Ordinal logistic regression analysis to assess independent associations of MSI, CIMP and BRAF mutation status with the amount of Fusobacterium nucleatum DNA in colorectal cancer tissue
| Model for the amount of F. nucleatum DNA (n=953, as an ordinal outcome variable (negative vs low vs high)) | Univariable OR (95% CI) | Multivariable OR (95% CI)* |
|---|---|---|
| MSI-high (vs MSI-low/MSS) | 4.53 (3.04 to 6.75) | 5.22 (2.86 to 9.55) |
| CIMP-high (vs CIMP-low/negative) | 2.51 (1.65 to 3.80) | 0.71 (0.35 to 1.44) |
| BRAF mutant (vs wild type) | 2.23 (1.46 to 3.42) | 1.14 (0.62 to 2.10) |
*In addition to MSI, CIMP and BRAF mutation status, the multivariable ordinal logistic regression analysis model initially included age, sex, year of diagnosis, family history of colorectal carcinoma in parent or sibling, tumour location, KRAS and PIK3CA mutations and LINE-1 methylation level. A backward stepwise elimination with a threshold of p=0.05 was used to select variables in the final models, and the ‘year of diagnosis’ variable remained in the final model.
CIMP, CpG island methylator phenotype; MSI, microsatellite instability; MSS, microsatellite stable.