Age-, sex-, and energy-adjusted	1	0.85	0.62, 1.17	0.96	0.70, 1.31	1.06	0.77, 1.44	1.02	0.74, 1.39	0.512	__
Multivariable	1	0.75	0.55, 1.04	0.86	0.63, 1.19	0.96	0.70, 1.32	0.83	0.60, 1.15	0.702	__
Total rectal cancer
No. of cases	53		47		61		65		63
Age-, sex-, and energy-adjusted	1	0.91	0.59, 1.41	1.23	0.81, 1.89	1.31	0.87, 1.99	1.24	0.81, 1.88	0.200	0.394
Multivariable	1	0.79	0.50, 1.23	1.07	0.70, 1.65	1.16	0.76, 1.78	0.96	0.62, 1.48	0.789	0.484
Proximal colon cancer
No. of cases	103		77		76		85		75
Age-, sex-, and energy-adjusted	1	0.76	0.53, 1.11	0.85	0.59, 1.24	1.02	0.71, 1.47	0.89	0.61, 1.29	0.953	__
Multivariable	1	0.68	0.46, 0.99	0.77	0.53, 1.30	0.94	0.65, 1.37	0.73	0.50, 1.08	0.483	__
Distal colon cancer
No. of cases	45		45		55		51		57
Age-, sex-, and energy-adjusted	1	1.02	0.64, 1.61	1.26	0.81, 1.96	1.20	0.76, 1.87	1.29	0.83, 2.00	0.257	0.085
Multivariable	1	0.88	0.55, 1.40	1.12	0.71, 1.76	1.07	0.68, 1.69	1.02	0.65, 1.61	0.815	0.095

Categories of red meat intake were as follows: grilled/barbequed (g/1,000 kcal), tertile 1 (0), tertile 2(0.01-4.35), tertile 3 (> 4.36); pan-fried (g/1,000 kcal), quintile 1 (< 0.36), quintile 2 (0.36-1.39), quintile 3 (1.40-3.33), quintile 4 (3.34-6.79), quintile 5 (> 6.79); microwaved/baked (g/1,000 kcal), quintile 1 (< 4.65), quintile 2 (4.65-7.56), quintile 3 (7.67-11.4), quintile 4 (11.5-18.6), quintile 5 (> 18.6); broiled (any versus no consumption); rare/medium (g/1000 kcal), tertile 1 (0), tertile 2 (0.01-4.08), tertile 3 (> 4.08); well-done/charred (g/1000 kcal), quintile 1 (< 0.89), quintile 2 (0.89-2.41), quintile 3 (2.42-4.70), quintile 4 (4.71-8.96), quintile 5 (> 8.96).

Referent quintile.

Effect heterogeneity was evaluated between colon and rectal cancer and proximal and distal colon cancer.

ORs were adjusted for age, sex, total energy intake, body mass index, past regular NSAID use, and fruit and vegetable consumption. Red meat and poultry were mutually adjusted for each other.

7 cases lacked anatomical subsite information.

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

Microwaved/baked and rare/medium red meat were categorized into tertiles, with zero consumption as the referent group, due to smaller intake ranges and and more than 20 percent zero values. Broiled red meat was a dichotomous variable (any or no consumption) due to more than 50 percent zero values.