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

Pathogenic Mechanisms of Immune Checkpoint Inhibitor (ICI)-Associated Retinal and Choroidal Adverse Reactions

PURPOSE

To summarize and categorize postulated mechanisms of immune checkpoint inhibitor (ICI)-mediated retinal and choroidal inflammation and discuss resulting implications for evaluation and management of these adverse reactions.

DESIGN

Targeted literature review with interpretation and perspective METHODS: We performed a review of selected literature describing immune-mediated retinal and choroidal adverse reactions associated with ICI therapy, synthesizing and categorizing the likely underlying pathogenic mechanisms. Based on these mechanistic categories, we provide perspective on a rational approach to the evaluation of patients with ICI-associated inflammatory disorders of the retina and choroid.

RESULTS

ICI-induced posterior segment adverse reactions can be categorized into 3 major mechanisms of unintended, targeted inflammation that share similarities to immunotherapy-related adverse events (irAEs) seen in other organ systems. In Type 1 reactions, T cell activation by ICIs can result in cross-reactivity of anti-tumor T cells with ocular tissues (Type 1a) or expansion of eye-specific T cells in predisposed individuals (Type 1b), leading to ocular inflammation that mimics known uveitic conditions. In Type 2 reactions, nonspecific ocular or systemic inflammation exacerbated by ICI use can cause retinal vasculitis through a "bystander" mechanism, potentially resulting in vision-threatening vascular occlusions. Finally, in Type 3 reactions, ICI use can prompt autoantibody-mediated inflammation and/or exacerbation of paraneoplastic processes likely related to T cell driven expansion of B cell populations.

CONCLUSIONS

Although relatively uncommon, posterior segment inflammatory disorders associated with systemic ICI therapy may be vision-threatening if not identified and treated appropriately. We propose that the pathogenic mechanisms underlying these chorioretinopathies falls into 3 major categories involving inadvertent T cell mediated inflammation. Visual prognosis with appropriate treatment is generally favorable, but some reactions, such as longstanding exudative retinal detachments and ICI-induced occlusive retinal vasculitis, can result in permanent visual defects.

Prediction, prevention, and precision treatment of immune checkpoint inhibitor neurological toxicity using autoantibodies, cytokines, and microbiota

Cancer immunotherapy with immune checkpoint inhibitors (ICIs) has revolutionized oncology, significantly improving survival across multiple cancer types. ICIs, such as anti-PD-1 (e.g. nivolumab, pembrolizumab), anti-PD-L1 (e.g. atezolizumab, avelumab), and anti-CTLA-4 (e.g. ipilimumab), enhance T cell-mediated anti-tumor responses but can also trigger immune-related adverse events (irAEs). Neurological irAEs (n-irAEs), affecting 1-3% of patients, predominantly involve the peripheral nervous system; less commonly, n-irAEs can present as central nervous system disorders. Although irAEs suggest a possible correlation with treatment efficacy, their mechanisms remain unclear, with hypotheses ranging from antigen mimicry to cytokine dysregulation and microbiome alterations. Identifying patients at risk for n-irAEs and predicting their outcome through biomarkers would be highly desirable. For example, patients with high-risk onconeural antibodies (such as anti-Hu or Ma2), and elevated neurofilament light chain (NfL) levels often respond poorly to irAE treatment. However, interpreting neuronal antibody tests in the diagnosis of n-irAEs requires caution: positive results must align with the clinical context, as some cancer patients (e.g., SCLC) may have asymptomatic low antibody levels, and false positive results are common without tissue-based confirmation. Also, the use of biomarkers (e.g. IL-6) may lead to more targeted treatments of irAEs, minimizing adverse effects without compromising the anti-tumor efficacy of ICIs. This review provides a comprehensive overview of the latest findings on n-irAEs associated with ICIs, with a focus on their prediction, prevention, as well as precision treatment using autoantibodies, cytokines, and microbiota. The most interesting data concern neuronal antibodies, which we explore in their pathogenic roles and as biomarkers of neurotoxicity. Most of the available data on cytokines, both regarding their role as diagnostic and prognostic biomarkers and their role in supporting therapeutic decisions for toxicities, refer to non-neurological toxicities. However, in our review, we mention the potential role of CXCL10 and CXCL13 as biomarkers of n-irAEs and describe the current evidence, as well as the need for further studies, on the use of cytokines in guiding selection of second-line therapies for n-irAEs. Finally, no specific microbiome-related microbial signature has been proven to be linked to n-irAEs specifically, leading to the need of more future research on the topic.

Predictors of severity and onset timing of immune-related adverse events in cancer patients receiving immune checkpoint inhibitors: a retrospective analysis

Objective

To identify predictors of all-grade, grade ≥ 3, and onset time of immune-related adverse events (irAEs) in cancer patients undergoing immune checkpoint inhibitors (ICIs) therapy.

Methods

This retrospective analysis included cancer patients treated with ICIs at Chongqing Medical University Second Affiliated Hospital from 2018 to 2024. Logistic regression and Cox regression analyses were used to identify predictors of all-grade and grade ≥ 3 irAEs and the time of irAE onset.

Results

Among the 3,795 patients analyzed, 1,101 (29.0%) developed all-grade irAEs, and 175 (4.6%) experienced grade ≥ 3 irAEs. Multivariate logistic regression revealed that female (OR = 1.37, p < 0.001), combination therapy (OR = 1.87, p < 0.001), pre-existing autoimmune diseases (AIDs) (OR = 5.15, p < 0.001), pre-existing cirrhosis (OR = 1.34, p = 0.001), antibiotic use during ICIs treatment (OR = 1.51, p < 0.001), and a higher baseline prognostic nutritional index (PNI) (OR = 1.23, p = 0.01) were significant predictors for the development of all-grade irAEs. The predictors for grade ≥ 3 irAEs included age ≥ 60 (OR = 1.49, p = 0.023) and pre-existing AIDs (OR = 2.09, p = 0.005), For the onset time, predictors included female (HR = 1.26, p = 0.001), combination therapy (HR = 1.80, p < 0.001), pre-existing AIDs (HR = 2.25, p < 0.001), and pre-existing infection (HR = 1.20, p = 0.008).

Conclusions

Females, combination therapy, pre-existing AIDs and cirrhosis, antibiotics, and a higher baseline PNI are associated with a higher risk of developing all-grade irAEs. Those aged ≥ 60 and with pre-existing AIDs face a higher risk of severe irAEs. Females, undergoing combination therapy, with pre-existing AIDs and infection generally experience a shorter time to irAEs onset. Multicentric prospective studies are warranted to validate these findings.

Causal relationship between gut microbiota and lung squamous cell carcinoma: a bidirectional two-sample Mendelian randomization study

PURPOSE

This study aims to explore the potential causal relationship between gut microbiota and lung squamous cell carcinoma (LUSC).

METHODS

A bidirectional two-sample Mendelian randomization analysis was conducted using genome-wide association study (GWAS) data from gut microbiota and LUSC. Gut microbiota served as the exposure factor, with instrumental variables selected from a GWAS involving 18 340 participants. LUSC data were drawn from a European cohort including 29 266 LUSC cases and 56 450 controls. Inverse-variance weighted (IVW) method was used as the primary method, with the Benjamini-Hochberg method applied to adjust for multiple comparisons. An independent dataset (ieu-a-967, containing 3275 LUSC cases and 15 038 controls) was used for replication analysis to ensure robustness.

RESULTS

IVW analysis found that Butyricicoccus (OR = 0.79, 95% CI: 0.63-0.99, P = .042) and Coprobacter (OR = 0.85, 95% CI: 0.74-0.97, P = .018) were significantly protective against LUSC. In contrast, Victivallis (OR = 1.11, 95% CI: 1.00-1.23, P = .045) and Ruminococcus (OR = 1.28, 95% CI: 1.03-1.60, P = .028) increased LUSC risk. Replication analysis in the independent dataset confirmed significant associations for Ruminococcus and Coprobacter. No reverse causality or pleiotropy was detected.

CONCLUSION

This study provides evidence of a causal relationship between specific gut microbiota and LUSC risk, highlighting new microbial targets for potential prevention and treatment strategies in lung cancer. Key messages What is already known on this topic?  Previous studies have suggested potential links between gut microbiota composition and the development of various cancers, including lung cancer. However, the exact causal relationship between specific gut microbiota and lung squamous cell carcinoma (LUSC) has remained unclear. Traditional observational studies have struggled to determine the direction of causality due to confounding factors, making further investigation necessary through more robust methods such as Mendelian randomization (MR). What this study adds?  This bidirectional MR study provides novel genetic evidence indicating that certain gut microbiotas are causally associated with LUSC risk. Specifically, Butyricicoccus appears to reduce the risk of LUSC, while Victivallis increases the risk. These findings highlight the role of the gut-lung axis in LUSC and open up new avenues for exploring gut microbiota as potential modulators of lung cancer risk. How this study might affect research, practice, or policy?  The implications of this study may significantly influence future research into cancer prevention strategies by targeting gut microbiota. Additionally, it could inform clinical practices aimed at modulating gut microbiota to lower the risk of LUSC, potentially influencing dietary or probiotic interventions to reduce cancer susceptibility. Furthermore, these results might shape public health policies that focus on the gut-lung axis as a novel avenue for cancer prevention and management.

Lactobacillus reuteri Assists Engineered Bacteria That Target Tumors to Release PD-L1nb to Mitigate the Adverse Effects of Breast Cancer Immunotherapy

Programmed death protein-ligand 1 (PD-L1) inhibitors demonstrate significant antitumor efficacy by modulating T-cell activity and inhibiting the PD-1/PD-L1 pathway, thus enhancing immune responses. Despite their robust effects, systemic administration of these inhibitors is linked to severe immune toxicity. To address this issue, we engineered a strain, REP, which releases PD-L1 nanoantibodies (PD-L1nb) to treat breast cancer and attenuate immunotherapy-related side effects. REP selectively targets tumors and periodically releases PD-L1nb within tumors via a quorum-sensing lysis system. Administration of 108 colony-forming units (CFU) of REP led to a substantial 52% reduction in tumor growth, achieved through the sustained release of PD-L1nb. Importantly, there were no detectable lesions in other organs, with the exception of mild intestinal damage. Further, we explored the potential of a combined treatment using Lactobacillus reuteri (LR) and REP to alleviate intestinal inflammation. LR modulates the expression of inflammatory markers IL-1β, IL-6, and IL-10 through the JNK pathway, reducing intestinal inflammation without compromising REP's antitumor efficacy. Consequently, we formulated a dual strategy employing an engineered strain and probiotics to reduce the adverse effects of immunotherapy in cancer treatment.

Metabolic pathways from the gut metatranscriptome are associated with COPD and respiratory function in lung cancer patients

Introduction

Changes in the human gut microbiome have been linked to various chronic diseases, including chronic obstructive pulmonary disease (COPD). While substantial knowledge is available on the genomic features of fecal communities, little is known about the microbiome's transcriptional activity. Here, we analyzed the metatranscriptomic (MTR) abundance of MetaCyc pathways, SuperPathways, and protein domain families (PFAM) represented by the gut microbiome in a cohort of non-small cell lung cancer (NSCLC) patients with- or without COPD comorbidity.

Methods

Fecal samples of 40 NSCLC patients with- or without COPD comorbidity were collected at the time of diagnosis. Data was preprocessed using the Metaphlan3/Humann3 pipeline and BioCyc© to identify metabolic SuperPathways. LEfSe analysis was conducted on Pathway- and PFAM abundance data to determine COPD- and non-COPD-related clusters.

Results

Key genera Streptococcus, Escherichia, Gemella, and Lactobacillus were significantly more active transcriptionally compared to their metagenomic presence. LEfSe analysis identified 11 MetaCyc pathways that were significantly overrepresented in patients with- and without COPD comorbidity. According to Spearman's rank correlation, Smoking PY showed a significant negative correlation with Glycolysis IV, Purine Ribonucleoside Degradation and Glycogen Biosynthesis I, and a significant positive correlation with Superpathway of Ac-CoA Biosynthesis and Glyoxylate cycle, whereas forced expiratory volume in the first second (FEV1) showed a significant negative correlation with Glycolysis IV and a significant positive correlation with Glycogen Biosynthesis I. Furthermore, COPD patients showed a significantly increased MTR abundance in ~60% of SuperPathways, indicating a universally increased MTR activity in this condition. FEV1 showed a significant correlation with SuperPathways Carbohydrate degradation, Glycan biosynthesis, and Glycolysis. Taxonomic analysis suggested a more prominent MTR activity from multiple Streptococcus species, Enterococcus (E.) faecalis, E. faecium and Escherichia (E.) coli than expected from their metagenomic abundance. Multiple protein domain families (PFAMs) were identified as more associated with COPD, E. faecium, E.coli, and Streptococcus salivarius, contributing the most to these PFAMs.

Conclusion

Metatranscriptome analysis identified COPD-related subsets of lung cancer with potential therapeutic relevance.

From bench to bedside: an interdisciplinary journey through the gut-lung axis with insights into lung cancer and immunotherapy

This comprehensive review undertakes a multidisciplinary exploration of the gut-lung axis, from the foundational aspects of anatomy, embryology, and histology, through the functional dynamics of pathophysiology, to implications for clinical science. The gut-lung axis, a bidirectional communication pathway, is central to understanding the interconnectedness of the gastrointestinal- and respiratory systems, both of which share embryological origins and engage in a continuous immunological crosstalk to maintain homeostasis and defend against external noxa. An essential component of this axis is the mucosa-associated lymphoid tissue system (MALT), which orchestrates immune responses across these distant sites. The review delves into the role of the gut microbiome in modulating these interactions, highlighting how microbial dysbiosis and increased gut permeability ("leaky gut") can precipitate systemic inflammation and exacerbate respiratory conditions. Moreover, we thoroughly present the implication of the axis in oncological practice, particularly in lung cancer development and response to cancer immunotherapies. Our work seeks not only to synthesize current knowledge across the spectrum of science related to the gut-lung axis but also to inspire future interdisciplinary research that bridges gaps between basic science and clinical application. Our ultimate goal was to underscore the importance of a holistic understanding of the gut-lung axis, advocating for an integrated approach to unravel its complexities in human health and disease.

Gut microbial metabolites in lung cancer development and immunotherapy: Novel insights into gut-lung axis

Metabolic derivatives of numerous microorganisms inhabiting the human gut can participate in regulating physiological activities and immune status of the lungs through the gut-lung axis. The current well-established microbial metabolites include short-chain fatty acids (SCFAs), tryptophan and its derivatives, polyamines (PAs), secondary bile acids (SBAs), etc. As the study continues to deepen, the critical function of microbial metabolites in the occurrence and treatment of lung cancer has gradually been revealed. Microbial derivates can enter the circulation system to modulate the immune microenvironment of lung cancer. Mechanistically, oncometabolites damage host DNA and promote the occurrence of lung cancer, while tumor-suppresive metabolites directly affect the immune system to combat the malignant properties of cancer cells and even show considerable application potential in improving the efficacy of lung cancer immunotherapy. Considering the crosstalk along the gut-lung axis, in-depth exploration of microbial metabolites in patients' feces or serum will provide novel guidance for lung cancer diagnosis and treatment selection strategies. In addition, targeted therapeutics on microbial metabolites are expected to overcome the bottleneck of lung cancer immunotherapy and alleviate adverse reactions, including fecal microbiota transplantation, microecological preparations, metabolite synthesis and drugs targeting metabolic pathways. In summary, this review provides novel insights and explanations on the intricate interplay between gut microbial metabolites and lung cancer development, and immunotherapy through the lens of the gut-lung axis, which further confirms the possible translational potential of the microbiome metabolome in lung cancer treatment.

Obesity, dysbiosis and inflammation: interactions that modulate the efficacy of immunotherapy

Recent years have seen an outstanding growth in the understanding of connections between diet-induced obesity, dysbiosis and alterations in the tumor microenvironment. Now we appreciate that gut dysbiosis can exert important effects in distant target tissues via specific microbes and metabolites. Multiple studies have examined how diet-induced obese state is associated with gut dysbiosis and how gut microbes direct various physiological processes that help maintain obese state in a bidirectional crosstalk. Another tightly linked factor is sustained low grade inflammation in tumor microenvironment that is modulated by both obese state and dysbiosis, and influences tumor growth as well as response to immunotherapy. Our review brings together these important aspects and explores their connections. In this review, we discuss how obese state modulates various components of the breast tumor microenvironment and gut microbiota to achieve sustained low-grade inflammation. We explore the crosstalk between different components of tumor microenvironment and microbes, and how they might modulate the response to immunotherapy. Discussing studies from multiple tumor types, we delve to find common microbial characteristics that may positively or negatively influence immunotherapy efficacy in breast cancer and may guide future studies.

Decoding the microbiota metabolome in hepatobiliary and pancreatic cancers: Pathways to precision diagnostics and targeted therapeutics

We delve into the critical role of the gut microbiota and its metabolites in the pathogenesis and progression of hepatobiliary and pancreatic (HBP) cancers, illuminating an urgent need for breakthroughs in diagnostic and therapeutic strategies. Given the high mortality rates associated with HBP cancers, which are attributed to aggressive recurrence, metastasis, and poor responses to chemotherapy, exploring microbiome research presents a promising frontier. This research highlights how microbial metabolites, including secondary bile acids, short-chain fatty acids, and lipopolysaccharides, crucially influence cancer cell behaviors such as proliferation, apoptosis, and immune evasion, significantly contributing to the oncogenesis and progression of HBP cancers. By integrating the latest findings, we discuss the association of microbial alterations with HBP cancers, key metabolites, and their implications, and how metabolomics and microbiomics can enhance diagnostic precision. Furthermore, the paper explores strategies for targeted therapies through microbiome metabolomics, including the direct therapeutic effects of microbiome metabolites and potential synergistic effects on conventional therapies. We also recognize that the field of microbial metabolites for the diagnosis and treatment of tumors still has a lot of problems to be solved. The aim of this study is to pioneer microbial metabolite research and provide a reference for HBP cancer diagnosis, treatment, and prognosis.

Plasma metabolomics of immune-related adverse events for patients with lung cancer treated with PD-1/PD-L1 inhibitors

BACKGROUND

Metabolomics has the characteristics of terminal effects and reflects the physiological state of biological diseases more directly. Several current biomarkers of multiple omics were revealed to be associated with immune-related adverse events (irAEs) occurrence. However, there is a lack of reliable metabolic biomarkers to predict irAEs. This study aims to explore the potential metabolic biomarkers to predict risk of irAEs and to investigate the association of plasma metabolites level with survival in patients with lung cancer receiving PD-1/PD-L1 inhibitor treatment.

METHODS

The study collected 170 plasmas of 85 patients with lung cancer who received immune checkpoint inhibitors (ICIs) treatment. 58 plasma samples of 29 patients with irAEs were collected before ICIs treatment and at the onset of irAEs. 112 plasma samples of 56 patients who did not develop irAEs were collected before ICIs treatment and plasma matched by treatment cycles to onset of irAEs patients. Untargeted metabolomics analysis was used to identify the differential metabolites before initiating ICIs treatment and during the process that development of irAEs. Kaplan-Meier curves analysis was used to detect the associations of plasma metabolites level with survival of patients with lung cancer.

RESULTS

A total of 24 differential metabolites were identified to predict the occurrence of irAEs. Baseline acylcarnitines and steroids levels are significantly higher in patients with irAEs, and the model of eight acylcarnitine and six steroid metabolites baseline level predicts irAEs occurrence with area under the curve of 0.91. Patients with lower concentration of baseline decenoylcarnitine(AcCa(10:1) 2, decenoylcarnitine(AcCa(10:1) 3 and hexanoylcarnitine(AcCa(6:0) in plasma would have better overall survival (OS). Moreover, 52 differential metabolites were identified related to irAEs during ICIs treatment, dehydroepiandrosterone sulfate, corticoserone, cortisol, thyroxine and sphinganine 1-phaosphate were significantly decreased in irAEs group while oxoglutaric acid and taurocholic acid were significantly increased in irAEs group.

CONCLUSIONS

High levels of acylcarnitines and steroid hormone metabolites might be risk factor to development of irAEs, and levels of decenoylcarnitine (AcCa(10:1) 2, decenoylcarnitine (AcCa(10:1) 3 and hexanoylcarnitine (AcCa(6:0) could be used to predict OS for patients with lung cancer received ICIs treatment.

Clinical Applications of the Gut Microbiome in Genitourinary Cancers

Recently recognized as one of the hallmarks of cancer, the microbiome consists of symbiotic microorganisms that play pivotal roles in carcinogenesis, the tumor microenvironment, and responses to therapy. With recent advances in microbiome metagenomic sequencing, a growing body of work has demonstrated that changes in gut microbiome composition are associated with differential responses to immune checkpoint inhibitors (ICIs) because of alterations in cytokine signaling and cytotoxic T-cell recruitment. Therefore, strategies to shape the gut microbiome into a more favorable, immunogenic profile may lead to improved responses with ICIs. Immunotherapy is commonly used in genitourinary (GU) cancers such as renal cell carcinoma, urothelial cancer, and to a limited extent, prostate cancer. However, a subset of patients do not derive clinical benefit with ICIs. Gut microbiome-based interventions are of particular interest given the potential to boost responses to ICIs in preclinical and early-phase prospective studies. Novel approaches using probiotic therapy (live bacterial supplementation) and fecal microbiota transplantation in patients with GU cancers are currently under investigation.

Modulating gut microbiome in cancer immunotherapy: Harnessing microbes to enhance treatment efficacy

Immunotherapy has emerged as a robust approach against cancer, yet its efficacy has varied among individuals, accompanied by the occurrence of immune-related adverse events. As a result, the efficacy of immunotherapy is far from satisfactory, and enormous efforts have been invested to develop strategies to improve patient outcomes. The gut microbiome is now well acknowledged for its critical role in immunotherapy, with better understanding on host-microbes interaction in the context of cancer treatment. Also, an increasing number of trials have been conducted to evaluate the potential and feasibility of microbiome-targeting approaches to enhance efficacy of cancer treatment in patients. Here, the role of the gut microbiome and metabolites (e.g., short-chain fatty acids, tryptophan metabolites) in immunotherapy and the underlying mechanisms are explored. The application of microbiome-targeting approaches that aim to improve immunotherapy efficacy (e.g., fecal microbiota transplantation, probiotics, dietary intervention) is also elaborated, with further discussion on current challenges and suggestions for future research.

Immune-related adverse events in non-small cell lung cancer: Occurrence, mechanisms and therapeutic strategies

The emergence of immune checkpoint inhibitors (ICIs) has heralded a transformative era in the therapeutic landscape of non-small cell lung cancer (NSCLC). While ICIs have demonstrated clinical efficacy in a portion of patients with NSCLC, these treatments concurrently precipitate a spectrum of immune-related adverse events (irAEs), encompassing mild to severe manifestations, collectively posing a risk of significant organ damage. Consequently, there exists an imperative to augment our comprehension of the pathophysiological underpinnings of irAEs and to formulate more efficacious preventive and ameliorative strategies. In this comprehensive review, we delineate the clinical presentation of organ-specific irAEs in patients with NSCLC and provide an in-depth analysis of recent advancements in understanding the mechanisms driving ICI-induced toxicity. Furthermore, we discuss potential strategies and targets for ameliorating these irAEs. Ultimately, this review aims to furnish valuable insights to guide further research endeavours in the context of irAEs in NSCLC patients.

Early Changes in LIPI Score Predict Immune-Related Adverse Events: A Propensity Score Matched Analysis in Advanced Non-Small Cell Lung Cancer Patients on Immune Checkpoint Blockade

In advanced cancer patients undergoing immune checkpoint blockade, the burden of immune-related adverse events (irAEs) is high. The need for reliable biomarkers for irAEs remains unfulfilled in this expanding therapeutic field. The lung immune prognostic index (LIPI) is a noninvasive measure of systemic inflammation that has consistently shown a correlation with survival in various cancer types when assessed at baseline. This study sought to determine whether early changes in the LIPI score could discriminate the risk of irAEs and different survival outcomes in advanced non-small cell lung cancer (NSCLC) patients receiving PD-(L)1 blockade-based therapies. We included consecutive patients diagnosed with metastatic NSCLC who received pembrolizumab, nivolumab, or atezolizumab as second-line therapy following platinum-based chemotherapy, or first-line pembrolizumab either alone or in combination with platinum-based chemotherapy. The LIPI score relied on the combined values of derived neutrophil/lymphocyte ratio (dNLR) and lactate dehydrogenase. Their assessment at baseline and after two cycles of treatment allowed us to categorize the population into three subgroups with good (LIPI-0), intermediate (LIPI-1), and poor (LIPI-2) prognosis. Between April 2016 and May 2023, we enrolled a total of 345 eligible patients, 165 (47.8%) and 180 (52.2%) of whom were treated as first- and second-line at our facility, respectively. After applying propensity score matching, we considered 83 relevant patients in each cohort with a homogeneous distribution of all characteristics across the baseline LIPI subgroups. There was a noticeable change in the distribution of LIPI categories due to a significant decrease in dNLR values during treatment. Although no patients shifted to a worse prognosis category, 20 (24.1%) transitioned from LIPI-1 to LIPI-0, and 7 (8.4%) moved from LIPI-2 to LIPI-1 (p < 0.001). Throughout a median observation period of 7.3 (IQR 3.9-15.1) months, a total of 158 irAEs (63.5%) were documented, with 121 (48.6%) and 39 (15.7%) patients experiencing mild to moderate and severe adverse events, respectively. Multivariate logistic regression analysis showed that the classification and changes in the LIPI score while on treatment were independent predictors of irAEs. The LIPI-0 group was found to have significantly increased odds of experiencing irAEs. Following a median follow-up period of 21.1 (95% CI 17.9-25.8) months, the multivariable Cox model confirmed LIPI categorization at any given time point as a significant covariate with influence on overall survival, irrespective of the treatment line. These findings suggest that reassessing the LIPI score after two cycles of treatment could help pinpoint patients particularly prone to immune-related toxicities. Those who maintain a good LIPI score or move from the intermediate to good category would be more likely to develop irAEs. The continuous assessment of LIPI provides prognostic insights and could be useful for predicting the benefit of PD-(L)1 checkpoint inhibitors.

The role of intestinal flora on tumorigenesis, progression, and the efficacy of PD-1/PD-L1 antibodies in colorectal cancer

Intestinal flora affects the maturation of the host immune system, serves as a biomarker and efficacy predictor in the immunotherapy of several cancers, and has an important role in the development of colorectal cancer (CRC). Anti-PD-1/PD-L1 antibodies have shown satisfactory results in MSI-H/dMMR CRC but performed poorly in patients with MSS/pMMR CRC. In recent years an increasing number of studies have shown that intestinal flora has an important impact on anti-PD-1/PD-L1 antibody efficacy in CRC patients. Preclinical and clinical evidence have suggested that anti-PD-1/PD-L1 antibody efficacy can be improved by altering the composition of the intestinal flora in CRC. Herein, we summarize the studies related to the influence of intestinal flora on anti-PD-1/PD-L1 antibody efficacy in CRC and discuss the potential underlying mechanism(s). We have focused on the impact of the intestinal flora on the efficacy and safety of anti-PD-1/PD-L1 antibodies in CRC and how to better utilize the intestinal flora as an adjuvant to improve the efficacy of anti-PD-1/PD-L1 antibodies. In addition, we have provided a basis for the potential of the intestinal flora as a new treatment modality and indicator for determining patient prognosis.

Mechanisms by which the intestinal microbiota affects gastrointestinal tumours and therapeutic effects

The intestinal microbiota is considered to be a forgotten organ in human health and disease. It maintains intestinal homeostasis through various complex mechanisms. A significant body of research has demonstrated notable differences in the gut microbiota of patients with gastrointestinal tumours compared to healthy individuals. Furthermore, the dysregulation of gut microbiota, metabolites produced by gut bacteria, and related signal pathways can partially explain the mechanisms underlying the occurrence and development of gastrointestinal tumours. Therefore, this article summarizes the latest research progress on the gut microbiota and gastrointestinal tumours. Firstly, we provide an overview of the composition and function of the intestinal microbiota and discuss the mechanisms by which the intestinal flora directly or indirectly affects the occurrence and development of gastrointestinal tumours by regulating the immune system, producing bacterial toxins, secreting metabolites. Secondly, we present a detailed analysis of the differences of intestinal microbiota and its pathogenic mechanisms in colorectal cancer, gastric cancer, hepatocellular carcinoma, etc. Lastly, in terms of treatment strategies, we discuss the effects of the intestinal microbiota on the efficacy and toxic side effects of chemotherapy and immunotherapy and address the role of probiotics, prebiotics, FMT and antibiotic in the treatment of gastrointestinal tumours. In summary, this article provides a comprehensive review of the pathogenic mechanisms of and treatment strategies pertaining to the intestinal microbiota in patients with gastrointestinal tumours. And provide a more comprehensive and precise scientific basis for the development of microbiota-based treatments for gastrointestinal tumours and the prevention of such tumours.

The association between aspirin use and immune-related adverse events in specific cancer patients receiving ICIs therapy: analysis of the FAERS database

Background: The promise of immune checkpoint inhibitors (ICIs) therapy in cancer treatment is tempered by the occurrence of immune-related adverse events (irAEs). Many patients undergoing ICIs also take aspirin, but the association between aspirin and irAEs is not well understood. Methods: This study analyzed adverse reaction data associated with the use of ICIs in the US Food and Drug Administration (FDA) Adverse Event Reporting System FDA Adverse Event Reporting System database, from the approval date of each drug until 1 October 2022. Multivariate logistic regression was employed to assess the association of aspirin use with irAEs in patients receiving ICIs. Results: The results indicated that aspirin use was associated with an increased risk of irAEs in a pan-cancer analysis, with a more pronounced association in specific cancer types such as lung cancer, mesothelioma, and pancreatic cancer. However, in lymphoma, aspirin use was associated with a reduced risk of irAEs. Furthermore, aspirin use was associated with an increased risk of certain irAEs, such as anemia, colitis, myocarditis, myositis, pancreatitis, pericarditis, and pneumonia, while it was associated with a reduced risk of rash, Stevens-Johnson syndrome, and thyroiditis. Conclusion: This study has unveiled an association between aspirin use and irAEs in cancer patients receiving ICIs therapy, emphasizing the need for individualized consideration of patients' medication history when devising cancer treatment plans to enhance efficacy and reduce risks.

Modulation of gut microbiota: a novel approach to enhancing the effects of immune checkpoint inhibitors

Although immune checkpoint inhibitors (ICIs) have greatly improved the prognosis of some cancer patients, the majority still fail to respond adequately, and the available biomarkers cannot reliably predict drug efficacy. The gut microbiota has received widespread attention among the various intrinsic and extrinsic factors contributing to drug resistance. As an essential regulator of physiological function, the impact of gut microbiota on host immunity and response to cancer therapy is increasingly recognized. Several studies have demonstrated significant differences in gut microbiota between responders and nonresponders. The gut microbiota associated with better clinical outcomes is called 'favorable gut microbiota'. Significantly, interventions can alter the gut microbiota. By shifting the gut microbiota to the 'favorable' one through various modifications, preclinical and clinical studies have yielded more pronounced responses and better clinical outcomes when combined with ICIs treatment, providing novel approaches to improve the efficacy of cancer immunotherapy. These findings may be attributed to the effects of gut microbiota and its metabolites on the immune microenvironment and the systemic immune system, but the underlying mechanisms remain to be discovered. In this review, we summarize the clinical evidence that the gut microbiota is strongly associated with the outcomes of ICI treatment and describe the gut microbiota characteristics associated with better clinical outcomes. We then expand on the current prevalent modalities of gut microbiota regulation, provide a comprehensive overview of preclinical and clinical research advances in improving the therapeutic efficacy and prognosis of ICIs by modulating gut microbiota, and suggest fundamental questions we need to address and potential directions for future research expansion.

Liquid Biopsy in Lung Cancer: Biomarkers for the Management of Recurrence and Metastasis

Liquid biopsies have emerged as a promising tool for the detection of metastases as well as local and regional recurrence in lung cancer. Liquid biopsy tests involve analyzing a patient's blood, urine, or other body fluids for the detection of biomarkers, including circulating tumor cells or tumor-derived DNA/RNA that have been shed into the bloodstream. Studies have shown that liquid biopsies can detect lung cancer metastases with high accuracy and sensitivity, even before they are visible on imaging scans. Such tests are valuable for early intervention and personalized treatment, aiming to improve patient outcomes. Liquid biopsies are also minimally invasive compared to traditional tissue biopsies, which require the removal of a sample of the tumor for further analysis. This makes liquid biopsies a more convenient and less risky option for patients, particularly those who are not good candidates for invasive procedures due to other medical conditions. While liquid biopsies for lung cancer metastases and relapse are still being developed and validated, they hold great promise for improving the detection and treatment of this deadly disease. Herein, we summarize available and novel approaches to liquid biopsy tests for lung cancer metastases and recurrence detection and describe their applications in clinical practice.