This review considers why current strategies for surveillance and the prevention of colorectal cancer as a long‐term complication are ineffective. The role of endoscopists, pathologists, and patients are investigated. Colorectal cancer is linked to poor compliance with therapy, and attention may be better directed at improving adherence to treatment than strengthening current surveillance programs. Clearly, 5‐ASA compounds, particularly mesalazine, are the most appropriate agents to choose, but there may also be a place for the daily intake of folic acid. Currently, the evidence in support of ursodeoxycholic acid is mixed, and it cannot be recommended, in general, to patients for the prophylaxis of colorectal cancer risk. An alternative approach through better concordance with medications is considered. The situation in Crohn's colitis is less clear. Although the risk of colorectal cancer mirrors that in ulcerative colitis, there are no published community‐based studies that exclusively assess the effects of surveillance on the early detection of cancer, and the benefits of 5‐ASA compounds in treatment seem less certain than in ulcerative colitis. In addition, there have been no assessments of the effects of any medications on cancer risk in Crohn's disease.

AIM: To determine whether aspirin or non-aspirin non-steroidal anti-inflammatory drugs (NA-NSAIDs) prevent colorectal cancer (CRC) in patients with inflammatory bowel disease (IBD).

METHODS: We performed a systematic review and meta-analysis. We searched for articles reporting the risk of CRC in patients with IBD related to aspirin or NA-NSAID use. Pooled odds ratios (OR) and 95%CIs were determined using a random-effects model. Publication bias was assessed using Funnel plots and Egger’s test. Heterogeneity was assessed using Cochran’s Q and the I² statistic.

RESULTS: Eight studies involving 14917 patients and 3 studies involving 1282 patients provided data on the risk of CRC in patients with IBD taking NA-NSAIDs and aspirin respectively. The pooled OR of developing CRC after exposure to NA-NSAIDs in patients with IBD was 0.80 (95%CI: 0.39-1.21) and after exposure to aspirin it was 0.66 (95%CI: 0.06-1.39). There was significant heterogeneity (I² > 50%) between the studies. There was no change in the effect estimates on subgroup analyses of the population studied or whether adjustment or matching was performed.

CONCLUSION: There is a lack of high quality evidence on this important clinical topic. From the available evidence NA-NSAID or aspirin use does not appear to be chemopreventative for CRC in patients with IBD.

• Inflammatory bowel disease
• Aspirin
• Non-steroidal anti-inflammatory
• Colorectal cancer
• Chemoprevention

• Anti-Inflammatory Agents, Non-Steroidal/therapeutic use
• Anticarcinogenic Agents/therapeutic use
• Aspirin/therapeutic use
• Colorectal Neoplasms/diagnosis
• Colorectal Neoplasms/etiology
• Colorectal Neoplasms/prevention & control
• Evidence-Based Medicine
• Humans
• Inflammatory Bowel Diseases/complications
• Inflammatory Bowel Diseases/diagnosis
• Inflammatory Bowel Diseases/drug therapy
• Odds Ratio
• Risk Factors

• MR/L01629X/1 Medical Research Council