Objectives: To date, there have been no studies on extraintestinal cancer in patients after ileal pouch-anal anastomosis (IPAA) for inflammatory bowel disease (IBD). The aim of this study was to evaluate the frequency and natural history of extraintestinal cancer and their risk factors in patients after IPAA for IBD.
Methods: All patients after IPAA with underlying IBD and extraintestinal neoplasia were identified from a prospectively maintained 932-case Pouchitis Registry from 2002 to 2010. The study group consisted of patients with de novo extraintestinal cancer, which developed after IPAA. Controls were those without extraintestinal cancer, who were randomly selected from the registry with a case to control ratio of 1 to 4. Thirty-one demographic and clinical data were compared between the study and control groups.
Results: Twenty-eight patients with de novo extraintestinal cancer after IPAA were identified, with a mean duration of pouch construction of 8.2 ± 9.7 years. The cumulative frequency of de novo extraintestinal cancer in patients after IPAA for IBD was 3%, consisting of cancer of the breast (18%), kidney (14%), prostate (11%), thyroid (11%), and bladder (7%); melanoma (11%); and other cancers (28%). The mean age of the study group was 57.6 ± 10.1 years, with 16 (57%) being men; 8 (29%) were consuming tobacco, and 3 (11%) having preoperative and/or postoperative biologic use. Patient age, left-sided colitis, and duration of IBD before IPAA were significantly greater in patients in the study group than in controls (P < 0.05) in univariate analysis. Preoperative or postoperative use of biologics and a preoperative diagnosis of colonic neoplasia were not shown to be associated with extraintestinal cancer. The prevalence seemed to be increased in patients with renal cancer with the standardized prevalence ratio of 4.8 (95% confidence interval [CI], 1.6–12.2). In the logistic regression model, older age (odds ratio [OR] = 1.5; 95% CI, 1.2–1.8), left-sided colitis (OR = 12.3; 95% CI, 2.2–67.8), and chronic pouch inflammation (OR = 4.4; 95% CI, 1.5–12.9) were associated with the risk for extraintestinal cancer. The 1-year and 2-year mortality rates after cancer diagnosis were 7.1% and 10.7%, respectively. There was no difference in pouch failure rate between the 2 groups (4% versus 5%; P = 1.00).
Conclusion: The observed number of cases of renal cancer in patients after IPAA appeared to be greater than the expected number of cases in the general population. Older age and chronic pouch inflammation may be associated with an increased risk for extraintestinal cancer in this cohort. Biologic use is not associated with extraintestinal cancer in our population.