Type 2 diabetes mellitus and colorectal cancer risk in Hispanics: A pilot case-control study

Epidemiological studies have provided inconsistent evidence regarding the potential link between type 2 diabetes mellitus (DM) and colorectal cancer (CRC).This association has not been well characterized in Hispanics, an ethnic minority at high risk for type 2 DM. To evaluate the association between type 2 DM and CRC in Hispanic adults participating in a cohort study of imprinting in CRC. Pilot case-control study included patients with incident CRC and controls with negative colonoscopy and without previous history of CRC or adenomatous polyps, evaluated from January 1, 2005 to June 30, 2007. Diagnosis of type 2 DM was established by previous medical diagnosis and/or anti-diabetic medications use. Unconditional logistic regression was employed to estimate the odds ratio (OR) between type 2 DM and CRC. 42 patients with CRC (mean age 60.4 ±11.1 yrs., 54.8% females), and 51 controls (mean age 55.8 ±10.9 yrs., 72.5% females) were evaluated. Colorectal tumors were mostly adenocarcinomas (95.2%), located in the distal colon (42.9%), and with TNM stage III (28.6%). CRC cases experienced a higher odds of type 2 DM (OR=1.48; 95% CI: 0.49-4.48) compared to controls. Cases with a first degree family history of DM had a three-fold increased odds of CRC (OR=3.11; 95% CI: 1.22-7.97) compared with controls with such a history. Future studies should consider the inclusion of a larger sample size to confirm the excess odds of CRC among Hispanics and understand the contribution of a family history of DM in this association.