Background: Patients with inflammatory bowel disease (IBD) are at increased risk of colorectal cancer (CRC), but little is known about the influence of IBD on CRC prognosis.
Aims: The aim of this study was to perform a meta-analysis to compare survival in CRC patients with IBD (IBD-CRC) and without IBD.
Methods: An electronic search was conducted via PubMed, Embase, and the Cochrane Library to identify eligible trials until July 2015. We pooled the hazard ratios (HRs) and their 95% confidence intervals (CIs) to quantitatively assess the survival of CRC in patients with or without IBD. In addition, clinicopathological parameters of IBD-CRC versus non-IBD CRC were evaluated.
Results: Twelve studies containing a total of 3472 IBD-CRC patients were eligible according to our selection criteria. Our analysis indicated that CRC patients with IBD had shorter overall survival than those without IBD (HR 1.24, 95% CI 1.19-1.29). IBD-CRC showed a propensity to develop in proximal colon [odds ratio (OR) 2.52, 95% CI 1.35-4.72] and correlated with worse differentiation of tumor (OR 1.59, 95% CI 1.26-1.99) compared to non-IBD CRC. Meta-regression analysis showed that sample size (P = 0.002) could explain 99.01% inter-study heterogeneity.
Conclusion: This meta-analysis found poorer overall survival in CRC patients with IBD than CRC patients without IBD, and further prospective research to confirm these findings is warranted.
Keywords: Colorectal cancer; Inflammatory bowel disease; Meta-analysis; Survival.