Colon Cancer Surveillance Recommendations After Abnormal Fecal Immunochemical Test and Normal Colonoscopy: Results From the Veterans Administration Population Data

Introduction: The Veterans Health Administration (VA) has achieved high rates of colorectal cancer (CRC) screening through combination of colonoscopy and fecal immunochemical testing (FIT). Patients with abnormal FIT results have a high risk of advanced adenomas or CRC and should complete a follow-up colonoscopy. This study aimed to describe surveillance colonoscopy recommendations in patients with an abnormal FIT result and without adenoma found on colonoscopy. Methods: Using the National VA Healthcare system, we retrospectively identified US Veterans who underwent a colonoscopy with at least one abnormal FIT result within 1-year prior to the colonoscopy. We analyzed pathology data resulted within 30 days of the colonoscopy. Based on this, patients were divided into 3 groups: those without any pathology results, those with non-adenoma histology on pathology, and those with adenomas on pathology. Comparisons of surveillance recommendations between the 3 groups were performed. Results: There were 59,102 patients with an abnormal FIT who underwent colonoscopy during the study period between September 2019 through October 2022. No pathology data was reported in 12,615 (21.3%), non-adenoma histology was reported in 11,707 (19.8%), and adenomatous histology was reported in 34,780 (58.8%) patients. Patients without pathology were older (67 ± 10.76 vs 65 ± 12.03 vs 68 ±9.53 years; P< 0.001) and had fewer males compared to the other groups (81.1% vs 90.2% vs 95.3%; P< 0.001). Surveillance recommendations for all three groups are shown in Figure 1. In patients without pathology, surveillance recommendations for repeat colonoscopy were: 9-10 years in 37.1%, 3-8 years in 29.1%, 0-2 years in 9.7%, and discontinuation of screening in 25.7%. In patients with non-adenoma histology on colonoscopy, surveillance recommendations were: 9-10 years in 30.8%, 3-8 years in 38.1%, 0-2 years in 11.1%, and discontinuation of screening in 19%. Conclusion: About 21% of patients undergoing colonoscopy after a positive FIT did not have any pathology detected on colonoscopic exam. Excluding patients with 1-2 year interval recommendations (possibly attributable to bowel prep or completeness of exam), almost 30% of these patients received recommendations between 3-8 years, possibly earlier than guideline-recommended intervals for normal colonoscopy. Future work will involve determination of patient and provider factors associated with reasons for early interval recommendations in this cohort.Figure 1.: Surveillance Recommendations for Follow-Up Colonoscopy in Patients With Abnormal FIT and Colonoscopy With and Without Pathology.