ORs and 95% CIs for colon and rectal cancer, combined and stratified, according to selected risk factors
| Potential confounders | Colorectal cancer | Colon cancer | Rectal cancer | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| OR* | OR (95% CI)† | OR* | OR (95% CI)‡ | OR* | OR (95% CI)§ | |||||||
| Family history of colorectal cancer | ||||||||||||
| No | 1 | 1 | 1 | 1 | 1 | 1 | ||||||
| Yes | 1.83 | 1.89 (1.56-2.30) | 2.02 | 2.15 (1.73-2.68) | 1.38 | 1.46 (1.05-2.05) | ||||||
| BMI (kg/m2)∥ | ||||||||||||
| <22 | 1 | 1 | 1 | 1 | 1 | 1 | ||||||
| ≥28 | 1.31 | 1.28 (1.04-1.56) | 1.37 | 1.28 (1.00-1.64) | 1.12 | 1.04 (0.74-1.46) | ||||||
| Ptrend | 0.03 | 0.07 | 0.7 | |||||||||
| Colorectal cancer screening¶ | ||||||||||||
| No | 1 | 1 | 1 | 1 | 1 | 1 | ||||||
| Yes | 0.75 | 0.78 (0.67-0.90) | 0.78 | 0.76 (0.64-0.91) | 0.70 | 0.72 (0.56-0.92) | ||||||
| Smoking | ||||||||||||
| Never | 1 | 1 | 1 | 1 | 1 | 1 | ||||||
| Ever | 1.18 | 1.20 (1.05-1.38) | 1.12 | 1.14 (0.96-1.34) | 1.39 | 1.39 (1.11-1.75) | ||||||
| Ptrend (pack-years) | 0.04 | 0.05 | 0.4 | |||||||||
| Hormone replacement therapy | ||||||||||||
| Never users | 1 | 1 | 1 | 1 | 1 | 1 | ||||||
| Current users | 0.61 | 0.66 (0.55-0.80) | 0.61 | 0.66 (0.53-0.82) | 0.60 | 0.64 (0.45-0.90) | ||||||
| Recreational physical activity¶ | ||||||||||||
| None | 1 | 1 | 1 | 1 | 1 | 1 | ||||||
| Any | 1.00 | 1.01 (0.87-1.17) | 1.04 | 1.06 (0.89-1.25) | 0.86 | 0.84 (0.66-1.07) | ||||||
| Alcohol consumption | ||||||||||||
| Never | 1 | 1 | 1 | 1 | 1 | 1 | ||||||
| Ever | 0.93 | 0.93 (0.78-1.10) | 0.87 | 0.89 (0.74-1.08) | 1.07 | 1.06 (0.80-1.42) | ||||||
| Education | ||||||||||||
| Less than high school | 1 | 1 | 1 | 1 | 1 | 1 | ||||||
| High school diploma | 0.89 | 0.92 (0.75-1.12) | 0.88 | 1.01 (0.80-1.29) | 0.92 | 0.93 (0.68-1.27) | ||||||
| Some college | 0.92 | 0.98 (0.78-1.25) | 0.94 | 1.11 (0.85-1.47) | 0.85 | 0.88 (0.60-1.28) | ||||||
| College degree or higher | 0.81 | 0.94 (0.71-1.25) | 0.84 | 1.10 (0.79-1.54) | 0.72 | 0.80 (0.52-1.24) | ||||||
↵* Conditional on age and study of enrollment.
↵† Conditional on age and study of enrollment; adjusted for family history of colorectal cancer, BMI, hormone replacement therapy use, and age at first birth.
↵‡ Conditional on age and study of enrollment; adjusted for family history of colorectal cancer, body mass smoking, hormone replacement therapy, alcohol consumption, OC use, age at first birth, and menopausal status.
↵§ Conditional on age and study of enrollment; adjusted for family history of colorectal cancer, physical activity, and hormone replacement therapy.
↵∥ Fourth quartile versus first quartile of BMI in control women.
↵¶ Reference categories are as follows: no history of screening proctoscopic exam (1988-1991) or (1997-2001), did not participate in recreational activity at age 20 (1988-1991) or between ages 14 and 22 (1997-2001).