Table 3.

Relative Risk Estimates for Proximal, Distal, and Rectal Cancers for White Women Age ≥ 50 Years

Variable	Proximal		Distal		Rectal
	OR	95% CI	OR	95% CI	OR	95% CI
Sigmoidoscopy and/or colonoscopy and polyp history
Sigmoidoscopy and/or colonoscopy in last 10 years, and no history of polyps	1.00		1.00		1.00
No sigmoidoscopy and/or colonoscopy in last 10 years	1.82	1.32 to 2.51	3.44	2.31 to 5.11	2.99	1.91 to 4.69
Sigmoidoscopy and/or colonoscopy in last 10 years and history of polyps	2.62	1.52 to 4.50	4.35	2.35 to 8.03	3.19	1.41 to 7.25
Sigmoidoscopy and/or colonoscopy and polyps unknown	0.61	0.17 to 1.04	3.17	1.09 to 4.02	0.37	0.04 to 3.14
No. of relatives with CRC
0	1.00		1.00		1.00
1	1.51	1.11 to 2.03	1.45	1.04 to 2.00	1.53	0.92 to 2.55
≥ 2	2.27	1.25 to 4.14	2.09	1.09 to 4.02
Current vigorous leisure exercise, h/wk
0	1.00				1.00
> 0 and ≤ 2	0.86	0.75 to 1.00			0.69	0.48 to 1.00
> 2 and ≤ 4	0.75	0.56 to 1.00			0.79	0.45 to 1.37
> 4	0.65	0.52 to 0.99			0.63	0.36 to 1.10
Aspirin/NSAID use
Nonuser	1.00		1.00		1.00
Regular user	0.63	0.49 to 0.81	0.70	0.53 to 0.91	0.70	0.50 to 0.97
Vegetable intake, servings/d
< 5	1.00
≥ 5	0.72	0.51 to 1.02
BMI, kg/m2
≤ 29.9			1.00		1.00
≥ 30			1.08	0.75 to 1.54	1.40	0.95 to 2.06
Age, years
≤ 65			1.00
> 65			0.55	0.41 to 0.74
Estrogen status within the last 2 years
Negative	1.00		1.00		1.00
Positive	0.68	0.52 to 0.90	0.48	0.33 to 0.68	0.67	0.48 to 0.94
BMI-estrogen interaction			2.68	1.39 to 5.20

NOTE. Adjusted for study center. Number of cases and controls for covariates used in relative risk estimation can be found in Appendix Table A6, online only.

Abbreviations: OR, odds ratio; CRC, colorectal cancer; NSAID, nonsteroidal anti-inflammatory drug; BMI, body mass index.