Rectal Cancer Risk and Survival After Total Colectomy for IBD: A Population-Based Study

摘要

BACKGROUND: Patients undergoing total colectomy for IBD may develop cancer in the rectal remnant, but the association is poorly understood.OBJECTIVES: This study aimed to examine the risk and prognosis of rectal cancer after total colectomy for IBD.DESIGN: This is a nationwide population-based study.SETTING: Treatment of the patients took place in Denmark from 1977 to 2013.PATIENTS: Patients with IBD undergoing total colectomy were included.MAIN OUTCOME MEASURES: We examined the incidence of rectal cancer among patients with IBD and total colectomy and compared cancer stage to that of other patients with rectal cancer in Denmark. We used Kaplan-Meier methodology to estimate survival and Cox regression to estimate adjusted mortality rate ratios following a rectal cancer diagnosis, comparing patients with and without IBD and a rectal remnant.RESULTS: We identified 4703 patients with IBD (1026 Crohn’s disease; 3677 ulcerative colitis) who underwent total colectomy with a rectal remnant. During 29,725 years of follow-up, 30 rectal cancers were observed, compared with 8 rectal cancers expected (standardized incidence ratio = 3.6 (95% CI, 2.4–5.1)). Cancer stage distributions were similar. Risk of rectal cancer 35 years after total colectomy was 1.9% (95% CI, 1.1%–2.9%). Five years after rectal cancer diagnosis, survival was 28% (95% CI, 12%–47%) and 38% (95% CI, 37%–38%) for patients with and without IBD and a rectal remnant. The adjusted mortality rate ratio 1 to 5 years after a rectal cancer diagnosis was 2.5 (95% CI, 1.6–3.9). Median time from last recorded nondiagnostic proctoscopy to rectal cancer diagnosis for patients with IBD and total colectomy was 1.1 years.LIMITATIONS: This study was limited by the few outcomes and the use of administrative and not clinical data.CONCLUSION: Long-term risk of rectal cancer following total colectomy for IBD was low. Survival following a diagnosis of rectal cancer was poorer for patients with IBD and total colectomy than for patients who had rectal cancer without IBD and total colectomy. Endoscopic surveillance, as it appeared to be practiced in this cohort, may be inadequate. See Video Abstract at http://links.lww.com/DCR/B497.