Risk of Cancers in Patients with Pediatric Inflammatory Bowel Diseases: A Systematic Review and Meta-Analysis

Objectives We performed a systematic review and meta-analysis to evaluate the risk of the development of cancers in patients with pediatric-onset inflammatory bowel disease (IBD). Study design A computerized literature search was performed. The primary outcome was the pooled incidence of cancer in studies reporting the risk as a standardized incidence ratio. The secondary outcomes were the pooled incidence rates of all cancers and site-specific cancers including colorectal cancer and hematologic cancers. Results Sixty-six studies reporting outcomes in 38 092 patients were included. The pooled standardized incidence ratio for cancer was 2.39 (P < .0001, 95% CI 2.00-2.86) in IBD. The pooled incidence rates for cancer in patients with Crohn's disease (CD) and ulcerative colitis (UC) were 0.014 (95% CI 0.0087-0.021) and 0.031 (95% CI 0.018-0.052), respectively. The pooled incidence rate of colorectal cancer in CD and UC were 0.0075 (95% CI 0.0049-0.011) and 0.020 (95% CI 0.012-0.034), respectively. The pooled rates of hematologic cancers in CD and UC were 0.0061 (95% CI 0.0040-0.0090) and 0.0045 (95% CI 0.0026-0.0079), respectively. Cumulative metaanalyses showed a decreasing trend in the incidence of these cancers in both CD and UC. Conclusions Patients with pediatric-onset IBD had an increased risk of cancer development compared with the general population, however, incidence appeared to be decreasing in recent years.