About the Colorectal Cancer Screening and Surveillance in Crohn's Colitis

Dear Sir, Weread withinterest thecommendablestudy by Dr Basseri 1 and colleagues that focuses on the risk of developing Colorectal Cancer (CRC) in patients with Crohn's Colitis (CC). They analyzed results of screening and endoscopic surveillance in 411 patients followed from 1992 to 2009 at their institution. The study faces a yet unsolved problem and we would be pleased to suggest some observations born from a recent published clinical experience. 2 Literature shows that screening and endoscopic surveillance can be helpful in finding an early stage of CRC in patients with CC, but the efficacy in improving CRC related survival for this setting of patients is not demonstrated. This is because studies include small and heterogeneous series of patients, very often with selection bias, resulting in a low statistical evidence. It is a problem of difficult solution due to the small number of patients analyzed, that does not spare even this study. The authors affirm that the incidence of dysplasia and cancer was lower than in similarly designed study by Friedman andGillen. 3,4 They explainthatbecauseofthelowerfrequency of extensive colitis in the patient cohort (55%) compared to that of the aforementioned studies (90 and 100%), thus suggesting the extent of inflammation as risk factor for CRC development. Nevertheless, such a big difference could be explained by a dissimilarity in the inclusion criteria regarding screening and surveillance that it does not make the studies comparable. As consequence, the assertion that incidence was lower seems not correct. Moreover, the study does not consider the activity of the disease nor the relation with structuring or penetrating disease as possible variables. Additionally the lack of a control group, as well as data concerning the incidence of sporadicCRCingeneralpopulationofthesamegeographic area and its frequency of localization (distal or proximal large bowel) might create difficulties of interpretation. In this point of view the activity of the disease may result more important than the extension of the involved mucosa as a risk factor for malignant transformation, particularly if we consider the reported mean age at diagnosis of carcinoma (N55 yr). In order to incorporate the current results to clinical practice, much more knowledge would be required and the study, even if interesting and well written, does not seem to add more to the present literature.