MSI status, TGFBR2 and BAX mononucleotide tract mutation and survival of colorectal cancer patients.

The multivariate, stage-matched (stratified) Cox regression model initially included the TGFBR2 mutation or BAX mutation variable, sex, age at diagnosis, year of diagnosis, tumor location, body mass index, family history of colorectal cancer, tumor grade, CIMP, KRAS, BRAF, PIK3CA and LINE-1 methylation. A backward elimination with a threshold of p = 0.20 was used to select variables in the final models. Stage adjustment (I, II, III, IV, unknown) was done using the “strata” option in the SAS “proc phreg” command.CI, confidence interval; HR, hazard ratio; MSI, microsatellite instability; MSS, microsatellite stable.