Table 3.
Multivariable-adjusted associations of the DIS and LIS with incident, sporadic colorectal adenomas in three pooled case-control studies (CPRU Study, 1991 – 1994; MAP I Study, 1994 – 1997; and MAP II Study, 2002; pooled N = 2,751), overall and according to selected adenoma characteristics
| Inflammation scoresa | ||||
|---|---|---|---|---|
| DISb | LISc | |||
| Adenoma characteristics/inflammation score quintiles | N | Adjusted OR (95% CI) | N | Adjusted OR (95% CI) |
| Any adenoma | ||||
| 1 | 129 | 1.00 (ref) | 102 | 1.00 (ref) |
| 2 | 158 | 1.16 (0.87–1.56) | 118 | 1.13 (0.83–1.55) |
| 3 | 144 | 1.05 (0.78–1.41) | 170 | 1.48 (1.11–1.99) |
| 4 | 157 | 1.16 (0.87–1.56) | 181 | 1.61 (1.20–2.16) |
| 5 | 177 | 1.31 (0.98–1.75) | 194 | 1.98 (1.48–2.66) |
| Ptrend | 0.09 | <0.0001 | ||
| Adenoma location | ||||
| Left colond | ||||
| 1 | 73 | 1.00 (ref) | 61 | 1.00 (ref) |
| 2 | 81 | 1.01 (0.70–1.46) | 71 | 1.17 (0.80–1.72) |
| 3 | 86 | 1.06 (0.74–1.53) | 100 | 1.49 (1.04–2.14) |
| 4 | 95 | 1.19 (0.83–1.71) | 105 | 1.53 (1.07–2.20) |
| 5 | 110 | 1.39 (0.98–1.98) | 108 | 1.79 (1.25–2.57) |
| Ptrend | 0.04 | 0.0004 | ||
| Pheterogeneity | 0.06 | 0.32 | ||
| Right colone | ||||
| 1 | 25 | 1.00 (ref) | 19 | 1.00 (ref) |
| 2 | 48 | 1.96 (1.16–3.40) | 29 | 1.36 (0.74–2.55) |
| 3 | 29 | 1.12 (0.63–2.01) | 30 | 1.29 (0.70–2.40) |
| 4 | 35 | 1.45 (0.83–2.58) | 45 | 2.10 (1.20–3.81) |
| 5 | 45 | 1.72 (1.00–3.00) | 59 | 3.30 (1.92–5.90) |
| Ptrend | 0.22 | <0.0001 | ||
| Pheterogeneity | 0.56 | 0.001 | ||
| Rectum | ||||
| 1 | 27 | 1.00 (ref) | 21 | 1.00 (ref) |
| 2 | 23 | 0.79 (0.44–1.43) | 16 | 0.81 (0.41–1.59) |
| 3 | 26 | 0.94 (0.53–1.67) | 30 | 1.32 (0.74–2.40) |
| 4 | 24 | 0.89 (0.49–1.62) | 29 | 1.34 (0.75–2.45) |
| 5 | 20 | 0.79 (0.42–1.46) | 24 | 1.29 (0.70–2.41) |
| Ptrend | 0.63 | 0.17 | ||
| Pheterogeneity | ref | ref | ||
| Adenoma characteristics | ||||
| < 3 high-risk characteristicsf | ||||
| 1 | 74 | 1.00 (ref) | 59 | 1.00 (ref) |
| 2 | 93 | 1.17 (0.82–1.67) | 58 | 0.93 (0.62–1.40) |
| 3 | 81 | 1.04 (0.72–1.50) | 101 | 1.56 (1.09–2.25) |
| 4 | 79 | 1.03 (0.71–1.49) | 104 | 1.64 (1.14–2.36) |
| 5 | 84 | 1.11 (0.77–1.60) | 89 | 1.59 (1.10–2.32) |
| Ptrend | 0.73 | 0.001 | ||
| Pheterogeneity | ref | ref | ||
| ≥ 3 high-risk characteristicsf | ||||
| 1 | 31 | 1.00 (ref) | 19 | 1.00 (ref) |
| 2 | 31 | 0.92 (0.53–1.59) | 26 | 1.37 (0.74–2.60) |
| 3 | 37 | 1.11 (0.65–1.88) | 35 | 1.58 (0.88–2.90) |
| 4 | 40 | 1.09 (0.64–1.85) | 53 | 2.43 (1.41–4.34) |
| 5 | 53 | 1.51 (0.92–2.52) | 59 | 3.13 (1.83–5.57) |
| Ptrend | 0.09 | <0.0001 | ||
| Pheterogeneity | 0.18 | 0.05 | ||
Abbreviations: CI, confidence interval; CPRU, Cancer Prevention Research Unit; DIS, dietary inflammation score; LIS, lifestyle inflammation score; MAP, Markers of Adenomatous Polyps; MET, metabolic equivalents of task; OR, odds ratio; ref, referent
For construction of inflammation scores, see text and Table 1; higher scores indicate a higher balance of pro- versus anti-inflammatory exposures
Covariates in the DIS unconditional logistic regression models were: age, sex, education (less than college graduate or college graduate or higher), regular aspirin or other nonsteroidal anti-inflammatory drug use (≥ once/week), hormone therapy use (among women), family history of colorectal cancer in a first degree relative (yes/no), smoking status (never, former, or current smoker), body mass index (kg/m2), alcohol intake (non-drinker, moderate drinker, or heavy drinker), physical activity (categorized into tertiles of MET-hours/wk), total energy intake (kcal/day), and study (MAP I, MAP II, or CPRU)
Covariates in the LIS unconditional logistic regression models were: age, sex, regular aspirin or other nonsteroidal anti-inflammatory drug use (≥ once/week), hormone therapy use (among women), family history of colorectal cancer in a first degree relative (yes/no), former smoking status (former smoker or non-former smoker), total energy intake (kcal/day), study (MAP I, MAP II, or CPRU), and the equally-weighted DIS
Right colon: the largest adenoma was located in the cecum, ascending, hepatic flexure, or transverse colon
Left colon: the largest adenoma was located in the splenic flexure, descending, or sigmoid colon
High-risk adenoma characteristics include multiplicity (≥ 2 adenomatous polyps), size ≥ 1 cm, moderate or severe degree of atypia, or having a villous component