Table 3.
Associations between antibiotic use and colorectal cancer.
| Primary analyses | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| <50 years | ≥50 years | |||||||||
| Site | Medicine | Cases n (%) | Controls n (%) | Adjustedb OR (95% CI) | Adjustedb p-value | Cases n (%) | Controls n (%) | Adjustedb OR (95% CI) | Adjustedb p-value | Interaction test p-value |
| Colon | Any antibiotic use | 141 (48.8%) | 492 (40.4%) | 1.49 (1.07, 2.07) | 0.018 | 2422 (48.5%) | 8775 (46.0%) | 1.09 (1.01, 1.18) | 0.029 | 0.071 |
| Anti-anaerobic activitya | 107 (37.0%) | 386 (31.7%) | 1.34 (0.97, 1.86) | 0.078 | 1827 (36.6%) | 6594 (34.6%) | 1.08 (1.00, 1.17) | 0.054 | 0.204 | |
| Non-anti-anaerobic activitya | 91 (31.5%) | 303 (24.9%) | 1.37 (0.97, 1.93) | 0.075 | 1585 (31.8%) | 5741 (30.1%) | 1.03 (0.95, 1.11) | 0.500 | 0.151 | |
| Rectum | Any antibiotic use | 69 (44.2%) | 69 (44.2%) | 1.17 (0.75, 1.84) | 0.493 | 1074 (43.6%) | 3968 (42.0%) | 1.07 (0.96, 1.19) | 0.238 | 0.698 |
| Anti-anaerobic activitya | 56 (35.9%) | 56 (35.9%) | 1.11 (0.70, 1.76) | 0.646 | 803 (32.6%) | 3026 (32.0%) | 1.00 (0.89,1.11) | 0.974 | 0.650 | |
| Non-anti-anaerobic activitya | 44 (28.2%) | 44 (28.2%) | 1.70 (1.06, 2.74) | 0.029 | 684 (27.7%) | 2499 (26.4%) | 1.05 (0.93, 1.18) | 0.436 | 0.888 | |
| Subgroup analyses | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Proximal colon | Any antibiotic use | 31 (62.0%) | 87 (41.0%) | 3.78 (1.60, 8.92) | 0.002 | 272 (42.7%) | 1048 (43.3%) | 0.92 (0.74, 1.13) | 0.315 | 0.001 |
| Anti-anaerobic activitya | 22 (44.0%) | 64 (30.2%) | 2.17 (1.00, 4.68) | 0.049 | 208 (32.7%) | 744 (30.8%) | 1.10 (0.88, 1.37) | 0.537 | 0.034 | |
| Non-anti-anaerobic activitya | 19 (38.0%) | 53 (25.0%) | 2.86 (1.21, 6.73) | 0.016 | 179 (28.1%) | 741 (30.7%) | 0.79 (0.64, 0.99) | 0.036 | 0.153 | |
| Distal colon | Any antibiotic use | 20 (55.6%) | 60 (40.0%) | 3.39 (1.02, 11.28) | 0.047 | 245 (47.6%) | 896 (44.2%) | 1.14 (0.90, 1.44) | 0.289 | 0.083 |
| Anti-anaerobic activitya | 12 (33.3%) | 51 (34.0%) | 1.06 (0.35, 3.23) | 0.922 | 178 (34.6%) | 675 (33.3%) | 1.02 (0.80, 1.31) | 0.971 | 0.930 | |
| Non-anti-anaerobic activitya | 16 (44.4%) | 31 (20.7%) | 5.17 (1.71, 15.60) | 0.004 | 152 (29.5%) | 578 (28.5%) | 1.01 (0.79, 1.29) | 0.990 | 0.916 | |
OR odds ratio, CI confidence interval.
aPrimary clinical therapeutic effect on gut microbe.
bAdjusted for diabetes, myocardial infarction, coronary heart disease, heart failure, peripheral vascular disease, dementia, cerebrovascular disease, chronic obstructive pulmonary disease, osteoporosis, renal disease, liver disease, hemiplegia/paraplegia, gallstones, acromegaly, low dose aspirin and NSAIDs.