A nationwide database study on colectomy and colorectal cancer in ulcerative colitis: what is the role of appendectomy?

ABSTRACT

AIM: Although has been suggested that an appendectomy has a positive effect on the disease course in patients with ulcerative colitis (UC), recent studies indicate a potential increase in risk of colectomy and colorectal cancer (CRC). This study aimed to evaluate the rates of colectomy and CRC after appendectomy in UC patients using a nationwide prospective database [the Initiative on Crohn and Colitis Parelsnoer Institute - Inflammatory Bowel Disease (ICC PSI-IBD) database]. METHOD: All UC patients were retrieved from the ICC PSI-IBD database between January 2007 and May 2018. Primary outcomes were colectomy and CRC. Outcomes were compared in patients with and without appendectomy, with a separate analysis for timing of appendectomy (before or after UC diagnosis). RESULTS: A total of 826 UC patients (54.7% female; median age 46 years, range 18-89 years) were included. Sixty-three (7.6%) patients had previously undergone appendectomy 24 (38.1%) before and 33 (52.4%) after their diagnosis of UC. In multivariate analysis, appendectomy after UC diagnosis was associated with a significantly lower colectomy rate compared with no appendectomy [hazard ratio (HR) 0.16, 95% C 0.04-0.66, P = 0.011], and the same nonsignificant trend was seen in patients with an appendectomy before UC diagnosis (HR 0.35, 95% CI 0.08-1.41, P = 0.138). Appendectomy was associated with delayed colectomy, particularly when it was performed after diagnosis of UC (P = 0.009). No significant differences were found in the CRC rate between patients with and without appendectomy (1.6% vs 1.2%; P = 0.555). CONCLUSION: Appendectomy in established UC is associated with an 84% decreased risk of colectomy and a delay in surgery. Since the colon is in situ for longer, the risk of developing CRC remains, which underscores the importance of endoscopic surveillance programmes.