Retrospective analysis of association of excess body weight with rising incidence of early-onset colorectal cancer in the United States

Incidence of early onset colorectal cancer (EOCRC; diagnosed before age 50 years) has increased substantially since the 1990s in the United States. Researchers at Columbia University (New York, NY) investigated enviromental exposures associated with this increase from 1992 to 2016. The top models consistently identified excess body weight as the strongest risk factor. The best-performing model estimated increased EOCRC incidence due to overweight and obesity, with an incidence rate ratio of 1.20 (95% CI 1.17-1.22) for White men, 1.04 (1.00-1.08) for Black men, 1.17 (1.15-1.21) for White women, and 1.03 (0,97-1.08) for Black women. Increases in overweight and obesity prevalence contributed to an estimated 30% (standard error 1%) for men and 28% (2%) for women of EOCRC incidence during 1992 to 2016. The authors conclude that excess body weight substantially contributed to and is likely a primary driver of the rising incidence of EOCRC in the United States.