Table 2.
Conventional adenoma diagnosed at the first endoscopy and subsequent risk of CRC in the three cohorts (NHS [1990-2012], NHS2 [1989-2013] and HPFS [1990-2012]) a
| No. of participants | No. of CRC cases | Model 1 b | P | Model 2 c | P | Model 3 d | P | |
|---|---|---|---|---|---|---|---|---|
| Non-polyp group | 112,107 | 427 | 1(ref) | 1(ref) | 1(ref) | |||
| Conventional adenomas | 6,161 | 51 | 1.88 (1.40-2.52) | <0.001 | 1.72 (1.28-2.32) | <0.001 | 2.61 (1.93-3.52) | <0.001 |
| Non-advanced conventional adenomas | 3,708 | 12 | 0.86 (0.48-1.53) | 0.6 | 0.80 (0.45-1.43) | 0.46 | 1.21 (0.68-2.16) | 0.52 |
| Advanced conventional adenomas | 2,453 | 39 | 2.96 (2.13-4.13) | <0.001 | 2.67 (1.91-3.73) | <0.001 | 4.07 (2.89-5.72) | <0.001 |
| 1-2 small (<10 mm) tubular adenomas | 3,259 | 10 | 0.86 (0.46-1.61) | 0.64 | 0.81 (0.43-1.52) | 0.51 | 1.23 (0.65-2.31) | 0.52 |
| 1-2 small (<10 mm) adenoma with villous component | 351 | 4 | 2.21 (0.83-5.92) | 0.11 | 1.97 (0.74-5.29) | 0.18 | 2.91 (1.08-7.82) | 0.03 |
| 3-10 tubular adenomas | 369 | 5 | 2.65 (1.09-6.43) | 0.03 | 2.36 (0.97-5.74) | 0.06 | 3.15 (1.29-7.67) | 0.01 |
| one or more tubular adenomas ≥10 mm | 914 | 11 | 2.54 (1.39-4.64) | 0.002 | 2.25 (1.23-4.12) | 0.008 | 3.40 (1.86-6.24) | <0.001 |
| one or more tubulovillous adenomas, any size | 1,145 | 15 | 2.35 (1.40-3.95) | 0.001 | 2.13 (1.27-3.58) | 0.004 | 3.17 (1.88-5.36) | <0.001 |
| one or more villous adenomas, any size | 228 | 10 | 5.88 (3.13-11.1) | <0.001 | 5.16 (2.74-9.72) | <0.001 | 8.51 (4.50-16.1) | <0.001 |
| one or more adenomas with high-grade dysplasia, any size | 166 | 3 | 4.31 (1.38-13.5) | 0.01 | 3.89 (1.24-12.2) | 0.02 | 5.95 (1.88-18.8) | 0.002 |
Abbreviations: CRC, colorectal cancer; NHS, the Nurses’ Health Study; NHS2, the Nurses’ Health Study 2; HPFS, the Health Professionals Follow-up Study.
Advanced conventional adenomas were defined as at least one conventional adenoma of ≥10 mm in diameter or with advanced histology (tubulovillous/villous histological features or high grade or severe dysplasia), otherwise were defined as non-advanced conventional adenomas.
Model 1 was adjusted by age at first endoscopy, study cohort (NHS, NHS2, HPFS), and year of first endoscopy (continuous).
Model 2 was further adjusted for reason for the first endoscopy (routine screening or symptom), family history of colorectal cancer (yes or no), pack-year of smoking (continuous), body mass index (continuous), physical activity (<7.5, 7.5-14.9, 15-29.9, and ≥30 MET-hours/week), alcohol intake (no drinking, <3.5, 3.5-6.9, and ≥7.0 g/day for women; no drinking, <7.0, 7.0-13.9, or ≥14.0 g/day for men), and regular aspirin use (yes or no), based on Model 1.
Model 3 was additionally adjusted for number of surveillance endoscopies (0, 1, 2, >2), based on model 2.