Figure 5. Age-specific incidence of colon cancer per 100,000 person-years according to modifiable risk factors and screening behavior.

Women were enrolled in the Nurses’ Health Study and were followed between 1980 and 2004. Women were assumed to have no postmenopausal hormone use, no aspirin use, average height, no family history of colorectal cancer, and have never been screened for colorectal cancer. 1) a high-risk" participant (one who accrued 10 pack-years of smoking before age 30 years, had a consistently high relative body weight, had physical activity of 2 metabolicMET)-hours/week, consumed 1 serving of red or processed meat per day, was never screened for colon cancer, and had a folate intake of 150 µg/day); 2) a high-risk participant who was screened from age 50 years to age 70 years; 3) a "moderate-risk" participant (one who was a nonsmoker, had an average body mass index, had physical activity of 13.5 MET-hours/week, did not consume red or processed meat, was never screened, and had a folate intake of 300 µg/day); and 4) a “low-risk” participant (one who was a nonsmoker, had a consistently low relative body weight, had physical activity of 21 MET-hours/week, did not consume red or processed meat, was never screened, and had a folate intake of 400 µg/day). Taken from Wei et al.⁴¹⁰