Role of antibiotic use, plasma citrulline and blood microbiome in advanced non-small cell lung cancer patients treated with nivolumab

Safety and efficacy of immune checkpoint inhibitors in non-small-cell lung cancer: focus on challenging populations

In recent years, immune-checkpoint inhibitors (ICIs) have represented one of the major breakthroughs in advanced non-small cell lung cancer treatment scenario. However, enrollment in registering clinical trials is usually restricted, since frail patients (i.e., elderly, individuals with poor performance status and/or active brain metastases), as well as patients with chronic infections or who take concurrent medications, such as steroids, are routinely excluded. Thus, safety and efficacy of ICIs for these subgroups have not been adequately assessed in clinical trials, although these populations often occur in clinical practice. We reviewed the available data regarding the use of ICIs in these 'special' populations, including a focus on the issues raised by the administration of immunotherapy in lung cancer patients infected with Sars-Cov-2.

New Insights Into the Cancer-Microbiome-Immune Axis: Decrypting a Decade of Discoveries

The past decade has witnessed groundbreaking advances in the field of microbiome research. An area where immense implications of the microbiome have been demonstrated is tumor biology. The microbiome affects tumor initiation and progression through direct effects on the tumor cells and indirectly through manipulation of the immune system. It can also determine response to cancer therapies and predict disease progression and survival. Modulation of the microbiome can be harnessed to potentiate the efficacy of immunotherapies and decrease their toxicity. In this review, we comprehensively dissect recent evidence regarding the interaction of the microbiome and anti-tumor immune machinery and outline the critical questions which need to be addressed as we further explore this dynamic colloquy.

Influence of Pelvic Intensity-Modulated Radiation Therapy With Concurrent Cisplatin-Based Chemotherapy of Cervical Cancer on the Vaginal Microbiome

Pelvic intensity-modulated radiation therapy (IMRT) combined with concurrent chemotherapy is an effective treatment for cervical cancer; however, radiation resistance impairs its clinical benefit. The vaginal microbiome plays an important but poorly understood role in cancer radiochemotherapy. In this study, we investigated the effects of treatment on the overall composition and alteration of the vaginal microbiome in patients receiving pelvic IMRT with concurrent cisplatin-based chemotherapy. We collected samples from twenty patients with cervical cancer and six healthy controls and performed 16S rRNA sequencing. Vaginal microbial composition analysis revealed significant differences between the two groups, but no significant differences between radiation treatment time points. However, the relative abundances of Gammaproteobacteria, Gemmatimonadetes, Gemmatimonadales, Pseudomonadales, Gemmatimonadaceae, Rikenellaceae, Acinetobacter, Desulfovibrio, Prevotella 9, Rikenellaceae RC9 gut group, Turicibacter, and the metagenome increased with time. The results encourage further study into the effects of the vaginal microbiome on cervical cancer treatment strategies, especially radiochemotherapy. Better understanding of these effects could inform new therapeutic approaches to enhance the efficacy of radiochemotherapy.

Effects of Antibiotic Use on Outcomes in Cancer Patients Treated Using Immune Checkpoint Inhibitors: A Systematic Review and Meta-Analysis

Antibiotic (ATB) use seems to negatively affect the outcomes of immune checkpoint inhibitors (ICIs). The aim of this review is to clarify whether ATB use influences the efficacy of ICI treatment in cancer patients. Databases of MEDLINE, Embase, and Cochrane Library were searched for reports published in English between January 2007 and December 2019. We included studies that compared the outcomes of ATB use and no-ATB use in cancer patients using ICIs. Two reviewers independently selected eligible studies and extracted the data. Meta-analysis was performed with pooling of unadjusted hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS), and with pooling of odds ratios (ORs) for objective response rate (ORR). Thirty-eight studies involving 8409 patients were finally included for qualitative or quantitative analyses. Cancer types included renal cell carcinoma, non-small cell lung cancer, urothelial carcinoma, melanoma, gastrointestinal cancer, and others. Meta-analyses revealed that ATB use was associated with poor OS [HR: 1.80, 95% confidence interval (CI): 1.44-2.26, P<0.001], PFS (HR: 1.55, 95% CI: 1.26-1.91, P<0.001) and ORR (OR: 0.63, 95% CI: 0.42-0.95, P=0.03). Subgroup analysis found that these relationships were not influenced by cancer type or ICI regimens, but were dependent on the timing of ATB use. Narrative results of multivariable analyses further confirmed the negative effects of ATB use on OS and PFS. In cancer patients using ICIs, pre-ATB use close to the start of ICI treatment (within 60 d) was detrimental to outcomes in terms of OS, PFS, and ORR.

Radical Hemithoracic Radiotherapy Induces Systemic Metabolomics Changes That Are Associated with the Clinical Outcome of Malignant Pleural Mesothelioma Patients

Simple Summary

Radical hemithoracic radiotherapy represents a promising new advance in the field of radiation oncology and encouraging results have been achieved in the treatment of malignant pleural mesothelioma patients. This study showed that this radiotherapy modality produces significant changes in serum metabolomics profile mainly affecting arginine and polyamine biosynthesis pathways. Interestingly, individual metabolomics alterations were found associated with the clinical overall survival outcome of the radiotherapy treatment. These results highlight metabolomics profile analysis as a powerful prognostic tool useful to better understand the mechanisms underlying the interpatients variability and to identify patients who may receive the best benefit from this specific radiotherapy treatment.

Abstract

Radical hemithoracic radiotherapy (RHRT) represents an advanced therapeutic option able to improve overall survival of malignant pleural mesothelioma patients. This study aims to investigate the systemic effects of this radiotherapy modality on the serum metabolome and their potential implications in determining the individual clinical outcome. Nineteen patients undergoing RHRT at the dose of 50 Gy in 25 fractions were enrolled. Serum targeted metabolomics profiles were investigated at baseline and the end of radiotherapy by liquid chromatography and tandem mass spectrometry. Univariate and multivariate OPLS-DA analyses were applied to study the serum metabolomics changes induced by RHRT while PLS regression analysis to evaluate the association between such changes and overall survival. RHRT was found to affect almost all investigated metabolites classes, in particular, the amino acids citrulline and taurine, the C14, C18:1 and C18:2 acyl-carnitines as well as the unsaturated long chain phosphatidylcholines PC ae 42:5, PC ae 44:5 and PC ae 44:6 were significantly decreased. The enrichment analysis showed arginine metabolism and the polyamine biosynthesis as the most perturbed pathways. Moreover, specific metabolic changes encompassing the amino acids and acyl-carnitines resulted in association with the clinical outcome accounting for about 60% of the interpatients overall survival variability. This study highlighted that RHRT can induce profound systemic metabolic effects some of which may have a significant prognostic value. The integration of metabolomics in the clinical assessment of the malignant pleural mesothelioma could be useful to better identify the patients who can achieve the best benefit from the RHRT treatment.

Infections and Immunotherapy in Lung Cancer: A Bad Relationship?

Infectious diseases represent a relevant issue in lung cancer patients. Bacterial and viral infections might influence the patients’ prognosis, both directly affecting the immune system and indirectly impairing the outcome of anticancer treatments, mainly immunotherapy. In this analysis, we aimed to review the current evidence in order to clarify the complex correlation between infections and lung cancer. In detail, we mainly explored the potential impact on immunotherapy outcome/safety of (1) bacterial infections, with a detailed focus on antibiotics; and (2) viral infections, discriminating among (a) human immune-deficiency virus (HIV), (b) hepatitis B/C virus (HBV-HCV), and (c) Sars-Cov-2. A series of studies suggested the prognostic impact of antibiotic therapy administration, timing, and exposure ratio in patients treated with immune checkpoint inhibitors, probably through an antibiotic-related microbiota dysbiosis. Although cancer patients with HIV, HBV, and HCV were usually excluded from clinical trials evaluating immunotherapy, some retrospective and prospective trials performed in these patient subgroups reported similar results compared to those described in not-infected patients, with a favorable safety profile. Moreover, patients with thoracic cancers are particularly at risk of COVID-19 severe outcomes and mortality. Few reports speculated about the prognostic implications of anticancer therapy, including immunotherapy, in lung cancer patients with concomitant Sars-Cov-2 infection, showing, to date, inconsistent results. The correlation between infectious diseases and immunotherapy remains to be further explored and clarified in the context of dedicated trials. In clinical practice, the accurate and prompt multidisciplinary management of lung cancer patients with infections should be encouraged in order to select the best treatment options for these patients, avoiding unexpected toxicities, while maintaining the anticancer effect.

Is the survival of patients treated with ipilimumab affected by antibiotics? An analysis of 1585 patients from the French National hospital discharge summary database (PMSI)

Background: The gut microbiota has a key role in the regulation of the immune system. Disruption of the gut microbiota’s composition by antibiotics might significantly affect the efficacy of immune checkpoint inhibitors. In a study of patients treated with ipilimumab, we sought to assess the relationship between overall survival and in-hospital antibiotic administration.

Methods: Patients having been treated with ipilimumab between January 2012 and November 2014 were selected from the French National Hospital Discharge Summary Database. Exposure to antibiotics was defined as the presence of a hospital stay with a documented systemic bacterial infection in the 2 months before or the month after initiation of the patient’s first ever course of ipilimumab. The primary outcome was overall survival.

Results: We studied 43,124 hospital stays involving 1585 patients from 97 centers. All patients had received ipilimumab monotherapy for advanced melanoma. Overall, 117 of the 1585 patients (7.4%) were documented as having received systemic antibiotic therapy in hospital during the defined exposure period. The median overall survival time was shorter in patients with infection (6.3 months, vs. 15.4 months in patients without an infection; hazard ratio (HR) = 1.88, 95% confidence interval [1.46; 2.43], p = 10⁻⁶). In a multivariate analysis adjusted for covariates, infection was still significantly associated with overall survival (HR = 1.68, [1.30; 2.18], p = 10⁻⁵).

Conclusions: In patients treated with ipilimumab for advanced melanoma, infection, and antibiotic administration in hospital at around the time of the patient’s first ever course of ipilimumab appears to be associated with significantly lower clinical benefit.

Antibiotic administration shortly before or after immunotherapy initiation is correlated with poor prognosis in solid cancer patients: An up-to-date systematic review and meta-analysis

OBJECTIVE

Immune checkpoint inhibitors (ICIs) have recently achieved inspiring performance in improving the prognosis of various solid tumors. Gut microbiome plays a crucial modulatory role in the efficacy of ICIs, which can be influenced by antibiotic (ATB) administration. In this meta-analysis, we aimed to clarify the correlations of ATB administration with the prognosis of solid cancer patients receiving ICI treatment.

METHOD

The eligible literatures were searched using PubMed, Cochrane Library, Web of Science, and Clinical trials.gov databases before 29 February 2020. The correlations of ATB administration with overall survival (OS) and progression-free survival (PFS) were determined using Hazard ratios (HRs) coupled with 95% confidence intervals (CIs).

RESULTS

A total of 33 studies enrolling 5565 solid cancer patients receiving ICI treatment were included in this meta-analysis. As a whole, ATB administration was significantly correlated worse OS (HR = 1.76, 95%CI = 1.41-2.19, P < 0.00001) and PFS (HR = 1.76, 95%CI = 1.47-2.12, P < 0.00001). This significant association was then observed in the subgroup analysis based on region (except for OS in Europe), sample size, age, therapeutic strategy and ICI type. The similar results were also found in subgroup analysis for lung, renal cell (except for OS) and other cancers (such as melanoma) but not for mixed cancers. In addition, the ICI efficacy was more likely to be diminished by ATB administration within a time frame from 60 days before to 60 days after ICI initiation.

CONCLUSION

ATBs should be used cautiously in solid cancer patients receiving ICIs. However, further validations are still essential due to existing publication bias.

Integration of Serum Metabolomics into Clinical Assessment to Improve Outcome Prediction of Metastatic Soft Tissue Sarcoma Patients Treated with Trabectedin

Soft tissue sarcomas (STS) are a group of rare and heterogeneous cancers with few diagnostic or prognostic biomarkers. This metabolomics study aimed to identify new serum prognostic biomarkers to improve the prediction of overall survival in patients with metastatic STS. The study enrolled 24 patients treated with the same trabectedin regimen. The baseline serum metabolomics profile, targeted to 68 metabolites encompassing amino acids and bile acids pathways, was quantified by liquid chromatography-tandem mass spectrometry. Correlations between individual metabolomics profiles and overall survival were examined and a risk model to predict survival was built by Cox multivariate regression. The median overall survival of the studied patients was 13.0 months (95% CI, 5.6–23.5). Among all the metabolites investigated, only citrulline and histidine correlated significantly with overall survival. The best Cox risk prediction model obtained integrating metabolomics and clinical data, included citrulline, hemoglobin and patients’ performance status score. It allowed to distinguish patients into a high-risk group with a low median overall survival of 2.1 months and a low- to moderate-risk group with a median overall survival of 19.1 months (p < 0.0001). The results of this metabolomics translation study indicate that citrulline, an amino acid belonging to the arginine metabolism, represents an important metabolic signature that may contribute to explain the high inter-patients overall survival variability of STS patients. The risk prediction model based on baseline serum citrulline, hemoglobin and performance status may represent a new prognostic tool for the early classification of patients with metastatic STS, according to their overall survival expectancy.

The canine gastrointestinal microbiota: early studies and research frontiers

The canine gut microbiota is a complex microbial population that is potentially related to metabolism, immunologic activity and gastrointestinal (GI) diseases. Early studies revealed that the canine gut microbiota was dynamic, and bacterial populations in the adjacent gut segments were similar, with anaerobes predominating. Metagenomics analysis revealed that nutrient contents in the diet modulated bacterial populations and metabolites in the canine gut. Further research revealed significant correlations between dietary factors and canine gut core microbiomes. Canine GI diseases are closely correlated with gut microbiota dysbiosis and metabolic disorders. Probiotic-related therapies can effectively treat canine GI diseases. Recent studies have revealed that the canine gut microbiota is similar to the human gut microbiota, and dietary factors affect both. Studying canine intestinal microorganisms enables clarifying changes in the canine intestinal bacteria under different conditions, simulating human diseases in dog models, and conducting in-depth studies of the interactions between intestinal bacteria and disease.

NSCLC Immunotherapy Efficacy and Antibiotic Use: A Systematic Review and Meta-Analysis

Immune checkpoint inhibitors (ICIs) have dramatically improved patient outcomes in a variety of tumor types, but with variable efficacy. Recent research has suggested that antibiotic-induced disruption of the microbiota may impact ICI efficacy. We performed a systematic review and meta-analysis of studies that assessed the impact of antibiotic use on the survival of patients diagnosed with NSCLC and treated with ICI. We systematically searched Medline, the Cochrane Library, and major oncology conferences proceedings. Eligible studies mentioned hazard ratio or Kaplan-Meier curves for progression-free survival (PFS) or overall survival (OS) based on antibiotic exposure before or during ICI treatment. We identified 23 eligible studies. The impact of antibiotics was then evaluated in 2208 patients for PFS and 5560 for OS. For both PFS and OS meta-analyses, the between-study heterogeneity was high (Higgins and Thompson I2 of 69% and 80%, respectively). The pooled hazard ratio was 1.47 (95% confidence interval [CI]: 1.13-1.90) for PFS and 1.69 (95% CI: 1.25-2.29) for OS revealing a significantly reduced survival in patients with NSCLC exposed to antibiotics. The median OS was reduced on average by 6.7 months (95% CI: 5.1-8.4) in the patients exposed to antibiotics. The effect seems to depend on the time window of exposure with stronger effects reported when the patients took antibiotics [-60 days; +60 days] around ICI initiation. In patients with NSCLC, the findings of the meta-analysis indicate that antibiotic use before or during treatment with ICI leads to a median OS decreased by more than 6 months. Specifically, exposure shortly before or after ICI initiation seems to be particularly detrimental, whereas antibiotic use later during disease course does not seem to alter survival. Because PFS and OS were difficult to compare between studies owing to heterogeneity and the multiple confounding factors identified, further studies are needed to strengthen the understanding of this phenomenon.

Survival of Patients Treated with Antibiotics and Immunotherapy for Cancer: A Systematic Review and Meta-Analysis

Antibiotics (ABs) are common medications used for treating infections. In cancer patients treated with immune checkpoint inhibitors (ICIs), concomitant exposure to ABs may impair the efficacy of ICIs and lead to a poorer outcome compared to AB non-users. We report here the results of a meta-analysis evaluating the effects of ABs on the outcome of patients with solid tumours treated with ICIs. PubMed, the Cochrane Library and Embase were searched from inception until September 2019 for observational or prospective studies reporting the prognoses of adult patients with cancer treated with ICIs and with or without ABs. Overall survival (OS) was the primary endpoint, and progression-free survival (PFS) was the secondary endpoint. The effect size was reported as hazard ratios (HRs) with a 95% confidence interval (CI) and an HR > 1 associated with a worse outcome in ABs users compared to AB non-users. Fifteen publications were retrieved for a total of 2363 patients. In the main analysis (n = 15 studies reporting data), OS was reduced in patients exposed to ABs before or during treatment with ICIs (HR = 2.07, 95%CI 1.51–2.84; p < 0.01). Similarly, PFS was inferior in AB users in n = 13 studies with data available (HR = 1.53, 95%CI 1.22–1.93; p < 0.01). In cancer patients treated with ICIs, AB use significantly reduced OS and PFS. Short duration/course of ABs may be considered in clinical situations in which they are strictly needed.

Molecular markers related to immunosurveillance as predictive and monitoring tools in non-small cell lung cancer: recent accomplishments and future promises

Introduction: The landscape of systemic treatment options for lung cancer has rapidly evolved with the emergence of immunomodulatory agents such as neutralizing antibodies targeting the programmed cell death protein 1 (PD-1) and its ligand (PD-L1). Another major breakthrough was the introduction of biomarkers, such as PD-L1 expression and tumor mutational burden (TMB), predicting response to immunotherapy. However, markers for monitoring treatment response are still lacking.Areas covered: PD-L1 and TMB represent static pre-treatment evaluations. Dynamic biomarkers are required, along with static ones, to accurately predict and monitor immunotherapy response and to discriminate between responders and non-responders early in the course of treatment. The tumor immune contexture offers potential candidates that can be tested through the liquid biopsy approach, such as circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), exosomes, microRNAs (miRNAs), circular RNAs (circRNAs), RNA splice variants, and immune cell subsets.Expert opinion: A holistic approach combining information from tissue at the time of diagnosis and serial liquid biopsy data could lead to a novel combinatorial biomarker panel with enhanced treatment monitoring potential. Incorporating information from additional parts of the tumor-host ecosystem, such as metabolic markers and the microbiome is expected to provide added value to this strategy.

Systemic therapies for intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is a highly lethal hepatobiliary neoplasm whose incidence is increasing. Largely neglected for decades as a rare malignancy and frequently misdiagnosed as carcinoma of unknown primary, considerable clinical and investigative attention has recently been focused on iCCA worldwide. The established standard of care includes first-line (gemcitabine and cisplatin), second-line (FOLFOX) and adjuvant (capecitabine) systemic chemotherapy. Compared to hepatocellular carcinoma, iCCA is genetically distinct with several targetable genetic aberrations identified to date. Indeed, FGFR2 and NTRK fusions, and IDH1 and BRAF targetable mutations have been comprehensively characterised and clinical data is emerging on targeting these oncogenic drivers pharmacologically. Also, the role of immunotherapy has been examined and is an area of intense investigation. Herein, in a timely and topical manner, we will review these advances and highlight future directions of research.

The effect of antibiotics on clinical outcomes in immune-checkpoint blockade: a systematic review and meta-analysis of observational studies

PURPOSE

Pre-clinical and early clinical data suggests the microbiome plays an important role in oncogenesis and influences response to immune checkpoint blockade (ICB). The objective of this systematic review and meta-analysis was to determine whether antibiotics affect overall survival (OS) and progression free survival (PFS) in patients with solid malignancies treated with ICB.

PATIENTS AND METHODS

A systematic search of EMBASE, MEDLINE and conference proceedings was conducted for observational studies examining the effect of antibiotics on ICB. A random effects study-level meta-analysis was performed with pooling of the hazards ratio (HR) for OS and PFS. Meta-regression was used to determine the impact of the timing of antibiotic exposure on OS.

RESULTS

766 studies were identified, and 18 studies met the inclusion criteria. Of the 2889 patients included, 826 (28.6%) were exposed to antibiotics. The most common malignancies were lung (59%), renal cell carcinoma (RCC) or urothelial carcinoma (16.3%) and melanoma (18.7%). OS was prolonged in those without antibiotic exposure (pooled HR 1.92, 95% CI 1.37-2.68, p < 0.001). The effect of antibiotics on OS was greater in studies defining antibiotic exposure as 42 days prior to initiation of ICB (HR 3.43, 95% CI 2.29-5.14, p < 0.0001). PFS was also longer in patients who did not receive antibiotics (pooled HR 1.65, 95% CI 1.3-2.1, p < 0.0001).

CONCLUSION

In patients receiving ICB, OS and PFS are longer in patients who are not exposed to antibiotics. Antibiotic use in the 42 days before starting ICB appears to be most detrimental to outcome.

Antibiotic therapy and outcome from immune-checkpoint inhibitors

Sensitivity to immune checkpoint inhibitor (ICPI) therapy is governed by a complex interplay of tumor and host-related determinants. Epidemiological studies have highlighted that exposure to antibiotic therapy influences the probability of response to ICPI and predict for shorter patient survival across malignancies. Whilst a number of studies have reproducibly documented the detrimental effect of broad-spectrum antibiotics, the immune-biologic mechanisms underlying the association with outcome are poorly understood. Perturbation of the gut microbiota, an increasingly well-characterized factor capable of influencing ICPI-mediated immune reconstitution, has been indicated as a putative mechanism to explain the adverse effects attributed to antibiotic exposure in the context of ICPI therapy. Prospective studies are required to validate antibiotic-mediated gut perturbations as a mechanism of ICPI refractoriness and guide the development of strategies to overcome this barrier to an effective delivery of anti-cancer immunotherapy.

Plasma Biomarkers and Immune Checkpoint Inhibitors in Non-Small Cell Lung Cancer: New Tools for Better Patient Selection?

Immune checkpoint inhibitors (ICIs) have transformed the treatment landscape for patients with non-small cell lung cancer (NSCLC). Although some patients can experience important response rates and improved survival, many others do not benefit from ICIs developing hyper-progressive disease or immune-related adverse events. This underlines the need to select biomarkers for ICIs use in order to better select patients. There is currently no universally validated robust biomarker for daily use of ICIs. Programmed death-ligand 1 (PD-L1) or tumor mutational burden (TMB) are sometimes used but still have several limitations. Plasma biomarkers are a promising approach in ICI treatment. This review will describe the development of novel plasma biomarkers such as soluble proteins, circulating tumor DNA (ctDNA), blood TMB, and blood microbiome in NSCLC patients treated with ICIs and their potential use in predicting response and toxicity.