Alpha-1-antitrypsin deficiency and smoking as risk factors for mismatch repair deficient colorectal cancer: a study from the colon cancer family registry.

In a previous study, alpha-1-antitrypsin (A1AT) deficiency alleles were found to be over represented among individuals with microsatellite unstable (MSI-high) colorectal cancers, and this was most significant in former or current smokers. We evaluated this association in a larger case-control study, stratified by microsatellite instability phenotypes. Concordant with prior observations, gender (female) and smoking history were positively associated with colorectal cancers having an MSI-high phenotype. No difference in frequency of A1AT deficiency alleles was found between cases and controls, irrespective of the MSI subtype.