Association between the TCF7L2 polymorphism and colorectal cancer does not differ by diabetes and obesity statuses.

This study evaluated the association between polymorphism in a newly identified locus, rs11196172, located in transcription factors 7-like 2 (TCF7L2) and colorectal cancer (CRC) risk according to diabetes and obesity statuses. A study enrolled 6138 CRC patients and 4367 community controls. The adjusted odds ratios (aORs) with age, sex, smoking, and body mass index of the A allele, compared with the G allele, was 1.08 (95% CI 1.01-1.16). The significantly higher risk of CRC with the A allele remained after adjusting for diabetic status (aOR 1.07, 95% CI 1.01-1.15). When stratified by diabetic or obesity status, significant associations between TCF7L2 polymorphism and CRC risk were limited to non-diabetic or normal-weight subjects. No significant interactions between the A/G allele and diabetes status or the A/G allele and overweight status were found. The results indicated that the TCF7L2 rs11196172 polymorphism increases the risk of CRC independently, with no evidence of an interaction with diabetes or obesity.