Prevalence and risk factors of advanced colorectal neoplasms in asymptomatic Korean people between 40 and 49 years of age

Background and Aim Current guidelines recommend colon cancer screening for persons aged over 50 years. However, there are few data on colorectal cancer screening in 40- to 49-year-olds. This study assessed the prevalence and risk factors of colorectal neoplasms in 40- to 49-year-old Koreans. Methods We analyzed the results of screening colonoscopies of 6680 persons 40–59 years of age (2206 aged 40–49 and 4474 aged 50–59 years). Results The prevalence of overall and advanced neoplasms in the 40- to 49-year age group was lower than in the 50- to 59-year age group (26.7% and 2.4% vs 37.8% and 3.5%, respectively). However, the prevalence of overall and advanced neoplasms increased to 39.1% and 5.4%, respectively, in 45- to 49-year-old individuals with metabolic syndrome. In the 40- to 49-year age group, age, current smoking, and metabolic syndrome were associated with an increased risk of advanced neoplasms (odds ratio [OR] 1.16, 95% confidence interval [CI] 1.04–1.30; OR 3.12, 95% CI 1.20–8.12; and OR 2.00, 95% CI 1.09–3.67, respectively). Conclusions Individuals aged 40–49 years had a lower prevalence of colorectal neoplasms than those aged 50–59 years, but some 40- to 49-year-olds showed a similar prevalence to those aged 50–59 years. Age, current smoking habits, and metabolic syndrome are associated with an increased risk of advanced neoplasms in subjects aged 40–49 years. Further studies are needed to stratify the risks of colon cancer and guide targeted screening in persons younger than 50 years old.