Table 2

ORs and GREs for risk of colorectal cancer according to individual lifestyle factors

Lifestyle factorPointsDescriptionCRC cases, n (%)Controls, n (%)OR (95% CI)1OR (95% CI)2GRE (95% CI)
Smoking0Smoking: current smoker or former smoker (≥ 30 pack years)1,079 (22.4)704 (17.9)Ref.Ref.Ref.
1Non-smoking: never smoker or former smoker (< 30 pack years)3,735 (77.6)3,237 (82.1)0.75 (0.67, 0.83)0.86 (0.76, 0.97)−12.3 (−22.5, −2.2)
P-interaction with PRS3 = 0.61
Alcohol consumption0Did not meet recommendations on alcoholic drinks41,266 (26.3)911 (23.1)Ref.Ref.Ref.
1Met recommendation on alcoholic drinks43,548 (73.7)3,030 (76.9)0.83 (0.75, 0.92)0.85 (0.76, 0.95)−13.3 (−22.6, −4.0)
P-interaction with PRS3 = 0.45
Diet quality0Unhealthy diet quality: diet quality score < 3453,190 (66.3)2,138 (54.3)Ref.Ref.Ref.
1Healthy diet quality: diet quality score ≥ 3451,624 (33.7)1,803 (45.7)0.59 (0.54, 0.65)0.69 (0.63, 0.76)−30.4 (−39.4, −21.3)
P-interaction with PRS3 = 0.17
Physical activity0Did not meet physical activity guidelines6753 (15.6)486 (12.3)Ref.Ref.Ref.
1Met physical activity guidelines64,061 (84.4)3,455 (87.7)0.75 (0.66, 0.84)0.95 (0.83, 1.09)−4.2 (−15.6, 7.2)
P-interaction with PRS3 = 0.35
BMI0Overweight or obese (BMI ≥ 25 kg/m2)3,384 (70.3)2,447 (62.1)Ref.Ref.Ref.
1Healthy weight (18.5 < BMI < 25 kg/m2)1,430 (29.7)1,494 (37.9)0.67 (0.61, 0.74)0.67 (0.60, 0.74)−32.8 (−42.2, −23.3)
P-interaction with PRS3 = 0.36

1Adjusted for matching factors age and gender. 2Additionally adjusted for school education, family history of CRC, history of colonoscopy, participation in routine health check-ups, use of nonsteroidal anti-inflammatory drugs, PRS (per 10 percentiles, continuous), and mutual adjustment for the other lifestyle factors. 3Interactions were tested by inclusion of a cross-product term of the PRS (continuous variable) and the individual lifestyle factors (categorical variable) along with the main effect terms in multivariable models. 4World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) (2007) Recommendation on alcoholic drinks: ≤ 24 g/day for men and ≤ 12 g/day for women. 5Diet quality score in the highest 40%. 6The WHO Global Recommendations on Physical Activity for Health (2010) recommend that adults engage in at least 150 min of moderate-intensity or 75 min of vigorous-intensity aerobic physical activity throughout the week, or an equivalent combination of moderate and vigorous intensity physical activity (at least ∼500 MET min). BMI, body mass index; CI, confidence intervals; CRC, colorectal cancer; GRE, genetic risk equivalent; OR, odds ratio; PRS, polygenic risk score; Ref., reference.