Frequency and risk factors of ulcerative colitis associated colorectal cancer referral center experience in non-endemic area

Aims: The incidence of colorectal cancer (CRC) in ulcerative colitis (UC) patients varies across different geographical regions, with limited data available from non-endemic areas for sporadic CRC. This study aimed to evaluate the CRC rates and risk factors in UC patients in a non-endemic region for sporadic CRC. Methods: A retrospective cohort study was conducted on UC patients who had at least 6 months of follow-up between June 1993 and February 2023 at a tertiary referral center in Turkey. Risk factors for CRC development were assessed, including age at UC onset, disease duration, extent of colitis, family history of CRC, and treatment response. Results: A total of 875 UC patients were included in the study. The median age at diagnosis was 38 years, and the median follow up period was 8.16 years. Of these patients, 133 (15.2%) had proctitis, 426 (48.7%) had left-sided colitis, and 316 (36.1%) had extensive colitis. CRC was histologically diagnosed in 5 (0.6%) UC patients, with a median UC onset age of 29.4 years and a total disease duration of 18 years. The median age at CRC diagnosis was 46 years. Three patients had extensive colitis, while two had left-sided colitis. Three patients had steroid dependence, two had thiopurine resistance, and one was biologic treatment resistant. All UC-related CRC patients had persistent mild to moderate disease activity on colonoscopy during follow-up. Conclusion: The low incidence of UC-associated CRC in non-endemic areas may be associated with some environmental and racial factors specific to the region.