Enterocolitis due to immune checkpoint inhibitors: a systematic review

The effect of immunotherapy PD-1 blockade on acute bone cancer pain: Insights from transcriptomic and microbiomic profiling

INTRODUCTION

The skeletal system ranks as the third most common site for cancer metastasis, often leading to pain with nociceptive and neuropathic features. Programmed cell death protein 1 (PD-1)-targeting therapeutic antibodies offer effective cancer treatment but can cause treatment-related acute pain. Understanding the mechanisms of this pain and identifying potential interventions is still a challenge.

METHODS

A murine model of bone cancer pain was established using Lewis lung carcinoma (LLC) cells, followed by intravenous administration of nivolumab, a human anti-PD-1 monoclonal antibody. Pain thresholds were measured, and micro-CT images of the skeletal system were obtained. High-throughput sequencing of the spinal cord/colon transcriptome during the acute phase of bone cancer pain and gut microbiota analysis at the end of the treatment were performed. Immunofluorescence staining and western blot experiments assessed spinal cord microglia activation and acute pain-associated molecules.

RESULTS

PD-1 inhibition with nivolumab protected against bone degradation initiated by LLC cell administration but consistently induced acute pain during nivolumab treatment. Spinal cord and colon transcriptomics revealed an immunopathological pattern during tumor progression and the acute pain phase, with notable changes in interleukin and S100 gene families. Gut microbiota analysis post-immunotherapy showed a decline in beneficial bacteria associated with short-chain fatty acid (SCFA) production. Activation of spinal cord microglia and enhanced glycolytic metabolism were confirmed as key factors in inducing acute pain following immunotherapy.

CONCLUSIONS

This study reveals that nivolumab induces acute pain by activating microglia and enhancing glycolytic metabolism in the treatment of bone cancer and uncovers connections between transcriptomic changes, gut microbiota, and acute pain following immune checkpoint blockade (ICB) treatment. It offers novel insights into the relationship between immune checkpoint blockade therapies and pain management.

Pan-cancer analysis of the immunological and oncogenic roles of ATAD2 with verification in papillary thyroid carcinoma

ATAD2 (ATPase Family AAA Domain-Containing 2) is highly expressed across varies tumor types, yet its common roles in tumor progression and immune interaction remain unclear. We analyzed the expression and alteration profiles of ATAD2, along with its diagnostic and prognostic role in pan-cancer, utilizing TCGA, GTEx, CPTAC, HPA, and cBioPortal databases. Furthermore, we examined the relationship between ATAD2 and immune infiltration utilizing single-cell sequencing data and TCGA database. Additionally, the expression and oncogenic functions of ATAD2 were verified in papillary thyroid carcinoma (PTC) through MTT, wound-healing, transwell, and flow cytometry assays. Our results revealed significant overexpression of ATAD2 in most cancers, strongly associated with poor prognosis. Amplification was the most frequent alteration type of ATAD2, with its mutation correlating with improved overall survival. ATAD2 was positively correlated with multiple inhibitory immune checkpoints and closely associated with the immunosuppressive microenvironment, particularly in PTC. In vitro experiments demonstrated that ATAD2 promoted the proliferation, migration, and invasion of PTC cells by activating the PI3K-AKT pathway and modulating the G1/S cell cycle checkpoint. Collectively, ATAD2 holds promise as a biomarker for pan-cancer diagnosis and prognosis, as well as a predictor of immunotherapeutic responsiveness and a therapeutic target to enhance the efficacy of existing anti-tumor immune therapies.

Immune checkpoint inhibitor-induced diarrhea and colitis: an overview

Immune checkpoint inhibitors (ICIs) have emerged as an integral component of the management of various cancers and have contributed to significant improvements in overall survival. Most available ICIs target anti-cytotoxic T-lymphocyte-associated protein 4 (anti-CTLA4), and anti-programmed cell death 1/programmed cell death ligand 1 (anti-PD1/PDL1). Gastrointestinal immune-related adverse events remain a common complication of ICIs. The predominant manifestations include diarrhea and colitis, which often manifest concurrently as immune-mediated diarrhea and colitis (IMDC). Risk factors for developing these side effects include baseline gut microbiota, preexisting autoimmune disorders, such as inflammatory bowel disease, and type of neoplasm. The hallmark symptom of colitis is diarrhea which may be accompanied by mucus or blood in stools. Patients may also experience abdominal pain, fever, vomiting, and nausea. If not treated rapidly, ICI-induced colitis can lead to serious life-threatening complications. Current management is based on corticosteroids as first-line, and immunosuppressants like infliximab or vedolizumab for refractory cases. Microbiota transplantation and specific cytokines and lymphocyte replication inhibitors are being investigated. Optimal patient care requires maintaining a balance between treatment toxicity and efficacy, hence the aim of this review is to enhance readers' comprehension of the gastrointestinal adverse events associated with ICIs, particularly IMDC. In addition to identifying the risk factors, we discuss the incidence, clinical presentation, workup, and management options of IMDC.

Biomarkers associated with immune-related adverse events induced by immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) constitute a pivotal class of immunotherapeutic drugs in cancer treatment. However, their widespread clinical application has led to a notable surge in immune-related adverse events (irAEs), significantly affecting the efficacy and survival rates of patients undergoing ICI therapy. While conventional hematological and imaging tests are adept at detecting organ-specific toxicities, distinguishing adverse reactions from those induced by viruses, bacteria, or immune diseases remains a formidable challenge. Consequently, there exists an urgent imperative for reliable biomarkers capable of accurately predicting or diagnosing irAEs. Thus, a thorough review of existing studies on irAEs biomarkers is indispensable. Our review commences by providing a succinct overview of major irAEs, followed by a comprehensive summary of irAEs biomarkers across various dimensions. Furthermore, we delve into innovative methodologies such as machine learning, single-cell RNA sequencing, multiomics analysis, and gut microbiota profiling to identify novel, robust biomarkers that can facilitate precise irAEs diagnosis or prediction. Lastly, this review furnishes a concise exposition of irAEs mechanisms to augment understanding of irAEs prediction, diagnosis, and treatment strategies.

Inflammatory Bowel Disease and Colorectal Cancer

Patients with inflammatory bowel diseases (IBDs), including both ulcerative colitis (UC) and Crohn's disease (CD), are at a higher risk of developing colorectal cancer (CRC). However, advancements in endoscopic imaging techniques, integrated surveillance programs, and improved medical therapies have led to a decrease in the incidence of CRC among IBD patients. Currently, the management of patients with IBD who have a history of or ongoing active malignancy is an unmet need. This involves balancing the risk of cancer recurrence/progression with the potential exacerbation of IBD if the medications are discontinued. The objective of this review is to provide an updated summary of the epidemiology, causes, risk factors, and surveillance approaches for CRC in individuals with IBD, and to offer practical guidance on managing IBD patients with history of previous or active cancer.

Pan-cancer analysis and single-cell analysis reveals FAM110B as a potential target for survival and immunotherapy

Background: FAM110B belongs to the family that has a 110 sequence similarity (FAM110) and is located in the centrosome and mitotic spindle. FAM110B has been linked to tumor cell growth in earlier research. Uncertainty exists regarding FAM110B's function within the tumor microenvironment is unclear as well as pan-cancer. Methods: In order to assess the variation in FAM110B expression within normal and pan-cancer tissues, we combined the TCGA and GTEx databases. The cBioPortal database and the GSCALite platform were used to examine the variation in genome and methylation alteration of FAM110B. Cox regression, Kaplan-Meier, and SangerBox were employed to examine the clinical features and prognosis of FAM110B and pan-cancer. The purpose of the correlational research was to investigate the associations within immunerelated genes, tumor mutation burden, microsatellite instability, immune-related genes, and immunological checkpoints and FAM110B expression. ESTIMATE, EPIC, QUANTISEQ, and MCPCOUNTER methods were used to calculate the interaction among FAM110B expression as well as the tumor immune microenvironment. The immunoinfiltration and function of FAM110B were analyzed by single-cell databases (TISCH and CancerSEA). Finally, we evaluated the sensitivity of FAM110B to small-molecule medications through GDSC and CTRP databases. Results: The transcription and protein expression of FAM110B varies significantly throughout cancer types, and this has predictive value for the prognosis of some tumors; including brain lower grade glioma (LGG), stomach adenocarcinoma (STAD), pancreatic adenocarcinoma (PAAD), etc. In the tumor microenvironment, the expression level of FAM110B was associated with immune cell infiltration, immune checkpoint immune regulatory genes, tumor mutational burden, and microsatellite fragility to a certain extent. Conclusion: This work investigates the possibility of utility of FAM110B as a marker to forecast pan-cancer immunotherapy response, providing a theoretical basis for cancer therapy.

irAE-colitis induced by CTLA-4 and PD-1 blocking were ameliorated by TNF blocking and modulation of gut microbial

Immune-related adverse events, particularly colitis (irAE-colitis), are significant impediments to the advancement of immune checkpoint therapy. To address this, blocking TNF-α and modulating gut microbiota are effective strategies. However, their precise roles in irAE-colitis pathogenesis and potential reciprocal relationship remain unclear. An irAE-colitis model was established to evaluate the toxicity of DICB and the efficacy of Infliximab, validated through a tumor irAE-colitis mice model. Co-administration of Infliximab with DICB mitigates colitis and enhances efficacy. Analysis of fecal samples from mice reveals altered gut microbiota composition and function induced by irAE-colitis, restored by Infliximab. Notably, Bacteriodes abundance is significantly higher in irAE-colitis. Disruption of arachidonic acid and tyrosine metabolism, and steroid hormone biosynthesis is evident. Mechanistically, a regenerative feedback loop involving DICB, TNF-α and gut microbiota underlies irAE-colitis pathogenesis. In conclusion, Infliximab shows therapeutic effects against DICB toxicity, highlighting the unforeseen roles of gut microbiota and TNF-α in irAE-colitis.

Multidisciplinary management of ulcerative colitis complicated by immune checkpoint inhibitor-associated colitis with life-threatening gastrointestinal hemorrhage: A case report

BACKGROUND

Programmed cell death 1 (PD-1) inhibitors are immune checkpoint inhibitors (ICI) that have demonstrated significant efficacy in treating various advanced malignant tumors. While most patients tolerate treatment well, several adverse drug reactions, such as fatigue, myelosuppression, and ICI-associated colitis, have been reported.

CASE SUMMARY

This case involved a 57-year-old male patient with ulcerative colitis complicated by hepatocarcinoma who underwent treatment with tirelizumab (a PD-1 inhibitor) for six months. The treatment led to repeated life-threatening lower gastrointestinal hemorrhage. The patient received infliximab, vedolizumab, and other salvage procedures but ultimately required subtotal colectomy due to uncontrollable massive lower gastrointestinal bleeding. Currently, postoperative gastrointestinal bleeding has stopped, the patient's stool has turned yellow, and his full blood cell count has returned to normal.

CONCLUSION

This case highlights the necessity of early identification, timely and adequate treatment of ICI-related colitis, and rapid escalation to achieve the goal of improving prognosis.

Immune-Related Adverse Events Induced by Immune Checkpoint Inhibitors and CAR-T Cell Therapy: A Comprehensive Imaging-Based Review

Immunotherapy has revolutionized oncology care, improving patient outcomes in several cancers. However, these therapies are also associated with typical immune-related adverse events due to the enhanced inflammatory and immune response. These toxicities can arise at any time during treatment but are more frequent within the first few months. Any organ and tissue can be affected, ranging from mild to life-threatening. While some manifestations are common and more often mild, such as dermatitis and colitis, others are rarer and more severe, such as myocarditis. Management depends on the severity, with treatment being held for >grade 2 toxicities. Steroids are used in more severe cases, and immunosuppressive treatment may be considered for non-responsive toxicities, along with specific organ support. A multidisciplinary approach is mandatory for prompt identification and management. The diagnosis is primarily of exclusion. It often relies on imaging features, and, when possible, cytologic and/or pathological analyses are performed for confirmation. In case of clinical suspicion, imaging is required to assess the presence, extent, and features of abnormalities and to evoke and rule out differential diagnoses. This imaging-based review illustrates the diverse system-specific toxicities associated with immune checkpoint inhibitors and chimeric antigen receptor T-cells with a multidisciplinary perspective. Clinical characteristics, imaging features, cytological and histological patterns, as well as the management approach, are presented with insights into radiological tips to distinguish these toxicities from the most important differential diagnoses and mimickers-including tumor progression, pseudoprogression, inflammation, and infection-to guide imaging and clinical specialists in the pathway of diagnosing immune-related adverse events.

Focus on Immune Checkpoint Inhibitors-related Intestinal Inflammation: From Pathogenesis to Therapeutical Approach

Recently, antitumor immunotherapies have witnessed a breakthrough with the emergence of immune checkpoint inhibitors (ICIs) including programmed cell death-1 (PD-1), programmed cell death-ligand 1 (PD-L1), and cytotoxic T lymphocyte antigen 4 (CTLA-4) inhibitors. Unfortunately, the use of ICIs has also led to the advent of a novel class of adverse events that differ from those of classic chemotherapeutics and are more reminiscent of autoimmune diseases, the immune-related adverse events (IRAEs). Herein, we performed an insight of the main IRAEs associated with ICIs, focusing on gastroenterological IRAEs and specifically on checkpoint inhibitor colitis, which represents the most widely reported IRAE to date. We comprehensively dissected the current evidence regarding pathogenesis, diagnosis, and management of ICIs-induced colitis, touching upon also on innovative therapies.

Letter: The enigma of angiotensin receptor blocker-associated enteropathy-Authors' reply

This article is linked to Schiepatti et al papers. To view these articles, visit https://doi.org/10.1111/apt.17855 and https://doi.org/10.1111/apt.17977.

Treatment options for immune-related adverse events associated with immune checkpoint inhibitors

The immunotherapy revolution with the use of immune checkpoint inhibitors (ICIs) started with the clinical use of the first ICI, ipilimumab, in 2011. Since then, the field of ICI therapy has rapidly expanded - with the FDA approval of 10 different ICI drugs so far and their incorporation into the therapeutic regimens of a range of malignancies. While ICIs have shown high anti-cancer efficacy, they also have characteristic side effects, termed immune-related adverse events (irAEs). These side effects hinder the therapeutic potential of ICIs and, therefore, finding ways to prevent and treat them is of paramount importance. The current protocols to manage irAEs follow an empirical route of steroid administration and, in more severe cases, ICI withdrawal. However, this approach is not optimal in many cases, as there are often steroid-refractory irAEs, and there is a potential for corticosteroid use to promote tumour progression. This review surveys the current alternative approaches to the treatments for irAEs, with the goal of summarizing and highlighting the best attempts to treat irAEs, without compromising anti-tumour immunity and allowing for rechallenge with ICIs after resolution of the irAEs.

NFKB2 mediates colorectal cancer cell immune escape and metastasis in a STAT2/PD‐L1‐dependent manner

This study systematically analyzed the molecular mechanism and function of nuclear factor kappa B subunit 2 (NFKB2) in colorectal cancer (CRC) to investigate the potential of NFKB2 as a therapeutic target for CRC. Various experimental techniques, including RNA sequencing, proteome chip assays, and small molecule analysis, were used to obtain a deeper understanding of the regulation of NFKB2 in CRC. The results revealed that NFKB2 was upregulated in a significant proportion of patients with advanced hepatic metastasis of CRC. NFKB2 played an important role in promoting tumor growth through CD8+ T-cell exhaustion. Moreover, NFKB2 directly interacted with signal transducer and activator of transcription 2 (STAT2), leading to increased phosphorylation of STAT2 and the upregulation of programmed death ligand 1 (PD-L1). Applying a small molecule inhibitor of NFKB2 (Rg5) led to a reduction in PD-L1 expression and improved response to programmed death-1 blockade-based immunotherapy. In conclusion, the facilitated NFKB2-STAT2/PD-L1 axis may suppress immune surveillance in CRC and targeting NFKB2 may enhance the efficacy of immunotherapeutic strategies. Our results provide novel insights into the molecular mechanisms underlying the contribution of NFKB2 in CRC immune escape.

Psoriasis de novo or exacerbation by PD-1 checkpoint inhibitors

PD-1 (programmed Death-1) immune checkpoint inhibitors have provided significant benefits to tumor patients. However, a considerable proportion of the patients develop immune-related adverse events (irAEs), of which cutaneous irAEs (cirAEs, e.g., psoriasis) occur relatively early. This review provides an overview of the current progress in psoriasis de novo or exacerbation by PD-1 checkpoint inhibitors. It not only describes the relevant influencing factors but also theoretically analyzes the immunological mechanisms that lead to the onset or exacerbation of psoriasis. Finally, the authors present guidelines for the treatment of psoriasis de novo or exacerbation by PD-1 checkpoint inhibitors. The review is intended to assist dermatologists in the early recognition and effective individualized management of such cirAE, which is helpful to continue or adjust the tumor-targeted immunotherapy on the basis of ensuring the quality of life of tumor patients.

Efficacy and safety of chemoimmunotherapy in advanced non-small cell lung cancer patients with antibiotics-induced dysbiosis: a propensity-matched real-world analysis

PURPOSE

The gut microbiota is hypothesized as a prognostic biomarker for cancer immunotherapy. Antibiotic-induced dysbiosis negatively affects the clinical outcomes of immunotherapy. However, the effect of dysbiosis on the efficacy and safety of Chemoimmunotherapy (chemo-IOs), the frontline standard of care, in advanced non-small cell lung cancer (NSCLC) remains unknown. We aimed to compare the efficacy and safety of chemo-IOs in patients exposed to antibiotics before treatment with those of patients who were not exposed.

METHODS

We retrospectively reviewed patients with advanced NSCLC treated with first-line chemo-IOs between 2018 and 2020 at the National Cancer Center Hospital. The patients were divided into two groups: those exposed to antibiotics within 30 days before induction therapy (ABx group) and those did not antibiotics (Non-ABx group). Propensity score matching was used to control for potential confounding factors. Clinical outcomes including progression-free survival (PFS), overall survival (OS), and immune-related adverse events (irAEs) were compared.

RESULTS

Of 201 eligible patients, 21 were in the ABx group, and 42 were in the non-ABx group after propensity score matching. No differences in PFS or OS emerged between the two groups (ABx group vs. Non-ABx group) (PFS:7.0 months vs. 6.4 months, hazard ratio [HR] 0.89; 95% confidence interval [CI], 0.49-1.63, OS:20.4 months vs. 20.1 months, HR 0.87; 95% CI 0.44-1.71). The frequency of irAEs before propensity score matching was similar across any-grade irAEs (39.4% vs. 42.9%) or grade 3 or higher irAEs (9.1% vs. 11.3%).

CONCLUSION

Antibiotic-induced dysbiosis may not affect the efficacy of chemo-IOs in patients with advanced NSCLC.

Management of liver and gastrointestinal toxicity induced by immune checkpoint inhibitors: Position statement of the AEEH-AEG-SEPD-SEOM-GETECCU

The development of the immune checkpoint inhibitors (ICI) is one of the most remarkable achievements in cancer therapy in recent years. However, their exponential use has led to an increase in immune-related adverse events (irAEs). Gastrointestinal and liver events encompass hepatitis, colitis and upper digestive tract symptoms accounting for the most common irAEs, with incidence rates varying from 2% to 40%, the latter in patients undergoing combined ICIs therapy. Based on the current scientific evidence derived from both randomized clinical trials and real-world studies, this statement document provides recommendations on the diagnosis, treatment and prognosis of the gastrointestinal and hepatic ICI-induced adverse events.

Targeted Ultrasound Nanobubbles Therapy for Prostate Cancer via Immuno-Sonodynamic Effect

Background

Prostate cancer (PCa) poses a significant global health threaten. Immunotherapy has emerged as a novel strategy to augment the inhibition of tumor proliferation. However, the sole use of anti-PD-L1 Ab for PCa has not yielded improvements, mirroring outcomes observed in other tumor types.

Methods

This study employed the thin film hydration method to develop lipid nanobubbles (NBs) encapsulating chlorin e6 (Ce6) and anti-PD-L1 Ab (Ce6@aPD-L1 NBs). Our experimental approach included cellular assays and mouse immunization, providing a comprehensive evaluation of Ce6@aPD-L1 NBs' impact.

Results

The Ce6@aPD-L1 NBs effectively induced reactive oxygen species generation, leading to tumor cells death. In mice, they demonstrated a remarkable enhancement of immune responses compared to control groups. These immune responses encompassed immunogenic cell death induced by sonodynamic therapy and PD-1/PD-L1 blockade, activating dendritic cells maturation and effectively stimulating CD8+T cells.

Conclusion

Ce6@aPD-L1 NBs facilitate tumor-targeted delivery, activating anti-tumor effects through direct sonodynamic therapy action and immune system reactivation in the tumor microenvironment. Ce6@aPD-L1 NBs exhibit substantial potential for achieving synergistic anti-cancer effects in PCa.

Univariable and multivariable Mendelian randomization study identified the key role of gut microbiota in immunotherapeutic toxicity

BACKGROUND

In cancer patients receiving immune checkpoint inhibitors (ICIs), there is emerging evidence suggesting a correlation between gut microbiota and immune-related adverse events (irAEs). However, the exact roles of gut microbiota and the causal associations are yet to be clarified.

METHODS

To investigate this, we first conducted a univariable bi-directional two-sample Mendelian randomization (MR) analysis. Instrumental variables (IVs) for gut microbiota were retrieved from the MiBioGen consortium (18,340 participants). GWAS summary data for irAEs were gathered from an ICIs-treated cohort with 1,751 cancer patients. Various MR analysis methods, including inverse variance weighted (IVW), MR PRESSO, maximum likelihood (ML), weighted median, weighted mode, and cML-MA-BIC, were used. Furthermore, multivariable MR (MVMR) analysis was performed to account for possible influencing instrumental variables.

RESULTS

Our analysis identified fourteen gut bacterial taxa that were causally associated with irAEs. Notably, Lachnospiraceae was strongly associated with an increased risk of both high-grade and all-grade irAEs, even after accounting for the effect of BMI in the MVMR analysis. Akkermansia, Verrucomicrobiaceae, and Anaerostipes were found to exert protective roles in high-grade irAEs. However, Ruminiclostridium6, Coprococcus3, Collinsella, and Eubacterium (fissicatena group) were associated with a higher risk of developing high-grade irAEs. RuminococcaceaeUCG004, and DefluviitaleaceaeUCG011 were protective against all-grade irAEs, whereas Porphyromonadaceae, Roseburia, Eubacterium (brachy group), and Peptococcus were associated with an increased risk of all-grade irAEs.

CONCLUSIONS

Our analysis highlights a strong causal association between Lachnospiraceae and irAEs, along with some other gut microbial taxa. These findings provide potential modifiable targets for managing irAEs and warrant further investigation.

Infliximab rescue therapy in a case of severe granulomatous colitis associated with rituximab use

Colitis occurs in about 4% of individuals treated with rituximab. Optimal management of rituximab-induced colitis, which does not improve with cessation of the drug and supportive care alone, is poorly defined due to limited evidence. Severe refractory disease can lead to colectomy. We present a case of suspected rituximab-induced colitis occurring in a woman in her 70s suffering from rheumatoid arthritis. The patient achieved full clinical, endoscopic and histological remission of colitis with infliximab therapy. The use of biological therapy to treat rituximab-induced colitis can be a potentially organ-saving rescue therapy; however, it must be balanced against the increased risks of immunosuppression in patients already exposed to rituximab. While more evidence is required to fully understand the efficacy and risks of antitumour necrosis factor therapy in this scenario, our case provides an example of the successful use of infliximab for rituximab-induced colitis, which likely helped the patient avoid a colectomy.

New strategies in the diagnosis and treatment of immune-checkpoint inhibitor-mediated colitis

Immune-checkpoint inhibitor-mediated colitis (IMC) is an increasingly recognized adverse event in cancer immunotherapy, particularly associated with immune checkpoint inhibitors (ICIs) such as anti-cytotoxic T-lymphocyte antigen-4 and anti-programmed cell death protein-1 antibodies. As this revolutionary immunotherapy gains prominence in cancer treatment, understanding, diagnosing, and effectively managing IMC becomes paramount. IMC represents a unique challenge due to its immune-mediated nature and potential for severe complications. However, a precise picture of IMC pathophysiology is currently unavailable. Therefore, we aimed to summarize the existing data while acknowledging the need for further research. This comprehensive review explores the mechanisms underlying ICIs, gastrointestinal adverse effects, and, in particular, IMC's incidence, prevalence, and features. Our review also emphasizes the importance of recognizing IMC's distinct clinical and histopathological features to differentiate it from other forms of colitis. Furthermore, this paper highlights the urgent need for evolving diagnostic methods, therapeutic strategies, and a multidisciplinary approach to effectively manage IMC.

Gut microbiota: A double-edged sword in immune checkpoint blockade immunotherapy against tumors

Tumor cells can evade immune surveillance by expressing immune checkpoint molecule ligands, resulting in effective immune cell inactivation. Immune checkpoint blockades (ICBs) have dramatically improved survival of patients with multiple types of cancers. However, responses to ICB immunotherapy are heterogeneous with lower patient response rates. The advances have established that the gut microbiota can be as a promising target to overcome resistance to ICB immunotherapy. Furthermore, some bacterial species have shown to promote improved responses to ICBs. However, gut microbiota is critical in maintaining gut and systemic immune homeostasis. It not only promotes differentiation and function of immunosuppressive immune cells but also inhibits inflammatory cells via gut microbiota derived products such as short chain fatty acids (SCFAs), tryptophan (Trp) and bile acid (BA) metabolites, which play an important role in tumor immunity. Since the gut microbiota can either inhibit or enhance immune against tumor, it should be a double-edged sword in ICBs against tumor. In this review, we discuss the effects of gut microbiota on immune cells and also tumor cells, especially enhances of gut microbiota on ICB immunotherapy. These discussions can hopefully promote the development of ICB immunotherapy.

Management of liver and gastrointestinal toxicity induced by immune checkpoint inhibitors: Position statement of the AEEH-AEG-SEPD-SEOM-GETECCU

The development of the immune checkpoint inhibitors (ICI) is one of the most remarkable achievements in cancer therapy in recent years. However, their exponential use has led to an increase in immune-related adverse events (irAEs). Gastrointestinal and liver events encompass hepatitis, colitis and upper digestive tract symptoms accounting for the most common irAEs, with incidence rates varying from 2 % to 40 %, the latter in patients undergoing combined ICIs therapy. Based on the current scientific evidence derived from both randomized clinical trials and real-world studies, this statement document provides recommendations on the diagnosis, treatment and prognosis of the gastrointestinal and hepatic ICI-induced adverse events.

A case of refractory immune checkpoint inhibitor-induced colitis improved by the treatment with vedolizumab and granulocyte-monocyte apheresis combination therapy

A 68-year-old man developed immune-related adverse event (irAE) colitis after the initiation of nivolumab and ipilimumab combination therapy for malignant melanoma. We diagnosed the patient with grade 3 irAE colitis and started prednisolone (1 mg/kg/day). Although the symptom improved once, it worsened along with the tapering of prednisolone. Therefore, we started infliximab (IFX). However, symptoms did not improve after two doses of IFX. We discontinued IFX and initiated vedolizumab (VED). Because VED alone did not improve the symptom, we started granulocyte-monocyte apheresis (GMA). Twelve weeks after the onset, the colitis was in remission. Therefore, in addition to vedolizumab, GMA may be considered in cases refractory to treatment.

Microbiota-dependent activation of CD4+ T cells induces CTLA-4 blockade-associated colitis via Fcγ receptors

Immune checkpoint inhibitors can stimulate antitumor immunity but can also induce toxicities termed immune-related adverse events (irAEs). Colitis is a common and severe irAE that can lead to treatment discontinuation. Mechanistic understanding of gut irAEs has been hampered because robust colitis is not observed in laboratory mice treated with checkpoint inhibitors. We report here that this limitation can be overcome by using mice harboring the microbiota of wild-caught mice, which develop overt colitis following treatment with anti-CTLA-4 antibodies. Intestinal inflammation is driven by unrestrained activation of IFNγ-producing CD4+ T cells and depletion of peripherally induced regulatory T cells through Fcγ receptor signaling. Accordingly, anti-CTLA-4 nanobodies that lack an Fc domain can promote antitumor responses without triggering colitis. This work suggests a strategy for mitigating gut irAEs while preserving antitumor stimulating effects of CTLA-4 blockade.

A Systematic Review of Treatment-Related Adverse Events for Combination Therapy of Multiple Tyrosine Kinase Inhibitor and Immune Checkpoint Inhibitor

BACKGROUND

Combination therapy with multiple tyrosine kinase inhibitors (multi-TKIs) and immune checkpoint inhibitors (ICIs) has been increasingly tested in clinical studies. This study aimed to investigate the effect of the addition of ICI to multi-TKIs on the profile of treatment-related adverse events.

METHODS

An electronic database search was performed using PubMed and Web of Science to identify published clinical studies on multi-TKI monotherapy and multi-TKI plus ICI combination therapy from July 20, 2005 to July 1, 2023. The incidence rate of common adverse events caused by multi-TKI monotherapy and multi-TKI plus ICI combination therapy was obtained and compared from the viewpoints of (1) relative risk for the combination therapy vs sunitinib, (2) adverse event incidence rate by clinical trial, and (3) pooled incidence rate. The quality of the evidence was assessed with the Cochrane risk of bias tool. Meta-analysis used random effects models.

RESULTS

This systematic review identified 83 clinical studies involving 7951 patients. The combination therapy of multi-TKI and ICI was associated with an increased risk of diarrhea (relative risk [RR]: 1.24, 95% confidence interval [CI]: 1.15-1.33, P < .001), hypothyroidism (RR: 1.44, 95% CI: 1.11-1.87, P = .0064) and rash (RR: 1.71, 95% CI: 1.18-2.47, P = .0045) compared with multi-TKI monotherapy. The addition of ICI was suggested to decrease the risk of adverse events related to performance status.

CONCLUSION

Our study identified an increased risk of treatment-related adverse events associated with multi-TKI plus ICI combination therapy. This would help optimize the management of toxicities caused by multi-TKI plus ICI combination therapy.

Exploring a Rarity: Incidence of and Therapeutic Approaches for Neurological Complications and Hypophysitis in Cancer Patients on Immune Checkpoint Inhibitors-A Single-Center Study

Immune checkpoint inhibitors, such as anti-PD-1 and anti-CTLA-4 inhibitors, have become the standard of care for many cancer types. However, they induce immune-related adverse events (irAEs), including neurotoxicity and hypophysitis. The incidence and outcomes of neurotoxicity and hypophysitis in patients treated with immune checkpoint inhibitors are not well established. We conducted a retrospective study of 812 patients with solid cancers who received immune checkpoint inhibitors at the University General Hospital of Ioannina between January 2018 and January 2023. We assessed demographic and clinical data, including the severity of symptoms, treatment regimen, other irAEs, resolution type and time, and death. Two patients experienced neurotoxicity and two hypophysitis. All four patients required inpatient administration and received corticosteroids or/and hormone replacement. Three patients responded to the initial therapy, experiencing full recovery, while one patient was corticosteroid-resistant, and immunoglobin G was administered. Two patients never received immunotherapy after their toxicity due to the severity of symptoms; one patient continued monotherapy with nivolumab, changing from combination therapy with ipilimumab-nivolumab, while the fourth patient continued his initial treatment with nivolumab. Our study suggests that the incidence of neurotoxicity and hypophysitis in patients treated with immune checkpoint inhibitors is low, but careful monitoring and prompt treatment with corticosteroids are necessary for effective management.

Chemotherapy-induced ileitis associated or not with colitis in digestive oncology patients: An AGEO multicentre study

BACKGROUND

The characteristics and management of ileitis induced by chemotherapy in cancer patients are poorly described in the literature.

METHODS

This retrospective multicentre study enroled patients hospitalized in a digestive oncology unit for a symptomatic chemotherapy-induced ileitis.

RESULTS

Forty-three patients were included, with a regimen based on fluoropyrimidine and/or irinotecan in 95% of cases. Five patients were excluded due to the diagnosis of infectious ileitis (Clostridium difficile in 3 patients, Campylobacter jejuni in 1 patient and cytomegalovirus in 1 patient). The most frequently described symptoms were diarrhoea (77% including 54% of grade 3-4 diarrhoea), abdominal pain (58%), fever (51%) and vomiting (56%). An ileo-colonoscopy was performed in 35% of patients and did not show any specific results or severity criteria. The ileitis was complicated by bowel perforation and/or obstruction in 3 patients. Disease progression was favourable in 1-2 weeks in the vast majority of cases, on symptomatic treatment, allowing resumption of the chemotherapy regimen involved in 67% of patients.

CONCLUSION

Chemotherapy-induced ileitis is a rare complication that most often involves fluoropyri-midine- and/or irinotecan-based regimens. In most cases, endoscopic examinations were not contributory and do not seem useful in the event of non-severe symptomatology which most often develops favourably on symptomatic therapy, allowing resumption of the chemotherapy involved.

Impact of proton pump inhibitors on the onset of gastrointestinal immune-related adverse events during immunotherapy

INTRODUCTION

The gut microbiota (GM) can influence the pathogenesis of immune-mediated adverse events (irAEs). Proton pump inhibitors (PPIs) can affect the integrity of GM, but their role in promoting irAEs is still poorly understood.

METHODS

In this retrospective single-center cohort study, the primary endpoint was the evaluation of the incidence of gastrointestinal (GI) irAEs in cancer patients on PPIs (exposed) versus cancer patients who were not on PPIs (unexposed).

RESULTS

Three hundred and sixty three patients' records (248 M/115F, median age 69) were reviewed. Twenty-three exposed patients (92%) developed GI irAEs while only two unexposed patients (8%) developed GI irAEs (hazard ratio [HR] 13.22, 95% confidence interval [CI] 3.11-56.10, p < 0.000). This HR was confirmed after weighting for the propensity score (HR15.13 95% CI 3.22-71.03, p < 0.000).

CONCLUSION

Chronic PPI use is associated with an increased risk of GI irAES.

Severe and refractory gastrointestinal toxicity due to immune checkpoint inhibitors: clinical experience in a tertiary referral hospital

INTRODUCTION

immune checkpoint inhibitors (ICI) are increasingly used to treat several types of cancer. These drugs lead to a wide range of toxicities. Immune-related gastrointestinal adverse events are common and potentially severe. In this manuscript, we recount the real clinical experience in a tertiary center.

METHODS

a retrospective and observational study was conducted in adult patients under ICI treatment. Included patients had been referred to the Gastrointestinal Service of Hospital Universitario Vall d'Hebron for evaluation of severe toxicities, from January 2017 to January 2020, for whom the clinical, epidemiological and evolutive data were collected.

RESULTS

a total of 18 patients were included. Fifty-five percent received anti-programmed cell death protein 1 (PD-1)/anti-programmed death-ligand 1 (anti PD-L1), 11 % received anti-cytotoxic T lymphocyte antigen 4 (CTLA-4) and 33 % received both treatments. The toxicities were manifested as enterocolitis, microscopic colitis and gastritis. Upper gastrointestinal endoscopy was performed in seven patients; all were proved to have histological changes on duodenum biopsies. Treatment was stopped in all patients and steroids were initiated. Sixty-six per cent achieved clinical remission with steroids. Five patients received anti-TNF treatment (infliximab). Only one of the five had responded. Two anti-TNF refractory patients received ustekinumab, with an appropriate clinical response. One patient received apheresis granulocyte as concomitant treatment. A patient with a steroid-dependent course started vedolizumab. Three patients had other immune-related adverse events.

CONCLUSION

gastrointestinal immune-related adverse events are acquiring a higher profile in daily practice and gastroenterologists play an even greater role in the management of these patients.

Checkpoint inhibitor responses can be regulated by the gut microbiota - A systematic review

BACKGROUND

Evidence suggests that the human gut microbiota modulates the treatment response of immune checkpoint inhibitors (ICI) in cancer. Thus, finding predictive biomarkers in the fecal gut microbiota of patients who are less likely to respond to ICI would be valuable. This systematic review aimed to investigate the association between fecal gut microbiota composition and ICI-treatment response in patients with cancer.

METHODS

EMBASE, Medline, and Cochrane Library databases were searched using the "Participants, Interventions, Comparisons, and Outcomes" (PICO) process to locate studies including participants with solid cancers treated with ICI intervention. The comparator was the gut microbiota, and the outcomes were oncological outcomes such as response rates and progression-free survival. Study data were synthesized qualitatively in a systematic narrative synthesis, and the risk of bias in the studies was assessed.

RESULTS

Two reviewers screened 2092 abstracts independently, and 140 studies were read as full-text reports and assessed for eligibility. Eighteen studies were included with 775 patients with different types of solid cancers who received anti-PD-1, anti-PD-L1, or anti-CTLA-4 therapy. Distinct patterns were observed in the patients' fecal samples. Some bacterial species were reported to be present in responders and non-responders, while others were present only in one group. The most reported species associated with better prognosis were Faecalibacterium prausnitzii, Streptococcus parasanguinis, Bacteroides caccae, and Prevotella copri. In contrast, the most reported species associated with poor prognosis were Blautia obeum and Bacteroides ovatus.

CONCLUSION

Distinct microbiota features were associated with good and poor prognoses in ICI-treated patients with cancer.

Position statement on the management of the immune checkpoint inhibitor-induced colitis via multidisciplinary modified Delphi consensus

INTRODUCTION

The use of immune checkpoint inhibitors (ICIs) in cancer immunotherapy has shown increased overall survival in a wide range of cancer types with the associated risk of developing severe immune-mediated adverse events, commonly involving the gastrointestinal tract.

AIM

The aim of this position statement is to provide an updated practice advice to the gastroenterologists and oncologists on the diagnosis and management of ICI-induced gastrointestinal toxicity.

METHODOLOGY

The evidence reviewed in this paper includes a comprehensive search strategy of English language publications. Consensus was reached using a three-round modified Delphi methodology and approved by the members of the Belgian Inflammatory Bowel Disease Research and Development Group (BIRD), Belgian Society of Medical Oncology (BSMO), Belgian group of Digestive Oncology (BGDO), and Belgian Respiratory Society (BeRS).

CONCLUSIONS

The management of ICI-induced colitis requires an early multidisciplinary approach. A broad initial assessment is necessary (clinical presentation, laboratory markers, endoscopic and histologic examination) to confirm the diagnosis. Criteria for hospitalisation, management of ICIs, and initial endoscopic assessment are proposed. Even if corticosteroids are still considered the first-line therapy, biologics are recommended as an escalation therapy and as early treatment in patients with high-risk endoscopic findings.

An updated review of gastrointestinal toxicity induced by PD-1 inhibitors: from mechanisms to management

PD-1 inhibitors, as one of commonly used immune checkpoint inhibitors, enable T-cell activation and prevent immune escape by blocking the PD-1/PD-L1 signaling pathway. They have transformed the treatment landscape for cancer in recent years, due to the advantages of significantly prolonging patients' survival and improving their life quality. However, the ensuing unpredictable immune-related adverse effects (irAEs) plague clinicians, such as colitis and even potentially fatal events like intestinal perforation and obstruction. Therefore, understanding the clinical manifestations and grading criteria, underlying mechanisms, available diverse therapies, accessible biomarkers, and basis for risk stratification is of great importance for the management. Current evidence suggests that irAEs may be a marker of clinical benefit to immunotherapy in patients, so whether to discontinue PD-1 inhibitors after the onset of irAEs and rechallenge after remission of irAEs requires further evaluation of potential risk-reward ratios as well as more data from large-scale prospective studies to fully validate. At the end, the rare gastrointestinal toxicity events caused by PD-1 inhibitors are also sorted out. This review provides a summary of available data on the gastrointestinal toxicity profile caused by PD-1 inhibitors, with the aim of raising clinicians' awareness in daily practice, so that patients can safely benefit from therapy.

Immune-related adverse events of immune checkpoint inhibitors: a review

Since the first Immune Checkpoint Inhibitor was developed, tumor immunotherapy has entered a new era, and the response rate and survival rate of many cancers have also been improved. Despite the success of immune checkpoint inhibitors, resistance limits the number of patients who can achieve a lasting response, and immune-related adverse events complicate treatment. The mechanism of immune-related adverse events (irAEs) is unclear. We summarize and discuss the mechanisms of action of immune checkpoint inhibitors, the different types of immune-related adverse events and their possible mechanisms, and describe possible strategies and targets for prevention and therapeutic interventions to mitigate them.

MiRNA-Based Therapies for Lung Cancer: Opportunities and Challenges?

Lung cancer is a commonly diagnosed cancer and the leading cause of cancer-related deaths, posing a serious health risk. Despite new advances in immune checkpoint and targeted therapies in recent years, the prognosis for lung cancer patients, especially those in advanced stages, remains poor. MicroRNAs (miRNAs) have been shown to modulate tumor development at multiple levels, and as such, miRNA mimics and molecules aimed at regulating miRNAs have shown promise in preclinical development. More importantly, miRNA-based therapies can also complement conventional chemoradiotherapy, immunotherapy, and targeted therapies to reverse drug resistance and increase the sensitivity of lung cancer cells. Furthermore, small interfering RNA (siRNA) and miRNA-based therapies have entered clinical trials and have shown favorable development prospects. Therefore, in this paper, we review recent advances in miRNA-based therapies in lung cancer treatment as well as adjuvant therapy and present the current state of clinical lung cancer treatment. We also discuss the challenges facing miRNA-based therapies in the clinical application of lung cancer treatment to provide new ideas for the development of novel lung cancer therapies.

Gastrointestinal treatment-related adverse events of combined immune checkpoint inhibitors: a meta-analysis

Introduction: Combined immune checkpoint inhibitors can cause gastrointestinal adverse events. Methods: We performed a meta-analysis of pooled colonic, hepatic and pancreatic treatment-related adverse events of combined ICI. Results: 53 trials reporting treatment-related adverse events in 6581 patients. All grade diarrhea was the most common adverse event seen in 25.4% patients, followed by all grade hepatitis in nearly 13% patients and pancreatitis in nearly 7.5% patients. Conclusion: Our study provides pooled data of treatment-related adverse events from different combination immune checkpoint inhibitors use in solid tumors and demonstrates a high incidence of all grades and ≥3 grade gastrointestinal adverse events. Further studies are required to characterize these adverse events and assess their overall impact on treatment course and outcomes.

The progress on the relationship between gut microbiota and immune checkpoint blockade in tumors

Immune checkpoint blockade (ICB) has emerged as a promising immunotherapeutic approach for the treatment of various tumors. However, the efficacy of this therapy is limited in a subset of patients, and it is important to develop strategies to enhance immune responses. Studies have demonstrated a critical role of gut microbiota in regulating the therapeutic response to ICB. Gut microbiota composition, diversity, and function are mediated by metabolites, such as short-chain fatty acids and secondary bile acids, that interact with host immune cells through specific receptors. In addition, gut bacteria may translocate to the tumor site and stimulate antitumor immune responses. Therefore, maintaining a healthy gut microbiota composition, for instance through avoiding the use of antibiotics or probiotic interventions, can be an effective approach to optimize ICB therapy. This review summarizes the current understanding of the microbiota-immunity interactions in the context of ICB therapy, and discusses potential clinical implications of these findings.

Gastrointestinal and Hepatobiliary Immune-related Adverse Events: A Histopathologic Review

Immune checkpoint inhibitors have been increasingly used to treat various malignant neoplasms. Despite their superior efficacy in treating certain ones, their global immune-activation effect leads to systemic side effects, referred to as immune-related adverse events. Immune-related adverse events affect a variety of organs, including the skin, gastrointestinal, hepatobiliary, and endocrine organs. Gastrointestinal tract immune-related adverse events present with a wide range of symptoms with variable severity, which may lead to treatment interruption and administration of immunosuppression therapy in many cases. Histopathologic changes are diverse, overlapping with many other conditions. Therefore, recognizing these changes is crucial in diagnosing immune-related adverse events. This review discusses the pathologic manifestations of gastrointestinal immune-related adverse events and discusses the primary differential diagnoses.

High expression of RNF31 is associated with tumor immune cell infiltration and leads to poor prognosis in liver hepatocellular carcinoma

Ring finger protein 31 (RNF31) has been found to play an important role in tumor immunity. However, the role of RNF31 in liver hepatocellular carcinoma (LIHC) has not been reported. Therefore, we investigated the expression and prognostic value of RNF31 in patients with LIHC and explored its relationship with immune cell infiltration. The Cancer Genome Atlas liver hepatocellular carcinoma (TCGA-LIHC) dataset was downloaded to analyse the impact of RNF31 on the prognosis and immune cell infiltration of LIHC. The Tumor Immune Estimation Resource (TIMER) database was used to analyse the correlation between RNF31 and tumor immune cell infiltration in LIHC. Additionally, we analysed the relationship between RNF31 and tumor necrosis factor (TNF) as well as the interferon-gamma (IFN-γ) signaling pathway. The expression of RNF31 in LIHC was significantly higher than that in normal tissues. Increased RNF31 expression was associated with decreased overall survival (OS) and relapse-free survival (RFS). An increase in RNF31 expression was closely related to the infiltration levels of immune cells (e.g., natural killer (NK) cells, CD8 + T cells, and B cells). RNF31 was also positively correlated with the expression of immune checkpoint genes in LIHC. Moreover, RNF31 may participate in TNF and IFN-γ signaling pathways. In conclusion, RNF31 is a potentially valuable prognostic biomarker in LIHC. RNF31 is also associated with immune cell infiltration in LIHC. RNF31 may be a potential target for immunotherapy of LIHC.

Pan-Cancer Analysis Reveals PPRC1 as a Novel Prognostic Biomarker in Ovarian Cancer and Hepatocellular Carcinoma

Background and Objectives: As is well understood, peroxisome proliferator-activated receptor gamma cofactor-related 1 (PPRC1) plays a central role in the transcriptional control of the mitochondrial biogenesis and oxidative phosphorylation (OXPHOS) process, yet its critical role in pan-cancer remains unclear. Materials and Methods: In this paper, the expression levels of PPRC1 in different tumor tissues and corresponding adjacent normal tissues were analyzed based on four databases: The Genotype-Tissue Expression (GTEx), Cancer Cell Line Encyclopedia (CCLE), The Cancer Genome Atlas (TCGA), and Tumor Immune Estimation Resource (TIMER). Meanwhile, the prognostic value of PPRC1 was inferred using Kaplan-Meier plotter and forest-plot studies. In addition, the correlation between PPRC1 expression and tumor immune cell infiltration, immune checkpoints, and the tumor-stemness index was analyzed using TCGA and TIMER databases. Results: According to our findings, the expression level of PPRC1 was found to be different in different cancer types and there was a positive correlation between PPRC1 expression and prognosis in several tumor types. In addition, PPRC1 expression was found to be significantly correlated with immune cell infiltration, immune checkpoints, and the tumor-stemness index in both ovarian and hepatocellular carcinoma. Conclusions: PPRC1 demonstrated promising potential as a novel biomarker in pan-cancer due to its potential association with immune cell infiltration, expression of immune checkpoints, and the tumor-stemness index.

Severe colitis in patients with melanoma treated with BRAF/MEK inhibitors

BACKGROUND AND AIMS

Dual blockade of BRAF and MEK kinases is a standard of care for metastatic V600E/K BRAF mutant melanoma. This study reports the first systematic description of colitis due to BRAF and MEK inhibitors.

METHODS

We studied consecutive patients with melanoma, treated with BRAF and MEK inhibitors, who had colitis requiring hospitalisation. Electronic files were studied; endoscopic biopsies and colectomy specimens were read centrally.

RESULTS

Between January 2021 and March 2022, nine women and one man, aged 50-90 years, were studied. Nine patients received encorafenib and binimetinib; one patient received dabrafenib and trametinib. The main symptoms were diarrhoea, haematochezia, abdominal pain and intestinal obstruction. Blood tests showed anaemia, increased CRP and low serum albumin levels in most patients. All patients had ulcerations of the right colon with (2/10) or without (8/10) stenosis of the ileocecal valve, and 4/10 patients also had ulcerations distal to the right colon. Histopathological findings were suggestive of ischaemia and mild inflammation. Nine of the 10 patients discontinued BRAF/MEK inhibitors. Drugs were reintroduced in four patients, three of whom had a severe relapse of diarrhoea. Two patients required surgery and underwent intestinal resection. One patient died of enterocolitis.

CONCLUSION

BRAF/MEK inhibitors can induce severe colitis characterised by ulcerations of the right colon.

The Optimal Management of Inflammatory Bowel Disease in Patients with Cancer

Patients with inflammatory bowel disease (IBD) have an increased risk of cancer secondary to chronic inflammation and long-term use of immunosuppressive therapy. With the aging IBD population, the prevalence of cancer in IBD patients is increasing. As a result, there is increasing concern about the impact of IBD therapy on cancer risk and survival, as well as the effects of cancer therapies on the disease course of IBD. Managing IBD in patients with current or previous cancer is challenging since clinical guidelines are based mainly on expert consensus. Evidence is rare and mainly available from registries or observational studies. In contrast, excluding patients with previous/or active cancer from clinical trials and short-term follow-up can lead to an underestimation of the cancer or cancer recurrence risk of approved medications. The present narrative review aims to summarize the current evidence and provide practical guidance on the management of IBD patients with cancer.

Immunogenetic variations predict immune-related adverse events for PD-1/PD-L1 inhibitors

BACKGROUND

PD-1/PD-L1 inhibitors have brought remarkable benefits but can cause profound immune-related adverse events (irAEs). The host immunogenetic background is likely to play a role in irAE susceptibility. In this study, we aimed to identify potential immunogenetic biomarkers to predict irAEs.

METHODS

Patients with solid tumours receiving PD-1/PD-L1 blockade were recruited and followed up. Genes considered pivotal contributors to tumour-immunity and autoimmune diseases were screened out via protein-protein interaction network and Cytoscape. Consequently, thirty-nine variants in eighteen genes were genotyped using the multiplex genotyping assay. Association analysis between genetic variants and irAEs as well as irAEs-free survival was performed.

RESULTS

Four immunogenetic variants as predictive biomarkers of irAEs were identified. The C allele of Mitogen-Activated Protein Kinase 1 (MAPK1) rs3810610 (odds ratio [OR] = 1.495, 95% confidence interval [CI] = 1.093-2.044, P = 0.012) was a risk predictor while the A allele of PTPRC rs6428474 (OR = 0.717, 95% CI = 0.521-0.987, P = 0.041) was a protective factor for all-grade irAEs. The A allele of ADAD1 rs17388568 (OR = 2.599, 95% CI = 1.355-4.983, P = 0.003) increased the risk while the G allele of IL6 rs1800796 (OR = 0.425, 95% CI = 0.205-0.881, P = 0.018) protected patients from high-grade irAEs. Significant immunogenetic variants reached a similar tendency in PD-1 blockade or lung cancer subgroups. In multivariate Cox regression analysis, the MAPK1 rs3810610 was an independent factor regarding all-grade irAEs-free survival (CC versus CT or TT: hazard ratio [HR] = 0.71, 95% CI = 0.52-0.99, P = 0.042). ADAD1 rs17388568 (AA versus AG or GG: HR = 0.11, 95% CI = 0.025-0.49, P = 0.004) and IL6 rs1800796 (GG or GC versus CC: HR = 3.10, 95% CI = 1.315-7.29, P = 0.01) were independent variables for high-grade irAEs-free survival.

CONCLUSION

We first identified several immunogenetic polymorphisms associated with irAEs and irAEs-free survival in PD-1/PD-L1 blockade-treated tumour patients, and they may serve as potential predictive biomarkers.

Comprehensive Pan-Cancer Analysis of KIF18A as a Marker for Prognosis and Immunity

KIF18A belongs to the Kinesin family, which participates in the occurrence and progression of tumors. However, few pan-cancer analyses have been performed on KIF18A to date. We used multiple public databases such as TIMER, The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), and Human Protein Atlas (HPA) to explore KIF18A mRNA expression in 33 tumors. We performed immunohistochemistry on liver cancer and pancreatic cancer tissues and corresponding normal tissues to examine the expression of KIF18A protein. Univariate Cox regression and Kaplan-Meier survival analysis were applied to detect the effect of KIF18A on overall survival (OS), disease-specific survival (DSS), and progression-free interval (PFI) of patients with these tumors. Subsequently, we explored KIF18A gene alterations in different tumor tissues using cBioPortal. The relationship between KIF18A and clinical characteristics, tumor microenvironment (TME), immune regulatory genes, immune checkpoints, tumor mutational burden (TMB), microsatellite instability (MSI), mismatch repairs (MMRs), DNA methylation, RNA methylation, and drug sensitivity was applied for further study using the R language. Gene Set Enrichment Analysis (GSEA) was utilized to explore the molecular mechanism of KIF18A. Bioinformatic analysis and immunohistochemical experiments confirmed that KIF18A was up-regulated in 27 tumors and was correlated with the T stage, N stage, pathological stage, histological grade, and Ki-67 index in many cancers. The overexpression of KIF18A had poor OS, DSS, and PFI in adrenocortical carcinoma (ACC), kidney renal clear cell carcinoma (KIRC), kidney renal papillary cell carcinoma (KIRP), brain lower-grade glioma (LGG), liver cancer (LIHC), lung adenocarcinoma (LUAD), and pancreatic cancer (PAAD). Univariate and multivariate regression analysis confirmed KIF18A as an independent prognostic factor for LIHC and PAAD. The mutation frequency of KIF18A is the highest in endometrial cancer. KIF18A expression levels were positively associated with immunocyte infiltration, immune regulatory genes, immune checkpoints, TMB, MSI, MMRs, DNA methylation, RNA methylation, and drug sensitivity in certain cancers. In addition, we discovered that KIF18A participated in the cell cycle at the single-cell level and GSEA analysis for most cancers. These findings suggested that KIF18A could be regarded as a latent prognostic marker and a new target for cancer immunological therapy.

Drug-induced digestive tract injury: decoding some invisible offenders

There is an ever-growing list of pharmacological agents, several of which are attributed to cause clinically significant gastrointestinal (GI) injury. Many patients present with significant but nonspecific symptoms, that in conjunction with the absence of relevant drug history on the requisition slip can make the histopathologic diagnosis challenging. To complicate this, although some drugs have relatively characteristic histopathologic features (such as doxycycline), there exist many other drugs that exhibit wide and varying spectra of histopathologic findings (such as immune checkpoint inhibitors or olmesartan) and have histomorphologic overlap with many other commonly encountered disease entities. This review discusses the histopathologic features of some relatively recently described drugs causing GI tract injury, namely doxycycline, tacrolimus, mycophenolate, immune checkpoint inhibitors, and olmesartan. We also discuss the common mimics in histopathologic differential and some pearls that can help distinguish GI tract injury induced by the aforementioned drugs from its mimics. Awareness of the wide spectra of histopathologic changes associated with these drugs is crucial for practicing pathologists, to avoid misdiagnosis and guiding the clinician for an optimal patient management, which usually involves modifying or discontinuing the offending drug. Needless to say, once a diagnosis of drug-induced injury is suspected, clinicopathologic correlation including corroboration with the drug history is of utmost importance as is the exclusion of dual pathology in these patients.

Implication of the Gut Microbiome and Microbial-Derived Metabolites in Immune-Related Adverse Events: Emergence of Novel Biomarkers for Cancer Immunotherapy

Immune checkpoint inhibitors (ICIs) have changed how we think about tumor management. Combinations of anti-programmed death ligand-1 (PD-L1) immunotherapy have become the standard of care in many advanced-stage cancers, including as a first-line therapy. Aside from improved anti-tumor immunity, the mechanism of action of immune checkpoint inhibitors (ICIs) exposes a new toxicity profile known as immune-related adverse effects (irAEs). This novel toxicity can damage any organ, but the skin, digestive and endocrine systems are the most frequently afflicted. Most ICI-attributed toxicity symptoms are mild, but some are severe and necessitate multidisciplinary side effect management. Obtaining knowledge on the various forms of immune-related toxicities and swiftly changing treatment techniques to lower the probability of experiencing severe irAEs has become a priority in oncological care. In recent years, there has been a growing understanding of an intriguing link between the gut microbiome and ICI outcomes. Multiple studies have demonstrated a connection between microbial metagenomic and metatranscriptomic patterns and ICI efficacy in malignant melanoma, lung and colorectal cancer. The immunomodulatory effect of the gut microbiome can have a real effect on the biological background of irAEs as well. Furthermore, specific microbial signatures and metabolites might be associated with the onset and severity of toxicity symptoms. By identifying these biological factors, novel biomarkers can be used in clinical practice to predict and manage potential irAEs. This comprehensive review aims to summarize the clinical aspects and biological background of ICI-related irAEs and their potential association with the gut microbiome and metabolome. We aim to explore the current state of knowledge on the most important and reliable irAE-related biomarkers of microbial origin and discuss the intriguing connection between ICI efficacy and toxicity.

2: A Novel Potent Platinum(IV) Prodrug Enhances Chemo-Immunotherapy by Facilitating PD-L1 Degradation in the Cytoplasm and Cytomembrane

Platinum drugs as primary chemotherapy drugs have been applied to various cancer patients. However, their therapeutic applicability is limited due to the adverse effects and immunosuppression. To minimize the side effects and boost the immune response, we designed and synthesized platinum(IV) prodrugs that introduced BRD4 inhibitor JQ-1. Among them, CJ2 had the most potent therapeutic activity and less toxicity. With the introduction of ligand JQ-1, CJ2-reduced PD-L1 protein was found in the cytoplasm and cytomembrane for the first time. By interfering with the PD-L1 synthesis, CJ2 could arouse the immune system and promote CD8+ T cell infiltration. Meanwhile, CJ2 could accelerate PD-L1 degradation in the cytoplasm to block DNA damage repair. In vivo, CJ2 markedly suppressed tumor growth by reversing the immunosuppression microenvironment and enhancing DNA damage. These findings provide an effective approach to improve the selectivity and activity of the platinum drugs with elevated immune response.

Characteristics and usefulness of transabdominal ultrasonography in immune-mediated colitis

BACKGROUND/AIMS

The usefulness of ultrasonography (US) in diseases of the gastrointestinal tract has been reported recently. This prospective study aimed to determine the features of US findings in immune-mediated colitis (IMC), an adverse event induced by immune checkpoint inhibitor, and examine the correlation between US findings, colonoscopy (CS) findings, and severity of colitis.

METHODS

We studied patients examined using CS and US upon suspicion of IMC in Hokkaido University Hospital between April 2018 and February 2021. Endoscopic findings of IMC were assessed using the Ulcerative Colitis Endoscopic Index of Severity (UCEIS). The severity of US findings in IMC was evaluated using US grade, which is the ultrasonographic grading scale in ulcerative colitis. Bowel wall thickness and the intensity of the color Doppler signal were also analyzed. Severity of colitis was evaluated using Common Terminology Criteria for Adverse Events (CTCAE) grade version 5.

RESULTS

Fourteen patients with IMC were enrolled. The US findings were bowel wall thickening, loss of stratification, ulceration and increased blood flow signal. The US grade was moderately correlated with the UCEIS (r=0.687, p=0.009) and CTCAE grade (r=0.628, p=0.035). Bowel wall thickness and UCEIS (r=0.628, p=0.020), as well as color Doppler signal grade and CTCAE grade (r=0.724, p=0.008), were significantly correlated.

CONCLUSIONS

US findings in IMC were mainly similar to those of ulcerative colitis, but there were some findings that were characteristic only of IMC. Significant correlation was found between US findings, CS findings, and severity of colitis. Hence, US could be useful for the evaluation of IMC.

Gastrointestinal injury induced by immunomodulators: A review article

An increasing number of immunomodulators, either anti-inflammatory or immunity-enhancing, have brought about a revolutionary effect in the management of a variety of autoimmune disorders and malignancies. However, their ability to cause gastrointestinal (GI) injury and induce GI symptoms has been increasingly and unexpectedly recognized. GI injury associated with immunomodulators may demonstrate various histologic and endoscopic patterns. Optimal diagnosis and treatment require a multidisciplinary approach. This review aims to provide an overview of the literature on its pathogenesis, the clinical, endoscopic, and histologic features, and suggested approaches to manage these newly recognized immunomodulator-induced GI adverse effects (AEs). We also reviewed current biomarkers predictive of GI toxicity and potential risk factors to identify susceptible patients. In addition, these immune-mediated AEs were compared with inflammatory bowel disease, a well-documented form of inflammation-driven GI injury. We hope this review will raise awareness and vigilance among clinicians of these entities to increase early diagnosis and rapid referral to specialist care.