Prognostic Factors for Advanced Colorectal Neoplasia in Inflammatory Bowel Disease: Systematic Review and Meta-analysis

Gastroenterology. 2021 Apr;160(5):1584-1598. doi: 10.1053/j.gastro.2020.12.036. Epub 2020 Dec 29.

Abstract

Background and aims: Patients with inflammatory bowel disease (IBD) have an increased risk of colorectal cancer (CRC). We performed a systematic review and meta-analysis to identify all prognostic factors for advanced colorectal neoplasia (aCRN, high-grade dysplasia, or CRC) in patients with IBD.

Methods: A systematic literature search was conducted according to the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines. Risk of bias was assessed using the Quality in Prognostic Studies tool. Random-effects models were created separately for odds and hazard ratios, different study designs, and univariable or multivariable data. The evidence for all prognostic factors was categorized as "weak", "moderate", or "strong", based on estimate of effect sizes, heterogeneity, and risk of bias.

Results: A total of 164 studies were included, allowing pooled analysis of 31 potential prognostic factors. In the univariable analysis, the evidence for extensive disease was classified as strong while evidence for low-grade dysplasia, strictures, primary sclerosing cholangitis, post-inflammatory polyps, family history of CRC, and ulcerative colitis versus Crohn's disease was considered moderate. Evidence for any dysplasia, colon segment resection, aneuploidy, male sex, and age was classified as weak. In addition, histologic inflammation was identified as a risk factor in multivariable analysis (weak evidence). The evidence for the protective factors colonoscopic surveillance, 5-Aminosalicylic Acid, thiopurines, and smoking was moderate in univariable analysis. Multivariable analysis provided weak evidence for statin use.

Conclusions: In this systematic review and meta-analysis, we identified 13 risk factors and 5 protective factors for aCRN in IBD patients, based on univariable and/or multivariable pooled analyses. These findings might lay the groundwork for an improved CRC risk stratification-based surveillance in IBD.

Keywords: Colorectal Cancer; Protective Factor; Risk Factor; Ulcerative Colitis.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Colitis, Ulcerative / diagnosis
  • Colitis, Ulcerative / epidemiology*
  • Colitis, Ulcerative / therapy
  • Colitis-Associated Neoplasms / diagnosis
  • Colitis-Associated Neoplasms / epidemiology*
  • Colitis-Associated Neoplasms / mortality
  • Colorectal Neoplasms / diagnosis
  • Colorectal Neoplasms / epidemiology*
  • Colorectal Neoplasms / mortality
  • Crohn Disease / diagnosis
  • Crohn Disease / epidemiology*
  • Crohn Disease / therapy
  • Humans
  • Neoplasm Grading
  • Prognosis
  • Protective Factors
  • Risk Assessment
  • Risk Factors