Thiopurines prevent advanced colorectal neoplasia in patients with inflammatory bowel disease

Abstract

Thiopurine use protects IBD patients against the development of AN. The effect of 5-ASA appeared to be less pronounced.

The Role of Chemoprevention of Colorectal Cancer with 5-Aminosalicylates in Ulcerative Colitis

“…These findings suggest that regular evaluation of disease activity, which may include surveillance colonoscopies and adjustment of medical interventions and eventually colectomy in intractable situations are the main protective factors in this patient population and not chemoprevention by 5-ASA therapy. This is supported by a study by Rutter et al [27], which implicated the severity of colonic inflammation and not the lack of 5-ASA therapy as the most important determinant of the risk of colorectal neoplasia, and by the fact that thiopurines, which have no known chemopreventive mechanisms, also lower the risk of CRC, probably by controlling intestinal inflammation [39,46]. Bernstein et al [41] even demonstrated a higher risk for CRC with longer duration of 5-ASA therapy, suggesting that perhaps not the 5-ASA therapy itself, but the sustained need for such a therapy due to not controlled symptoms, is a driving factor for the development of colonic neoplasia (table 3).…”

“…The lack of a protective effect in the setting of dysplasia was attributed to the small sample size of only two studies comprising 96 cases. Ten more studies have been published since this meta-analysis [25,32,33,34,35,36,37,38,39,40,41]. Four of the studies were case control studies, one was a cohort study and five were population-based studies.…”

“…Over a 5-year period, neither high- nor low-dose 5-ASA therapy impeded the development of low-grade dysplasia or the progression from low- to high-grade dysplasia in this hospital-based cohort study. More recently, four large studies, two population-based and two identifying UC patients in large insurance databases, also failed to demonstrate that 5-ASA use exerts any inhibitory influence on the development of neoplasia [37,38,39,41]. …”

Previous Cancer and/or Lymphoma in Patients with Refractory IBD - Pro: Anti-TNF or Immunosuppressive Treatment

“…The risk for colorectal cancer increases with disease duration, anatomic extent of colitis and presence of other inflammatory disorders (such as primary sclerosing cholangitis), whereas it decreases when patients take drugs to reduce inflammation. Recently, two studies observed that thiopurine was associated with a decreased risk of colorectal cancer in the subgroup of IBD patients with longstanding extensive colitis [7,8]. …”

5-Aminosalicylic Acid and Chemoprevention: Does It Work?

“…There was a protective effect of 5-ASA on CRC in UC patients, with an OR of 0.52 (95% CI: 0.29-0.95; p = 0.03), but this effect was not seen among CD patients (OR 0.62, 95% CI: 0.27-1.40; p = 0.25). Main studies that evaluated the relationship between 5-ASA treatment and CRC risk in IBD are summarized in table 1 [11,15,24,25,26,27,28,32,33,34,35,36,37,38,39,40,41,42,43,44]. …”