Disparate age and sex distribution of sessile serrated lesions and conventional adenomas in an outpatient colonoscopy population–implications for colorectal cancer screening?

PURPOSE: Colorectal cancer (CRC) is increasingly diagnosed in individuals aged < 50 years, resulting in advocacy of screening from age 45 years. Despite existing knowledge associating CRC with conventional adenomas, the significance of sessile serrated lesions (SSLs) on the burden of CRC is less detailed. We aimed to provide contemporary estimates for SSL prevalence and examine patient and procedure factors associated with SSL detection. METHODS: Retrospective observational study examining associations between SSL and conventional adenoma detection, polyp histopathology, patient, and procedure characteristics in an outpatient colonoscopy unit over 12 months. RESULTS: From 2097 colonoscopies, SSL detection was 13.8% overall and 12.5% in patients < 50 years. SSLs were mostly proximal in location (64%), and SSL detection was significantly higher in females compared with males (16.2% vs. 11.7%, p = 0.003), particularly in those < 50 years (16.8% vs. 8.6%, p < 0.001). In multivariable analysis, SSL detection was associated with female sex (adjusted odds ratio [aOR] 1.48, 95% confidence interval [CI] 1.15–1.91), synchronous conventional adenoma detection (aOR 1.36, 95% CI 1.04–1.78) and BMI ≥ 25 kg/m(2) (aOR 1.34, 95% CI 1.02–1.77). Conventional adenoma detection was 33.6% and associated with age ≥ 50 years (aOR 3.57, 95% CI 2.84–4.47) and synchronous SSL detection (aOR 1.36, 95% CI 1.03–1.79). CONCLUSIONS: We observed age and sex disparities in polyp types and prevalence in this outpatient colonoscopy population. SSLs were most prevalent in females aged < 50 years, suggesting a potential increased susceptibility of young females to SSLs and CRC. Our findings may have implications for the design of CRC screening programs.