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Inflammatory bowel diseases (IBD) are associated with an increased risk of gastrointestinal cancers depending on the specific type of IBD, the extent of the disease and its location. Patients with IBD and extensive colonic involvement are at increased risk of colorectal cancer whereas patients with Crohn disease have an increased risk for small-bowel and anal carcinoma. These cancers preferentially develop on sites of longstanding inflammation. In regards to colon cancer, several key pathogenic events are involved, including chromosomal instability, microsatellite instability and hypermethylation. The risk for colon cancer in IBD patients correlates with longer disease duration, presence of sclerosing cholangitis, pancolitis, family history of colorectal cancer, early onset of the disease and severity of bowel inflammation. Identification of increased colorectal cancer risk in individual IBD patients has led to formal surveillance guidelines. Conversely, although an increased risk for other types of cancer has been well identified, no specific formal screening recommendations exist. Consequently, the role of the radiologist is crucial to alert the referring gastroenterologist when a patient with IBD presents with unusual imaging findings at either computed tomography (CT) or magnetic resonance (MR) imaging. This review provides an update on demographics, molecular, clinical and histopathological features of gastrointestinal cancers in IBD patients including colorectal carcinoma, small bowel adenocarcinoma, neuroendocrine tumors and anal carcinoma, along with a special emphasis on the current role of CT and MR imaging. [ABSTRACT FROM AUTHOR]

Background: Immunotherapies still fail to benefit colorectal cancer (CRC) patients. Relevant functional assays aimed at studying these failures and the efficacy of cancer immunotherapy in human are scarce. 3D tumor cultures, called tumor organoids or spheroids, represent interesting models to study cancer treatments and could help to challenge these issues. Methods: We analyzed heterotypic cocultures of human colon tumor-derived spheroids with immune cells to assess the infiltration, activation and function of T and NK cells toward human colorectal tumors in vitro. Results: We showed that allogeneic T and NK cells rapidly infiltrated cell line-derived spheroids, inducing immunemediated tumor cell apoptosis and spheroid destruction. NKG2D, a key activator of cytotoxic responses, was engaged on infiltrating cells. We thus assessed the therapeutic potential of an antibody targeting the specific ligands of NKG2D, MICA and MICB, in this system. Anti-MICA/B enhanced immune-dependent destruction of tumor spheroid by driving an increased NK cells infiltration and activation. Interestingly, tumor cells reacted to immune infiltration by upregulating HLA-E, ligand of the inhibitory receptor NKG2A expressed by CD8 and NK cells. NKG2A was increased after anti-MICA/B treatment and, accordingly, combination of anti-MICA/B and anti-NKG2A was synergistic. These observations were ultimately confirmed in a clinical relevant model of coculture between CRC patients-derived spheroids and autologous tumor-infiltrating lymphocytes. Conclusions: Altogether, we show that tumor spheroids represent a relevant tool to study tumor-lymphocyte interactions on human tissues and revealed the antitumor potential of immunomodulatory antibodies targeting MICA/B and NKG2A. [ABSTRACT FROM AUTHOR]

Background Whether aminosalicylates or thiopurines reduce the risk of colorectal cancer ( CRC) in inflammatory bowel ( IBD) disease is controversial. Aim To assess simultaneously the chemopreventive effect of aminosalicylates or thiopurines in a case-control study nested in the CESAME observational cohort that enrolled consecutive patients with IBD between May 2004 and June 2005. Patients were followed up to December 2007. Methods Study population comprised 144 case patients who developed CRC from the diagnosis of IBD (65 and 79 cases diagnosed, respectively, before and from 2004, starting year of the prospective observational period of CESAME) and 286 controls matched for gender, age, IBD subtype and year of diagnosis, and cumulative extent of colitis. Exposure to aminosalicylates or thiopurines was defined by an exposure to the treatment during the year of the diagnosis of cancer. The propensity of receiving 5- ASA and thiopurines was quantified by a composite score taking into account patient and IBD characteristics. The role of aminosalicylates or thiopurines was assessed by multivariate analysis. Propensity scores and the history of primary sclerosing cholangitis were entered into the multivariate model for adjustment. Results By multivariate analysis adjusted for propensity, a significant protective effect of exposure to drugs during the year of cancer was found for aminosalicylates ( OR = 0.587, 95% CI: 0.367-0.937, P = 0.0257), but not for thiopurines ( OR = 0.762, 95% CI: 0.432-1.343, P = 0.3468). Conclusion In a case-control study nested in the CESAME cohort, a significant decrease in the risk of colorectal cancer in IBD was associated with exposure to aminosalicylates, not to thiopurines. [ABSTRACT FROM AUTHOR]

Background: Immunotherapies still fail to benefit colorectal cancer (CRC) patients. Relevant functional assays aimed at studying these failures and the efficacy of cancer immunotherapy in human are scarce. 3D tumor cultures, called tumor organoids or spheroids, represent interesting models to study cancer treatments and could help to challenge these issues. Methods: We analyzed heterotypic cocultures of human colon tumor-derived spheroids with immune cells to assess the infiltration, activation and function of T and NK cells toward human colorectal tumors in vitro. Results: We showed that allogeneic T and NK cells rapidly infiltrated cell line-derived spheroids, inducing immune-mediated tumor cell apoptosis and spheroid destruction. NKG2D, a key activator of cytotoxic responses, was engaged on infiltrating cells. We thus assessed the therapeutic potential of an antibody targeting the specific ligands of NKG2D, MICA and MICB, in this system. Anti-MICA/B enhanced immune-dependent destruction of tumor spheroid by driving an increased NK cells infiltration and activation. Interestingly, tumor cells reacted to immune infiltration by upregulating HLA-E, ligand of the inhibitory receptor NKG2A expressed by CD8 and NK cells. NKG2A was increased after anti-MICA/B treatment and, accordingly, combination of anti-MICA/B and anti-NKG2A was synergistic. These observations were ultimately confirmed in a clinical relevant model of coculture between CRC patients-derived spheroids and autologous tumor-infiltrating lymphocytes. Conclusions: Altogether, we show that tumor spheroids represent a relevant tool to study tumor-lymphocyte interactions on human tissues and revealed the antitumor potential of immunomodulatory antibodies targeting MICA/B and NKG2A. [ABSTRACT FROM AUTHOR]