Table 3.
Multivariable logistic regression analysis to assess the associations of macrophage densities with desmoplastic reaction with IPW.
| Multivariable OR (95% CI) a | |||
|---|---|---|---|
| Immature desmoplastic reaction b | Myxoid stroma | Keloid-like collagen bundles | |
| Overall macrophage density | |||
| Tumor intraepithelial region | |||
| C1 (lowest) | 1 (referent) | 1 (referent) | 1 (referent) |
| C2 (second) | 0.81 (0.52–1.27) | 0.65 (0.44–0.95) | 0.84 (0.57–1.26) |
| C3 (third) | 0.91 (0.57–1.45) | 0.74 (0.50–1.10) | 0.83 (0.55–1.26) |
| C4 (highest) | 0.69 (0.43–1.11) | 0.51 (0.35–0.76) | 0.74 (0.50–1.10) |
| Ptrend c | 0.20 | 0.0030 | 0.15 |
| Tumor stromal region | |||
| C1 (lowest) | 1 (referent) | 1 (referent) | 1 (referent) |
| C2 (second) | 0.73 (0.47–1.14) | 0.83 (0.55–1.24) | 0.98 (0.65–1.47) |
| C3 (third) | 0.71 (0.45–1.11) | 0.69 (0.47–1.03) | 0.99 (0.66–1.48) |
| C4 (highest) | 0.43 (0.27–0.69) | 0.48 (0.32–0.71) | 0.95 (0.64–1.41) |
| Ptrend c | 0.0009 | 0.0002 | 0.82 |
| M1-like macrophage density | |||
| Tumor intraepithelial region | |||
| C1 (lowest) | 1 (referent) | 1 (referent) | 1 (referent) |
| C2 (second) | 0.63 (0.39–1.00) | 0.80 (0.55–1.18) | 0.80 (0.53–1.19) |
| C3 (third) | 0.97 (0.63–1.50) | 0.85 (0.57–1.26) | 0.89 (0.59–1.33) |
| C4 (highest) | 0.64 (0.41–1.01) | 0.64 (0.43–0.94) | 0.66 (0.45–0.98) |
| Ptrend c | 0.21 | 0.042 | 0.076 |
| Tumor stromal region | |||
| C1 (lowest) | 1 (referent) | 1 (referent) | 1 (referent) |
| C2 (second) | 0.66 (0.42–1.04) | 0.73 (0.49–1.08) | 0.83 (0.55–1.25) |
| C3 (third) | 0.71 (0.46–1.11) | 0.71 (0.48–1.05) | 0.97 (0.65–1.44) |
| C4 (highest) | 0.44 (0.28–0.70) | 0.50 (0.34–0.74) | 0.70 (0.47–1.03) |
| Ptrend c | 0.0011 | 0.0007 | 0.14 |
| M2-like macrophage density | |||
| Tumor intraepithelial region | |||
| C1 (lowest) | 1 (referent) | 1 (referent) | 1 (referent) |
| C2 (second) | 0.96 (0.61–1.51) | 1.20 (0.81–1.78) | 1.12 (0.74–1.69) |
| C3 (third) | 0.94 (0.60–1.49) | 0.93 (0.62–1.38) | 1.02 (0.69–1.53) |
| C4 (highest) | 0.83 (0.52–1.33) | 0.82 (0.55–1.24) | 1.00 (0.66–1.52) |
| Ptrend c | 0.45 | 0.21 | 0.88 |
| Tumor stromal region | |||
| C1 (lowest) | 1 (referent) | 1 (referent) | 1 (referent) |
| C2 (second) | 1.09 (0.70–1.71) | 1.05 (0.71–1.57) | 1.20 (0.80–1.82) |
| C3 (third) | 1.01 (0.64–1.60) | 1.14 (0.77–1.68) | 1.60 (1.09–2.37) |
| C4 (highest) | 0.90 (0.57–1.44) | 0.95 (0.65–1.39) | 1.43 (0.96–2.12) |
| Ptrend c | 0.60 | 0.90 | 0.032 |
The multivariable ordinal logistic regression model initially included age, sex, year of diagnosis, family history of colorectal cancer, tumor location, tumor grade, microsatellite instability, CpG island methylator phenotype, long-interspersed nucleotide element-1 methylation level, KRAS, BRAF, and PIK3CA mutations. A backward elimination with a threshold P of 0.05 was used to select variables for the final model.
To avoid violation of the proportional odds assumption, the binary categories were used for desmoplastic reaction (immature vs intermediate/mature).
Ptrend was calculated by the linear trend across the ordinal categories of the macrophage densities (C1–C4, as an ordinal predictor variable) in an ordinal logistic regression model for desmoplastic reaction (three categories), myxoid stroma (four categories), or keloid-like collagen bundles (four categories) (as an ordinal outcome variable).
CI, confidence interval; OR, odds ratio; IPW, inverse probability weighting.