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

•Association between TCF7L2 polymorphism and risk of colorectal cancer is confirmed.•Colorectal cancer risk is significantly higher among subjects with A allele compare to with G allele.•The association between TCF7L2 and colorectal cancer risk is independent with diabetes and overweight 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.