Obesity Measured via Body Mass Index May Be Associated with Increased Incidence but Not Worse Outcomes of Immune-Mediated Diarrhea and Colitis

Systematic review of immune checkpoint inhibitor-related gastrointestinal, hepatobiliary, and pancreatic adverse events

Gastrointestinal immune-related adverse events (GI irAEs) are common manifestations of immune checkpoint inhibitor (ICI) toxicity. We present a comprehensive systematic review of the incidence, management, and clinical course of irAEs across the entire GI system, including the luminal GI tract, liver, and pancreas. MEDLINE, Embase, Web of Science Core Collection, and Cochrane Library were used to conduct this review. All studies pertaining to GI irAEs were included. Both abstracts and full manuscripts were eligible if they included human subjects and were written in the English language. Articles not available in English, animal studies, or research not specific to GI toxicity of immunotherapy were excluded. We excluded certain article types depending on whether stronger evidence was available in the literature for a specific toxicity, for example, if prospective studies were available on a topic, retrospective studies and case reports were excluded. We extracted a final 166 articles for our review and followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for data reporting. Risk of bias tools were not used to evaluate the extracted studies given the narrative nature of this manuscript, but each study was critically appraised by the manuscript writer. We detail the incidence, presentation, evaluation, management, and outcomes of the various GI toxicities that may arise with ICI therapy. Specifically, we discuss the characteristics of upper GI toxicity (esophagitis and gastroenteritis), lower GI toxicity (colitis), hepatobiliary inflammation, pancreatitis, and rarer forms of GI toxicity. We hope this review serves as a useful and accessible clinical tool that helps physicians familiarize themselves with the nuances of gastrointestinal/hepatic/pancreatic ICI toxicity diagnosis and management.

Immune checkpoint inhibitor colitis, a rising issue in targeted cancer therapy era: A literature review

Research advances in the oncology treatment field have led to the widespread use of immunotherapy. The usage of immune checkpoint inhibitor (ICI) has improved the survival of cancer patients with metastases. This has also led to the rapidly expanding indications for ICI use. However, ICI usage may lead to toxicity, which may be immune-related, in different organ-specific targets. The immune-related adverse events (irAEs) of ICI may lead to increased morbidity, decreased quality of life, and early termination of ICI. The clinical manifestations of irAEs in the gastrointestinal system are variable, ranging from self-limited to life-threatening or fatal events. In this review article, we would like to focus on discussing ICI-induced colitis, which is one of the most common ICI irAEs in the gastrointestinal tract.

Multifaceted effects of obesity on cancer immunotherapies: Bridging preclinical models and clinical data

Obesity, defined by excessive body fat, is a highly complex condition affecting numerous physiological processes, such as metabolism, proliferation, and cellular homeostasis. These multifaceted effects impact cells and tissues throughout the host, including immune cells as well as cancer biology. Because of the multifaceted nature of obesity, common parameters used to define it (such as body mass index in humans) can be problematic, and more nuanced methods are needed to characterize the pleiotropic metabolic effects of obesity. Obesity is well-accepted as an overall negative prognostic factor for cancer incidence, progression, and outcome. This is in part due to the meta-inflammatory and immunosuppressive effects of obesity. Immunotherapy is increasingly used in cancer therapy, and there are many different types of immunotherapy approaches. The effects of obesity on immunotherapy have only recently been studied with the demonstration of an "obesity paradox", in which some immune therapies have been demonstrated to result in greater efficacy in obese subjects despite the direct adverse effects of obesity and excess body fat acting on the cancer itself. The multifactorial characteristics that influence the effects of obesity (age, sex, lean muscle mass, underlying metabolic conditions and drugs) further confound interpretation of clinical data and necessitate the use of more relevant preclinical models mirroring these variables in the human scenario. Such models will allow for more nuanced mechanistic assessment of how obesity can impact, both positively and negatively, cancer biology, host metabolism, immune regulation, and how these intersecting processes impact the delivery and outcome of cancer immunotherapy.