The experience of a referral centre and literature overview of GIST and carcinoid tumours in inflammatory bowel diseases

Patients suffering from Inflammatory Bowel Diseases (IBD) are at increased risk of developing cancers of the gastrointestinal tract (GI). Adenocarcinomas are the most commonly observed GI tumours in IBD, and occur through an in inflammation-driven pathway. A trend toward reduced risk of bowel cancers has been observed in IBD in recent years, presumably related to improved medical treatments. However, some cancers may be independent from active inflammation, probably originating from altered interactions between the extremely active immune system of IBD patients and environmental factors. Data concerning gastrointestinal stromal tumours (GIST) and carcinoids tumours (CaT) of the GI in IBD patients are scanty. We report our experience with these rare cancers, and provide the readers with an overview on the topic, focussing on distinguishing and peculiar features of GIST and CaT of the GI in IBD compared with other cancer types and with general population, and address the treatment of such challenging conditions. Available data do not support an increased risk of GIST in IBD patients, but GI CaT may be more commonly observed in Crohn's disease. However, the presentation of GIST and GI CaT is protean and does not seem to be associated with disease activity in the involved GI segment in IBD. Conversely, some evidences suggest a potential role of inflammation in sustaining GI CaT in IBD. Increased awareness, longer duration of disease, and improved diagnostic modalities should also be considered when evaluating the increasing trend of CaT in CD patients. Treatment of GIST and CaT is not dissimilar from that of non-IBD patients, but prompt suspicion and diagnosis are crucial to achieve optimal outcomes.