Table 3.
Risk of CRC according to GRS and FH of CRC
| Risk factor | Characteristics | Cases, n (%) | Controls, n (%) | OR (95% CI)
|
||
|---|---|---|---|---|---|---|
| Model 1a | Model 2b | Model 3c | ||||
| GRSd | Very low | 134 (5.7) | 220 (10.0) | Ref. | Ref. | Ref. |
| Low | 175 (7.4) | 220 (10.0) | 1.31 (0.98–1.75) | 1.36 (0.99–1.87) | 1.35 (0.98–1.86) | |
| Low–medium | 383 (16.2) | 439 (20.0) | 1.44 (1.11–1.85) | 1.47 (1.12–1.94) | 1.48 (1.12–1.95) | |
| Medium | 431 (18.2) | 439 (20.0) | 1.61 (1.25–2.08) | 1.53 (1.17–2.02) | 1.51 (1.14–1.98) | |
| Medium–high | 548 (23.2) | 441 (20.0) | 2.04 (1.59–2.61) | 2.09 (1.59–2.73) | 2.08 (1.58–2.72) | |
| High | 300 (12.7) | 220 (10.0) | 2.24 (1.70–2.95) | 2.33 (1.72–3.14) | 2.32 (1.71–3.13) | |
| Very high | 392 (16.6) | 219 (10.0) | 2.94 (2.24–3.86) | 3.00 (2.24–4.02) | 2.96 (2.20–3.97) | |
| FH of CRC | No FH | 1833 (77.6) | 1825 (83.0) | Ref. | Ref. | Ref. |
| SDR only | 214 (9.1) | 159 (7.2) | 1.32 (1.07–1.64) | 1.53 (1.21–1.95) | 1.53 (1.21–1.95) | |
| FDR | 316 (13.4) | 214 (9.7) | 1.47 (1.22–1.77) | 1.86 (1.52–2.29) | 1.83 (1.49–2.25) | |
Notes: Values are expressed as n (%).
Adjusted for sex and age.
Adjusted for sex, age (continuous), education (≤9, 10–11, ≥12 years), previous colonoscopy (yes/no), smoking (current/former/never), HRT among women (yes/no), BMI before diagnosis (weight in kilograms divided by squared height in meters); missing values, n = 75.
Adjustment like in model 2, plus additional adjustment for FH in analyses for GRS, and additional adjustment for GRS in analyses for FH, respectively; missing values, n = 75.
GRS with risk alleles as defined in discovery study (Table S1); classification: very low, ≤10th percentile; low, 10th–20th percentile; low–medium, 20th–40th percentile; medium, 40th–60th percentile; medium–high, 60th–80th percentile; high, 80th–90th percentile; very high, >90th percentile.
Abbreviations: BMI, body mass index; CRC, colorectal cancer; FDR, first-degree relative; FH, family history; GRS, genetic risk score; HRT, hormone replacement therapy; OR, odds ratio; Ref., reference; SDR, second-degree relative.