P373 Meta-analysis: Does folate supplementation reduce colorectal cancer risk in patients with inflammatory bowel disease?
N. Burr*, M. Hull, V. Subramanian
St. James’ University Hospital, Gastroenterology, Leeds, United Kingdom
Colorectal cancer is a serious complication of inflammatory bowel disease (IBD). Folate has been shown to be a potentially chemopreventative agent in sporadic colorectal cancer (CRC). Patients with IBD are at risk of folate deficiency though intestinal malabsorption and also competitive inhibition by concurrent sulfasalazine use. To date there have been several studies reporting folate supplementation in patients with IBD and CRC but no consistent effect has been shown.
We followed a pre-specified and peer-reviewed protocol; the PRISMA statement, a 27 item checklist deemed essential for reporting systematic reviews and meta-analyses of randomized controlled trials and observational studies. We searched electronic databases for studies reporting folate use and CRC incidence in patients with IBD. There were no date or language restrictions. We produced a pooled effect size (ES) with 95% confidence intervals (CI) using a fixed effects model. Heterogeneity amongst studies was calculated using Cochran’s Q statistic and I2. We tested for the effect of different study variables on the overall result using meta-regression and subgroup analyses.
Ten studies, published since 1987, were included in the meta-analysis and reported on a total of 622 cases of IBD associated CRC. We found an overall protective effect of folate supplementation on the development of CRC, pooled ES 0.57 (95% CI, 0.36 - 0.78). Only 3 studies reported matched or adjusted Results. There was low to moderate heterogeneity amongst studies, Cochranes Q= 12.87(p=0.169), I2 30%. Sensitivity analysis suggested that folate use was protective in studies that included dysplasia as an outcome, hospital based studies, high quality studies, studies from North America and those that had matched or adjusted Results.
Chemoprevention remains an attractive option for patients with IBD to prevent dysplasia, reduce the burden of surveillance colonoscopy and also reduce the need for proctocolectomy in patients with ulcerative colitis. The ideal chemopreventative agent would be safe, well tolerated, inexpensive and have a role in suppressing inflammation and malignant transformation 55. Any further reduction to the risk of CRC in IBD is to be welcomed and folate supplementation, as a safe intervention, may be attractive options if further focused population based studies on this topic confirm the findings of this meta-analysis.