In patients with inflammatory bowel disease (IBD), chronic inflammation is a major risk factor for the development of gastrointestinal malignancies. The pathogenesis of colitis-associated cancer is distinct from sporadic colorectal carcinoma and the critical molecular mechanisms underlying this process have yet to be elucidated. Patients with IBD have also been shown to be at increased risk of developing extra-intestinal malignancies. Medical therapies that diminish the mucosal inflammatory response represent the foundation of treatment in IBD, and recent evidence supports their introduction earlier in the disease course. However, therapies that alter the immune system, often used for long durations, may also promote carcinogenesis. As the population of patients with IBD grows older, with longer duration of chronic inflammation and longer exposure to immunosuppression, there is an increasing risk of cancer development. Many of these patients will require cancer treatment, including chemotherapy, radiation, hormonal therapy, and surgery. Many patients will require further treatment for their IBD. This review seeks to explore the characteristics and risks of cancer in patients with IBD, and to evaluate the limited data on patients with IBD and cancer, including management of IBD after a diagnosis of cancer, the effects of cancer treatment on IBD, and the effect of IBD and medications for IBD on cancer outcomes.

Data on Covid-19 in patients with immune-mediated inflammatory disease who have received anticytokine biologics, other immunomodulatory therapies, or both on a long-term basis are scarce. Trials to assess the efficacy of antirheumatic therapies such as hydroxychloroquine¹ and anticytokine therapies such as interleukin-6 inhibitors² to improve outcomes in patients with Covid-19 are ongoing. The rationale for their use is that worse outcomes (i.e., hospitalization, ventilation, or death) may be related to a proinflammatory cytokine storm.^3,4

Hannah Gordon, Livia Biancone, Gionata Fiorino, Konstantinos H Katsanos, Uri Kopylov, Eman Al Sulais, Jordan E Axelrad, Karthiha Balendran, Johan Burisch, Lissy

Although microbial populations in the gut microbiome are associated with COVID-19 severity, a causal impact on patient health has not been established. Here we provide evidence that gut microbiome dysbiosis is associated with translocation of bacteria into the blood during COVID-19, causing life-threatening secondary infections. We first demonstrate SARS-CoV-2 infection induces gut microbiome dysbiosis in mice, which correlated with alterations to Paneth cells and goblet cells, and markers of barrier permeability. Samples collected from 96 COVID-19 patients at two different clinical sites also revealed substantial gut microbiome dysbiosis, including blooms of opportunistic pathogenic bacterial genera known to include antimicrobial-resistant species. Analysis of blood culture results testing for secondary microbial bloodstream infections with paired microbiome data indicates that bacteria may translocate from the gut into the systemic circulation of COVID-19 patients. These results are consistent with a direct role for gut microbiome dysbiosis in enabling dangerous secondary infections during COVID-19.

Essential tremor (ET) is a common and often progressive neurological disease, with a prevalence of approximately 4% among adults aged 40 years and older.^1-3 There have been few postmortem ET studies.^4-9 While these studies did not reveal consistent structural abnormalities, several noted mild to marked loss of Purkinje cells. However, as none of these were controlled studies (ie, there were no control brains for comparison), it was not clear whether this finding represented a normal age-related change.