Bronchoalveolar lavage fluid reveals factors contributing to the efficacy of PD-1 blockade in lung cancer

Prognostic and predictive significance of soluble programmed death ligand 1 in bronchoalveolar lavage fluid in stage IV non-small cell lung cancer

Background

Patients with non-small cell lung cancer (NSCLC) have been shown to exhibit elevated levels of soluble programmed death-ligand 1 (sPD-L1) in the blood, associated with poor survival in NSCLC. The bronchoalveolar lavage fluid (BALF) composition reflects the tumor microenvironment of lung cancer. In this study, we investigated sPD-L1 levels in BALF and its role as a prognostic and predictive marker in patients with stage IV NSCLC.

Methods

We prospectively obtained BALF from lung cancer patients who underwent bronchoscopy between January 2020 and September 2022 at Chungnam National University Hospital (CNUH). Finally, 94 NSCLC stage IV patients were included in this study. Soluble PD-L1 levels in BALF were measured using a human PD-L1 Quantikine ELISA kit.

Results

The correlation between PD-L1 expression in tumor cells and sPD-L1 in BALF was weakly positive (rho =0.314, P=0.002). The median overall survival (OS) of the low sPD-L1 in BALF group was 16.47 months [95% confidence interval (CI): 11.15-21.79 months], which is significantly longer than 8.87 months (95% CI: 0.0-19.88 months, P=0.001) in the high sPD-L1 in BALF group. In 64 patients treated with or without immune checkpoint inhibitors (ICIs), sPD-L1 in BALF was significantly associated with progression-free survival (PFS) and OS. In the subgroup analysis of 31 patients treated with ICI, the objective response rate (ORR) in the low sPD-L1 BALF group was significantly higher than in high sPD-L1 in BALF group (ORR: 60.9% vs. 12.5%, P=0.02).

Conclusions

Soluble PD-L1 in BALF is a potential prognostic indicator for patients with stage IV NSCLC and a predictive marker for ICI treatment response.

Clinical significance of circulating biomarkers of immune-checkpoint molecules with atezolizumab plus bevacizumab therapy in unresectable hepatocellular carcinoma

BACKGROUND

The aims of this study were to identify clinically significant biomarkers of a response to atezolizumab plus bevacizumab (ATZ + BV) therapy and to develop target strategies against unresectable hepatocellular carcinoma (u-HCC).

METHOD

We first investigated the potential of circulating tumor DNA (ctDNA) to serve as a biomarker for predicting the therapeutic outcome in 24 u-HCC patients treated with ATZ + BV therapy. Next, we analyzed levels of immune-related cytokines in blood samples from 134 u-HCC patients who received ATZ + BV. For this, serum immune-related molecules or cancer-immune cycle-related molecules that have been reported in HCC patient sera, namely CD274, LAG-3, CCL2, 4, 5, CXCL1, 9, 10, 12, 13, CX3CL1, CCR5, IFNγ and IL-6, 8 were measured using enzyme-linked immunosorbent assay.

RESULTS

More than 1% of variant read frequency (VRF) mutations were found in TP53, APC, PIK3CA and VHL, although with no correlation with treatment response. Among the 15 cytokines evaluated, CXCL9 and LAG-3 levels were significantly different between patients with objective response (OR), stable disease (SD), and progressive disease (PD) following ATZ + BV treatment. Receiver-operating characteristic curve analyses of CXCL9 (cut-off value: 419.1 pg/ml) and LAG-3 (cut-off value: 3736.3 pg/ml) indicated areas of 0.779 and 0.697, respectively, for differentiating PD from non-PD and OR from non-OR. In multivariate analysis of progression-free survival (PFS) and overall survival (OS), high serum CXCL9 (hazard ratio (HR) and 95% confidence interval (CI): 0.412 (0.251-0.677) (p = 0.0005) for PFS and 0.252 (0.125-0.508) (p = 0.0001) for OS), and low serum LAG-3 (HR and 95% CI 0.419 (0.249-0.705) (p = 0.0011) for PFS and 0.294 (0.140-0.617) (p = 0.0012) for OS) were independent positive predictive factors.

CONCLUSION

Although, as far as we examined, no ctDNA mutations in blood were found to be related to ATZ + BV treatment efficacy, serum CXCL9 and LAG-3 levels, which are related to the cancer-immune cycle, were associated with treatment efficacy and could be predictive markers of the efficacy of ATZ + BV treatment in HCC patients.

Optimizing perioperative treatment for potentially resectable stage III squamous cell lung carcinoma: promising results of a condensed four-cycle regimen with tislelizumaband chemotherapy

BACKGROUND

The standard care for resectable non-small cell lung cancer (NSCLC) involves perioperative therapy combining chemotherapy and immune checkpoint inhibitors, typically lasting 6 to 12 months. However, the optimal treatment strategies for potentially resectable squamous cell lung carcinoma (SCC) remain unclear. This Phase 2 trial aimed to assess the efficacy and safety of a condensed four-cycle perioperative treatment regimen with tislelizumab combined with chemotherapy in patients with potentially resectable stage III SCC.

METHODS

Patients with potentially resectable stage IIIA-IIIB (N2) SCC received intravenous tislelizumab, albumin-bound paclitaxel, and carboplatin for up to four cycles. The primary endpoints were major pathologic response (MPR) and incidence of treatment-related adverse events. Safety and potential biomarkers for efficacy prediction were also assessed.

RESULTS

Among 35 enrolled patients, 32 underwent surgery with R0 resection achieved in all cases. MPR was achieved in 24 patients and pathological complete response (pCR) in 14 patients. Radiographic objective response was observed in 31 patients. The 12-month and 24-month event-free survival rate was 85.7 and 61.0%, respectively. Four patients experienced grade 3 or 4 adverse events. Tumor tissue based next-generation sequencing revealed the potential associations between several biomarkers and pathological response, including tumor neoantigen burden score, 18-gene expression profile score, CD8 + T cells, M1/M2 macrophages ratio and interferon-gamma expression level. Besides, circulating tumor DNA (ctDNA) dynamics and concentration were also associated with pathological response and the presence of ctDNA at postoperative month 1 was a strong predictor for disease relapse. Furthermore, metagenomic sequencing in bronchoalveolar lavage fluid demonstrated Streptococcus was the most abundant genus in the pCR group.

CONCLUSIONS

A condensed four-cycle perioperative treatment regimen of tislelizumab combined with chemotherapy demonstrated promising efficacy and manageable toxicities in potentially resectable stage III SCC. Specific biomarkers showed potential for predicting treatment efficacy and the mechanism of superior antitumor response of pCR patients was preliminarily and indirectly explored.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05024266. Registered August 27, 2021.

Evolving insights into the improvement of adoptive T-cell immunotherapy through PD-1/PD-L1 blockade in the clinical spectrum of lung cancer

Undeniably, cancer immunotherapies have expanded the spectrum of cancer treatment, however, some patients do not respond to immunotherapies. This scenario is no different for lung cancer, whose two main types, non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), still pose a serious clinical challenge. Adoptive T-cell therapies (ATC), which primarily include cytokine-induced killer (CIK) cell therapy, chimeric antigen receptor T-cell (CAR T-cell) therapy and γδ-T-cell therapy, strengthen the patient's immune system in combating cancer. Combining ATC with immune checkpoint inhibitors (ICI) further enhances the effectiveness of this approach to eradicate cancer. With a particular emphasis on CIK cell therapy, which recently completed 30 years, we highlight the role of the PD-1/PD-L1 axis in NSCLC and SCLC. Besides, we provide insights into the potential synergies of PD-1/PD-L1 inhibitors with adoptive T-cell immunotherapy in reshaping the treatment paradigm for lung cancer.

Symbiotic microbial communities in various locations of the lung cancer respiratory tract along with potential host immunological processes affected

Lung cancer has the highest mortality rate among all cancers worldwide. The 5-year overall survival rate for non-small cell lung cancer (NSCLC) is estimated at around 26%, whereas for small cell lung cancer (SCLC), the survival rate is only approximately 7%. This disease places a significant financial and psychological burden on individuals worldwide. The symbiotic microbiota in the human body has been significantly associated with the occurrence, progression, and prognosis of various diseases, such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis. Studies have demonstrated that respiratory symbiotic microorganisms and their metabolites play a crucial role in modulating immune function and contributing to the pathophysiology of lung cancer through their interactions with the host. In this review, we provide a comprehensive overview of the microbial characteristics associated with lung cancer, with a focus on the respiratory tract microbiota from different locations, including saliva, sputum, bronchoalveolar lavage fluid (BALF), bronchial brush samples, and tissue. We describe the respiratory tract microbiota's biodiversity characteristics by anatomical region, elucidating distinct pathological features, staging, metastasis, host chromosomal mutations, immune therapies, and the differentiated symbiotic microbiota under the influence of environmental factors. Our exploration investigates the intrinsic mechanisms linking the microbiota and its host. Furthermore, we have also provided a comprehensive review of the immune mechanisms by which microbiota are implicated in the development of lung cancer. Dysbiosis of the respiratory microbiota can promote or inhibit tumor progression through various mechanisms, including DNA damage and genomic instability, activation and regulation of the innate and adaptive immune systems, and stimulation of epithelial cells leading to the upregulation of carcinogenesis-related pathways.

Lung microbiome: new insights into the pathogenesis of respiratory diseases

The lungs were long thought to be sterile until technical advances uncovered the presence of the lung microbial community. The microbiome of healthy lungs is mainly derived from the upper respiratory tract (URT) microbiome but also has its own characteristic flora. The selection mechanisms in the lung, including clearance by coughing, pulmonary macrophages, the oscillation of respiratory cilia, and bacterial inhibition by alveolar surfactant, keep the microbiome transient and mobile, which is different from the microbiome in other organs. The pulmonary bacteriome has been intensively studied recently, but relatively little research has focused on the mycobiome and virome. This up-to-date review retrospectively summarizes the lung microbiome's history, composition, and function. We focus on the interaction of the lung microbiome with the oropharynx and gut microbiome and emphasize the role it plays in the innate and adaptive immune responses. More importantly, we focus on multiple respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), fibrosis, bronchiectasis, and pneumonia. The impact of the lung microbiome on coronavirus disease 2019 (COVID-19) and lung cancer has also been comprehensively studied. Furthermore, by summarizing the therapeutic potential of the lung microbiome in lung diseases and examining the shortcomings of the field, we propose an outlook of the direction of lung microbiome research.

Bronchoalveolar lavage fluid assessment facilitates precision medicine for lung cancer

Lung cancer is the most common and fatal malignant disease worldwide and has the highest mortality rate among tumor-related causes of death. Early diagnosis and precision medicine can significantly improve the survival rate and prognosis of lung cancer patients. At present, the clinical diagnosis of lung cancer is challenging due to a lack of effective non-invasive detection methods and biomarkers, and treatment is primarily hindered by drug resistance and high tumor heterogeneity. Liquid biopsy is a method for detecting circulating biomarkers in the blood and other body fluids containing genetic information from primary tumor tissues. Bronchoalveolar lavage fluid (BALF) is a potential liquid biopsy medium that is rich in a variety of bioactive substances and cell components. BALF contains information on the key characteristics of tumors, including the tumor subtype, gene mutation type, and tumor environment, thus BALF may be used as a diagnostic supplement to lung biopsy. In this review, the current research on BALF in the diagnosis, treatment, and prognosis of lung cancer is summarized. The advantages and disadvantages of different components of BALF, including cells, cell-free DNA, extracellular vesicles, and microRNA are introduced. In particular, the great potential of extracellular vesicles in precision diagnosis and detection of drug-resistant for lung cancer is highlighted. In addition, the performance of liquid biopsies with different body fluid sources in lung cancer detection are compared to facilitate more selective studies involving BALF, thereby promoting the application of BALF for precision medicine in lung cancer patients in the future.

May noninvasive mechanical ventilation and/ or continuous positive airway pressure increase the bronchoalveolar lavage salvage in patients with pulmonary diseases? Randomized clinical trial - Study protocol

PURPOSE

Bronchoalveolar lavage (BAL) procedure is a useful tool in the diagnosis of patients with interstitial lung disease (ILD) and is helpful in clinical research of chronic obstructive pulmonary disease (COPD) patients. Still little is known about predictors of poor BAL salvage. The trial aims to find the most efficient way to improve BAL recovery.

MATERIAL AND METHODS

Our study is a prospective, multicenter, international, two-arm randomized controlled trial. We aim to obtain BAL samples from a total number of 300 patients: 150 with ILD and 150 with COPD to achieve a statistical power of 80 ​%. Patients with initial BAL salvage <60 ​% will be randomized into the non-invasive ventilation (NIV) or continuous positive airway pressure (CPAP) arm. The NIV and CPAP will be set according to the study protocol. The influence on BAL salvage will be assessed in terms of BAL volume and content. Multivariable analysis of the additional test results to determine predictors for low BAL recovery will be conducted. In a study subgroup of approximately 20 patients per specific disease, a metabolomic assessment of exhaled air condensate will be performed. All procedures will be assessed in terms of the patient's safety. The trial was registered on clinicaltrials.gov (ID# NCT05631132). Interested experienced centers are invited to join the research group by writing to the corresponding author.

CONCLUSION

The results of our prospective study will address the currently unsolved problem of how to increase BAL salvage in patients with pulmonary diseases without increasing the risk of respiratory failure exacerbation.

Multi-dimensional characterization of immunological profiles in small cell lung cancer uncovers clinically relevant immune subtypes with distinct prognoses and therapeutic vulnerabilities

Small-cell lung cancer (SCLC) is generally considered a 'homogenous' disease, with little documented inter-tumor heterogeneity in treatment guidance or prognosis evaluation. The precise identification of clinically relevant molecular subtypes remains incomplete and their translation into clinical practice is limited. In this retrospective cohort study, we comprehensively characterized the immune microenvironment in SCLC by integrating transcriptional and protein profiling of formalin-fixation-and-paraffin-embedded (FFPE) samples from 29 patients. We identified two distinct disease subtypes: immune-enriched (IE-subtype) and immune-deprived (ID-subtype), displaying heterogeneity in immunological, biological, and clinical features. The IE-subtype was characterized by abundant immune infiltrate and elevated levels of interferon-alpha/gamma (IFNα/IFNγ) and inflammatory response, while the ID-subtype featured a complete lack of immune infiltration and a more proliferative phenotype. These two immune subtypes are associated with clinical benefits in SCLC patients treated with adjuvant therapy, with the IE-subtype exhibiting a more favorable response leading to improved survival and reduced disease recurrence risk. Additionally, we identified and validated a personalized prognosticator of immunophenotyping, the CCL5/CXCL9 chemokine index (CCI), using machine learning. The CCI demonstrated superior predictive abilities for prognosis and clinical benefits in SCLC patients, validated in our institute immunohistochemistry cohort and multicenter bulk transcriptomic data cohorts. In conclusion, our study provides a comprehensive and multi-dimensional characterization of the immune architecture of SCLC using clinical FFPE samples and proposes a new immune subtyping conceptual framework enabling risk stratification and the appropriate selection of individualized therapy.

Biomarkers for Immune Checkpoint Inhibitor Response in NSCLC: Current Developments and Applicability

Lung cancer has the highest mortality rate among all cancer types, resulting in over 1.8 million deaths annually. Immunotherapy utilizing immune checkpoint inhibitors (ICIs) has revolutionized the treatment of non-small cell lung cancer (NSCLC). ICIs, predominantly monoclonal antibodies, modulate co-stimulatory and co-inhibitory signals crucial for maintaining immune tolerance. Despite significant therapeutic advancements in NSCLC, patients still face challenges such as disease progression, recurrence, and high mortality rates. Therefore, there is a need for predictive biomarkers that can guide lung cancer treatment strategies. Currently, programmed death-ligand 1 (PD-L1) expression is the only established biomarker for predicting ICI response. However, its accuracy and robustness are not consistently reliable. This review provides an overview of potential biomarkers currently under development or in the validation stage that hold promise in improving the classification of responders and non-responders to ICI therapy in the near future.

PD-1/PD-L1 axis in organ fibrosis

Fibrosis is a pathological tissue repair activity in which many myofibroblasts are activated and extracellular matrix are excessively accumulated, leading to the formation of permanent scars and finally organ failure. A variety of organs, including the lung, liver, kidney, heart, and skin, can undergo fibrosis under the stimulation of various exogenous or endogenous pathogenic factors. At present, the pathogenesis of fibrosis is still not fully elucidated, but it is known that the immune system plays a key role in the initiation and progression of fibrosis. Immune checkpoint molecules are key regulators to maintain immune tolerance and homeostasis, among which the programmed cell death protein 1/programmed death ligand 1 (PD-1/PD-L1) axis has attracted much attention. The exciting achievements of tumor immunotherapy targeting PD-1/PD-L1 provide new insights into its use as a therapeutic target for other diseases. In recent years, the role of PD-1/PD-L1 axis in fibrosis has been preliminarily explored, further confirming the close relationship among PD-1/PD-L1 signaling, immune regulation, and fibrosis. This review discusses the structure, expression, function, and regulatory mechanism of PD-1 and PD-L1, and summarizes the research progress of PD-1/PD-L1 signaling in fibrotic diseases.

The Lung Microbiome in Carcinogenesis and Immunotherapy Treatment

ABSTRACT

Lung cancer is the leading cause of cancer-related deaths. Over the past 10 years, significant advances in treatment modalities, including immune checkpoint inhibitor (ICI) blockade, have led to improved outcomes. Elucidating predicative biomarkers in responders and nonresponders to ICI will lead to development of therapeutic targets that could enhance ICI efficacy. Recently, the gut microbiome was identified as a predictive biomarker for ICI in patients with multiple cancer types. However, it is unclear how other host microbiomes influence tumorigenesis and response to ICI. Other groups have explored the lung microbiome as it relates to carcinogenesis and immunotherapy efficacy. In this review, we explore the role of the lung microbiome in health and disease. We also review the current state of lung microbiome research as it relates to tumorigenesis and treatments and provide potential insights into how the lung microbiome could improve outcomes in patients with cancer.

Microbial Biomarkers for Lung Cancer: Current Understandings and Limitations

As our "hidden organ", microbes widely co-exist at various sites on the human body. These microbes are collectively referred to as the microbiome. A considerable number of studies have already proven that the microbiome has significant impacts on human health and disease progression, including cancers. The recent discovery of cancer-specific microbiomes renders these cancer-associated microbes as potential biomarkers and therapeutic targets. While at low biomass levels, the lung microbiome still dramatically influences the initiation, progression and treatment of lung cancers. However, research on lung cancer-associated microbiomes is emerging, and most profiling studies are performed within three years. Unfortunately, there are substantial inconsistencies across these studies. Variations in microbial diversity were observed, and different microbial biomarkers for lung cancer have been proposed. In this review, we summarized the current findings of lung cancer microbiome studies and attempt to explain the potential reasons for the dissimilarities. Other than lung microbiomes, oral and airway microbiomes are highly related to lung microbiomes and are therefore included as well. In addition, several lung cancer-associated bacterial genera have been detected by different independent studies. These bacterial genera may not be perfect biomarkers, but they still serve as promising risk factors for lung cancers and show great prognostic value.

Bronchoalveolar Lavage Fluid-Isolated Biomarkers for the Diagnostic and Prognostic Assessment of Lung Cancer

Lung cancer is considered one of the most fatal malignant neoplasms because of its late detection. Detecting molecular markers in samples from routine bronchoscopy, including many liquid-based cytology procedures, such as bronchoalveolar lavage fluid (BALF), could serve as a favorable technique to enhance the efficiency of a lung cancer diagnosis. BALF analysis is a promising approach to evaluating the tumor progression microenvironment. BALF's cellular and non-cellular components dictate the inflammatory response in a cancer-proliferating microenvironment. Furthermore, it is an essential material for detecting clinically significant predictive and prognostic biomarkers that may aid in guiding treatment choices and evaluating therapy-induced toxicities in lung cancer. In the present article, we have reviewed recent literature about the utility of BALF analysis for detecting markers in different stages of tumor cell metabolism, employing either specific biomarker assays or broader omics approaches.