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.