[Anthropometry and the risk of colorectal cancer in males: a prospective cohort study]

Objective: To investigate the association between anthropometry and colorectal cancer risk in Chinese males. Methods: Anthropometry and incident colorectal cancer cases were collected on a biennial basis starting in May 2006 among males in Kailuan Cohort (2006-2014). In addition, electronic database of hospitals affiliated to Kailuan Community, Insurance System of Kailuan Community and Tangshan were also searched for supplementary information. Cox proportional hazards regression models and linear models were used to evaluate the association between baseline anthropometry and the risk of colorectal cancer in males. Results: A total of 106 786 males were included and 318 new colorectal cancer cases were identified in the Kailuan male cohort study, with 747 337.60 person-years follow-up by 31 December 2014. The median follow-up time was 7.90 years. Highest quartile waist circumference (≥94.0 cm) or WHtR (≥0.55) had 1.45 (95%CI: 1.05-2.02) and 1.66 (95%CI: 1.15-2.41) higher risk of colorectal cancer when compared with lowest waist circumference (<82.0 cm) or WHtR (<0.48) after adjusting for age, education, smoking, alcohol drinking, sitting time and dust exposure. Subgroup analyses by site indicated that males with BMI ≥26.27 kg/m(2), waist circumference ≥94.0 cm or WHtR ≥0.55 had HRs (95%CI) of 2.18(1.27-3.73), 2.20 (1.27-3.78) and 2.42 (1.29-4.56) for colon cancer risk, respectively. Linear models showed the HR of colon cancer and 95%CI would be 1.59 (1.24-2.02) with every 0.1 growth in WHtR. Conclusion: Obesity may be responsible for an increased risk of colorectal cancer in male. Reasonable weight control may be one of the effective measures to prevent colorectal cancer.