Folic acid and sulfasalazine for colorectal carcinoma chemoprevention in patients with ulcerative colitis: the old and new evidence.

BACKGROUND: The purpose of the study was to assess whether folic acid supplementation and long term therapy with sulfasalazine can reduce the risk of colorectal cancer (CRC) development in longstanding extensive ulcerative colitis. MATERIAL AND METHODS: A meta-analysis was performed including the last 10 years published and Medline indexed studies on this subject. RESULTS: 3 studies have been included concerning the protective effect of folate supplementation in development of CRC. The association of these two factors is significant (effect size r =0.124, p = 0.025). The fail-safe number of studies with an opposite result should be 4 to revert the significance. 4 studies regarding sulfasalazine's protective effect in longstanding extensive ulcerative colitis have also been evaluated. A similar significance has been obtained, r = 0.148, p = 0.0007 and a fail-safe number of studies equal to 7. The homogeneity of these studies is validated by standard tests. CONCLUSIONS: Both sulfasalazine therapy and folate supplementation have a protective effect in colorectal cancer development in a population of patients with longstanding ulcerative colitis. Randomized controlled trials are needed to explore these hypotheses.