Chemopreventive effects of 5-aminosalicylic acid on inflammatory bowel disease-associated colorectal cancer and dysplasia: a systematic review with meta-analysis

Oncotarget. 2017 Jan 3;8(1):1031-1045. doi: 10.18632/oncotarget.13715.

Abstract

Background and aims: The chemopreventive effect of 5-aminosalicylic acid (5-ASA) in patients with inflammatory bowel disease (IBD) has been widely studied; however, the results remain conflicting. The aim of this study was to systematically review the literature and update evidence concerning effects of 5-ASA on the risk of colorectal cancer (CRC) and dysplasia (Dys) in patients with ulcerative colitis (UC) or Crohn's disease (CD).

Results: 5-ASA showed a chemopreventive effect against CRC/Dys in IBD patients (OR = 0.58, 95% CI: 0.45-0.75). However, this effect was significant only in clinical-based studies (OR = 0.51; 95% CI: 0.39-0.65), but not in population-based studies (OR = 0.71; 95% CI: 0.46-1.09). Moreover, this effect was noticeable in patients with UC (OR = 0.46, 95% CI: 0.34-0.61), but not in CD (OR = 0.66, 95% CI: 0.42-1.03), and on the outcome of CRC (OR = 0.54, 95% CI: 0.39-0.74), but not Dys (OR = 0.47; 95% CI: 0.20-1.10). In IBD patients, mesalazine dosage ≥ 1.2 g/day showed greater protective effects against CRC/Dys than dosages < 1.2 g/day. However, Sulphasalazine therapy did not show any noticeable protective function regardless of the dosage administered.

Materials and methods: We performed a systematic review with a meta-analysis of 26 observational studies involving 15,460 subjects to evaluate the risks of developing CRC and Dys in IBD patients receiving 5-ASA treatment. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each evaluation index.

Conclusions: 5-ASA has a chemopreventive effect on CRC (but not Dys) in IBD patients. Moreover, UC patients can benefit more from 5-ASA than CD patients. Mesalazine maintenance dosage ≥ 1.2 g/day is an effective treatment for reducing CRC risk in IBD patients.

Keywords: 5-Aminosalicylic acid; chemopreventive effect; colorectal cancer; dysplasia; inflammatory bowel disease.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use*
  • Chemoprevention
  • Cohort Studies
  • Colorectal Neoplasms / etiology*
  • Colorectal Neoplasms / prevention & control*
  • Humans
  • Hyperplasia
  • Inflammatory Bowel Diseases / complications*
  • Inflammatory Bowel Diseases / drug therapy*
  • Inflammatory Bowel Diseases / pathology
  • Mesalamine / therapeutic use*
  • Odds Ratio
  • Population Surveillance
  • Publication Bias
  • Risk Assessment
  • Risk Factors

Substances

  • Anti-Inflammatory Agents, Non-Steroidal
  • Mesalamine