Post-endoscopy colorectal cancer after colectomy in inflammatory bowel disease patients: a population-based register study.

Abstract

Long-standing inflammatory bowel disease (IBD) colitis is an indication for endoscopic surveillance. Postcolonoscopy colorectal cancer (PCCRC), cancer detected after a negative colonoscopy, is a quality indicator for colonoscopy. In analogy with PCCRC, we aimed to assess postendoscopy CRC (PECRC) in individuals with IBD who had undergone colectomy. This register study included Swedish adults with an IBD diagnosis who had undergone colectomy and later were examined by either colonoscopy or sigmoidoscopy during 2001-2012. The final study population had a CRC diagnosis within 36 months of the index examination. Poisson regression was used to assess the relative risks (RR) of PECRC. A total of 33 individuals, 12 with an ileorectal anastomosis and 21 with a rectal remnant, had a CRC diagnosis within 36 months of the index endoscopy. Eleven cancers were detected as CRCs, and 22 (67%) were PECRCs. Compared with individuals aged >70 years, individuals aged <30 years had an RR of 3.1 (P = 0.054) and individuals aged 30-50 years had a RR of 2.6 (P = 0.030). A longer interval between colectomy and index endoscopy (>10 vs. <10 years) was associated with a lower risk of PCCRC (RR = 0.5; P = 0.007). There was no significant difference between the risk for Crohn's disease vs. ulcerative colitis, or between ileorectal anastomosis and rectal remnant risks. Continuous surveillance of IBD patients after colectomy is important. In the postcolectomy context, PECRC may be used as a quality indicator.