Background: Screening colonoscopy followed by timely surveillance and rescreening colonoscopy can prevent most colorectal cancers (CRC) by enabling removal of pre-cancerous polyps. Surveillance compliance with professional society guidelines is unknown. We examined compliance patterns of a community-based cohort screened at an endoscopy center in South Carolina with documented 83% and 89% CRC incidence and mortality reductions, respectively, validating very high polyp clearance, which supports using these data to study surveillance timing compliance relative to recommendations. Historically, data sources to study surveillance compliance have been limited because no colonoscopy series is documented with evidence of high polyp clearance at screening. Methods: Patients provided screening colonoscopy from September 4, 2001 to December 31, 2015 followed through July 31, 2016 were studied for surveillance and rescreening colonoscopy timing classified by risk status at screening and to study the impact of the 2006 surveillance guidelines - 1-year surveillance for sessile adenoma removed piecemeal, hyperplastic polyposis syndrome or > 10 adenomas; 3 years for 3-10 adenomas, ≥1cm adenoma, villous features or high-grade dysplasia; 5 years for 1-2 small adenomas; 10 years for no adenoma or < 3 small hyperplastic polyps in left colon). Surveillance was classified as appropriate, overuse and underuse within each risk category. We used Kaplan-Meier analysis with the log-rank test, and logistic regression to identify the factors associated. Findings: Of 14,048 study-eligible patients (after excluding patients aged <40/≥75 years, CRC at screening, 2nd colonoscopy not due during study period, attained 75 years, and missing pathology), majority were female (51.0%), aged 50-59 years (55.1%), black (51.9%), and had Medicare/private insurance (87.9%). Of 6,817 surveillance-eligible, 52.6% completed it, 17% at the appropriate time. Among 3-year- and 5-year-eligibles, overuse (39% and 36%, respectively) and underuse (48.4% and 55.8%, respectively) were widespread. Among the 10-year rescreening-eligible, 45% completed it (mean 5.08 years since screening), 39.9% too early, 5.1% timely or late. Compared to pre-guideline period, overuse decreased among the 5-year category (25.5% vs. 48.6%), and increased among the 3-year category (41.5% vs. 35.4%). Among the 10-year rescreening group, overuse increased (60.4% vs. 31.6%). Overuse more likely among the 5-year group vs. ≤3-year (OR:2.7; 95%CI: 2.1- 3.4). Other overuse predictors were: adenoma ≥1cm (OR:1.9; 95%CI: 1.3-2.7) and multiple advanced adenoma features (OR:2.1; 95%CI: 1.4-3.2). For underuse, right-sided adenoma (OR:1.6; 95%CI: 1.2-2.1) and Medicaid (OR: 3.4; 95%CI: 1.4-8.1) were significant. Conclusions: Surveillance compliance improved following the 2006 guidelines. Underuse by patients with right-sided adenoma and Medicaid insurance needs research and policy attention, as also premature rescreening among low-risk population.

Citation Format: Meng-Han Tsai, Sudha Xirasagar, JiaJia Zhang. Patient compliance with professional society guidelines for surveillance and re-screening following initial screening colonoscopy [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr C131.