Objective: To determine the validity and safety of selective cyclooxygenase (COX)-2 inhibitors for the prevention of colorectal adenomas.
Methods: The relevant data were retrieved from Medline (1966 to 2006), OVID (1996 to January 2007), EMBASE (1980 to January 2007), Chinese Cochrane Centre databases (up to January 2007) and Chinese Biological Medicine Disk (CBM disk, 1997 to 2007). Methodological quality assessment was based on the Cochrane Reviewers' Handbook and Jadad's Score Scale. Statistical software RevMan4.2 was used for meta-analysis.
Results: Six randomized clinical trials (5708 patients) were included in the study. Compared with placebo, selective COX-2 inhibitors lowered the detection rates of both adenomas and advanced adenomas (RR: 0.70, 95% CI: 0.55 - 0.88, P = 0.0003 and RR: 0.69, 95% CI: 0.53 - 0.89, P = 0.005). No significant difference was observed in the number of adverse events between patients taking selective COX-2 inhibitors and those taking placebo (RR: 1.07, 95% CI: 0.98 - 1.17, P = 0.11). Compared with placebo, selective COX-2 inhibitors increased the risk of cardiovascular events (RR: 1.21, 95% CI: 1.09 - 1.33, P = 0.0002).
Conclusion: Selective COX-2 inhibitors can induce sufficient regression of colorectal adenomatous polyps and thus be used for chemoprevention of colorectal neoplasms. However, because of the potential cardiovascular events, it is not routinely recommended for this indication.