Prevalence and risk of colorectal neoplasms in asymptomatic, average-risk screenees 40 to 49 years of age

Background: A paucity of information exists regarding colorectal neoplasm in asymptomatic, average-risk individuals 40 to 49 years of age. Objective: To evaluate the prevalence and risk factors of colorectal neoplasms in those in their 40s. Design: Cross-sectional study. Setting: Results offered to subjects of a health care provider that offers screening services as part of an employer-provided wellness program. Patients: A consecutive series of 1761 asymptomatic, average-risk screenees 40 to 59 years of age. Intervention: First screening colonoscopy. Results: The prevalence of overall colorectal neoplasm in subjects of ages 40 to 44 years, 45 to 49 years, 50 to 54 years, and 55 to 59 years increased significantly with increasing age (13.7%, 20.2%, 21.0%, and 23.8%, respectively; P < .001). The prevalence of advanced adenomas in subjects of ages 40 to 44 years, 45 to 49 years, 50 to 54 years, and 55 to 59 years increased significantly with age (1.9%, 3.0%, 3.2%, and 5.9%, respectively; P = .004). Multivariate analysis of data from the 40- to 49-year age group identified an increased risk of colorectal neoplasm associated with ages 45 years and older (odds ratio [OR], 1.68; 95% CI, 1.20-2.35), male sex (OR, 1.76; 95% CI, 1.15-2.69), presence of abdominal obesity (OR, 1.57; 95% CI, 1.12-2.21), and metabolic syndrome (OR, 1.56; 95% CI, 1.03-2.35), whereas for advanced adenomas, abdominal obesity (OR, 2.37; 95% CI, 1.06-5.27) and metabolic syndrome (OR, 2.83; 95% CI, 1.23-6.53) were the independent risk factors. Limitations: Single-center study and the cohort composed of ethnic Korean subjects who lived in the same geographic region. Conclusion: In average-risk individuals 40 to 49 years of age, men with abdominal obesity or metabolic syndrome might benefit from screening colonoscopy starting at 45 years of age to detect colorectal neoplasm.