Korean J Intern Med.  2022 Sep;37(5):969-978. 10.3904/kjim.2021.506.

Factors associated with the risk of colorectal neoplasia in young adults under age 40

• Kim I
• Lee HH
• Ko YJ
• Chang HE
• Cheung DY
• Lee BI
• Cho YS
• Kim JI
• Choi MG

• KMID: 2533140
• DOI: http://doi.org/10.3904/kjim.2021.506

Abstract

Background/Aims
Recent epidemiologic studies have shown a continued increase in colorectal cancer incidence among younger adults. Little is known about the factors that contribute to the development of young-onset colorectal neoplasia (CRN).
Methods
A cross-sectional analysis was performed for individuals younger than 40 years who underwent colonoscopy in Seoul St. Mary’s Hospital and its affiliated health screening center. High-risk CRN was defined as adenoma or sessile serrated lesion ≥ 10 mm, with three or more adenomas, villous histology, high grade dysplasia, or carcinoma.
Results
Of these 13,621 included participants, 2,023 (14.9%) had one and more CRN. Young patients with CRN tended to be elderly, male, obese, smoker, having a habit of drinking, and having comorbidities such as hypertension, dyslipidemia, diabetes, and chronic kidney disease. In a multivariate analysis adjusted for age, sex, obesity, smoking status, and alcohol intake, old age (odds ratio [OR], 1.086; 95% confidence interval [CI], 1.054 to 1.119), male sex (OR, 1.748; 95% CI, 1.247 to 2.451), obesity (OR, 1.439; 95% CI, 1.133 to 1.828), and smoking (OR, 1.654; 95% CI, 1.287 to 2.127) were independent risk factors for overall CRN. Obesity and smoking as two modifiable factors increased the risk for high-risk CRN even more than for overall CRN (OR, 1.734; 95% CI, 1.168 to 2.575 and OR, 1.797; 95% CI, 1.172 to 2.753, respectively).
Conclusions
Obesity and smoking were modifiable risk factors for CRN in young adults. They increased the risk for highrisk CRN even more than for overall CRN. A colonoscopy might be beneficial for young individuals with these factors.

Keyword

Colonoscopy; Colorectal neoplasms; Early detection of cancer; Risk factors