CEA, SCC and NSE levels in exhaled breath condensate--possible markers for early detection of lung cancer

Recent advances in biosensors detecting biomarkers from exhaled breath and saliva for respiratory disease diagnosis

The global demand for rapid and non-invasive diagnostic methods for respiratory diseases has significantly intensified due to the wide spread of respiratory infectious diseases. Recent advancements in respiratory disease diagnosis through the analysis of exhaled breath and saliva has attracted great attention all over the world. Among various analytical methods, biosensors can offer non-invasive, efficient, and cost-effective diagnostic capabilities, emerging as promising tools in this area. This review intends to provide a comprehensive overview of various biosensors for the detection of respiratory disease related biomarkers in exhaled breath and saliva. Firstly, the characteristics of exhaled breath and saliva, including their generation, composition, and relevant biomarkers are introduced. Subsequently, the design and application of various biosensors for detecting these biomarkers are presented, along with the innovative materials employed as sensitive components. Different types of biosensors are reviewed, including electrochemical, optical, piezoelectric, semiconductor, and other novel biosensors. At last, the challenges, limitations, and future trends of these biosensors are discussed. It is anticipated that biosensors will play a significant role in respiratory disease diagnosis in the future.

The Role of Exhaled Breath Condensate in Chronic Inflammatory and Neoplastic Diseases of the Respiratory Tract

Asthma and chronic obstructive pulmonary disease (COPD) are among the most common chronic respiratory diseases. Chronic inflammation of the airways leads to an increased production of inflammatory markers by the effector cells of the respiratory tract and lung tissue. These biomarkers allow the assessment of physiological and pathological processes and responses to therapeutic interventions. Lung cancer, which is characterized by high mortality, is one of the most frequently diagnosed cancers worldwide. Current screening methods and tissue biopsies have limitations that highlight the need for rapid diagnosis, patient differentiation, and effective management and monitoring. One promising non-invasive diagnostic method for respiratory diseases is the assessment of exhaled breath condensate (EBC). EBC contains a mixture of volatile and non-volatile biomarkers such as cytokines, leukotrienes, oxidative stress markers, and molecular biomarkers, providing significant information about inflammatory and neoplastic states in the lungs. This article summarizes the research on the application and development of EBC assessment in diagnosing and monitoring respiratory diseases, focusing on asthma, COPD, and lung cancer. The process of collecting condensate, potential issues, and selected groups of markers for detailed disease assessment in the future are discussed. Further research may contribute to the development of more precise and personalized diagnostic and treatment methods.

Mapping the landscape of lung cancer breath analysis: A scoping review (ELCABA)

Lung cancer is the leading cause of cancer death worldwide due to its late-stage detection. Lung cancer screening, including low-dose computed tomography (low-dose CT), provides an initial clinical solution. Nevertheless, further innovations and refinements would help to alleviate remaining limitations. The non-invasive, gentle, and fast nature of breath analysis (BA) makes this technology highly attractive to supplement low-dose CT for an improved screening algorithm. However, BA has not taken hold in everyday clinical practice. One reason might be the heterogeneity and variety of BA methods. This scoping review is a comprehensive summary of study designs, breath analytical methods, and suggested biomarkers in lung cancer. Furthermore, this synthesis provides a framework with core outcomes for future studies in lung cancer BA. This work supports future research for evidence synthesis, meta-analysis, and translation into clinical routine workflows.

Exhaled metabolic markers and relevant dysregulated pathways of lung cancer: a pilot study

INTRODUCTION

The clinical application of lung cancer detection based on breath test is still challenging due to lack of predictive molecular markers in exhaled breath. This study explored potential lung cancer biomarkers and their related pathways using a typical process for metabolomics investigation.

MATERIAL AND METHODS

Breath samples from 60 lung cancer patients and 176 healthy people were analyzed by GC-MS. The original data were GC-MS peak intensity removing background signal. Differential metabolites were selected after univariate statistical analysis and multivariate statistical analysis based on OPLS-DA and Spearman rank correlation analysis. A multivariate PLS-DA model was established based on differential metabolites for pattern recognition. Subsequently, pathway enrichment analysis was performed on differential metabolites.

RESULTS

The discriminant capability was assessed by ROC curve of whom the average AUC and average accuracy in 100-fold cross validations were 0.871 and 0.787, respectively. Eight potential biomarkers were involved in a total of 18 metabolic pathways. Among them, 11 metabolic pathways have p-value smaller than .1.

DISCUSSION

Some pathways among them are related to risk factors or therapies of lung cancer. However, more of them are dysregulated pathways of lung cancer reported in studies based on genome or transcriptome data.

CONCLUSION

We believe that it opens the possibility of using metabolomics methods to analyze data of exhaled breath and promotes involvement of knowledge dataset to cover more volatile metabolites.

CLINICAL SIGNIFICANCE

Although a series of related research reported diagnostic models with highly sensitive and specific prediction, the clinical application of lung cancer detection based on breath test is still challenging due to disease heterogeneity and lack of predictive molecular markers in exhaled breath. This study may promote the clinical application of this technique which is suitable for large-scale screening thanks to its low-cost and non-invasiveness. As a result, the mortality of lung cancer may be decreased in future.Key messagesIn the present study, 11 pathways involving 8 potential biomarkers were discovered to be dysregulated pathways of lung cancer.We found that it is possible to apply metabolomics methods in analysis of data from breath test, which is meaningful to discover convinced volatile markers with definite pathological and histological significance.

Prognostic value of neuron specific enolase in patients with advanced and metastatic non-neuroendocrine non-small cell lung cancer

Background: Increased serum neuron-specific enolase (NSE) level was found in a substantial proportion (30–69%) of patients with non-small-cell lung cancer (NSCLC), but little was known about the clinical properties of NSE in NSCLC.

Objective: We aimed to assess the level of serum NSE to predict prognosis and treatment response in patients with advanced or metastatic non-neuroendocrine NSCLC.

Methods: We retrospectively analyzed 363 patients with advanced and metastatic NSCLC between January 2011 and October 2016. The serum NSE level was measured before initiation of treatment.

Results: Patients with high NSE level (≥26.1 ng/ml) showed significantly shorter progression-free survival (PFS) (5.69 vs 8.09 months; P=0.02) and significantly shorter overall survival (OS) than patients with low NSE level (11.41 vs 24.31 months; P=0.01).

NSE level was an independent prognostic factor for short PFS (univariate analysis, hazard ratio [HR] = 2.40 (1.71–3.38), P<0.001; multivariate analysis, [HR] = 1.81 (1.28–2.56), P=0.001) and OS (univariate analysis, [HR] = 2.40 (1.71–3.37), P<0.001; multivariate analysis, [HR] = 1.76 (1.24–2.50), P=0.002).

Conclusion: The survival of NSCLC patients with high serum NSE level was shorter than that of NSCLC patients with low serum NSE levels. Serum NSE level was a predictor of treatment response and an independent prognostic factor.

Exhaled breath biomarker sensing

This goal of this minireview is to introduce the reader to the area of research concerned with exhaled breath analysis for the purpose of detecting abnormal levels of physiologically-relevant chemical markers reflective of respiratory diseases. Two main two groups of sensing methods are reviewed: mass spectrometry and (bio)sensors. The discussion focuses on biosensor applications for EB and EBC analyses, which are presented in detail. The review finishes with conclusions and future perspectives, including recommendations for future near-term and long-term development of EBC biomarker sensing.

Biosensing Near the Exceptional Point Based on Resonant Optical Tunneling Effect

Inspired by exceptional point (EP) sensing in non-Hermitian systems, in this work, a label-free biosensor for detecting low-concentration analytes is proposed, via a special multilayer structure: a resonant optical tunneling resonator. Due to the square root topology near the exceptional point, a recognized target analyte perturbs the system deviated from the exceptional point, leading to resolvable modes splitting in the transmission spectrum. The performance of the designed sensor is analyzed by the coupled-mode theory and transfer matrix method, separately. Here, the simulation results demonstrate that the obtained sensitivity is 17,120 nm/imaginary part unit of refractive index (IP) and the theoretical detection limit is 4.2 × 10^-8 IP (regarding carcinoembryonic antigen (CEA), the minimum detection value is 1.78 ng). Instead of the typical diffusion manner, the liquid sample is loaded by convection, which can considerably improve the efficiency of sample capture and shorten the response time of the sensor. The sketched sensor may find potential application in the fields of biomedical detection, environment protection, and drinking water safety.

Epidemiology and prognosis in young lung cancer patients aged under 45 years old in northern China

To explore the epidemiological characteristics and prognosis of lung cancer in patients aged under 45 years old in northern China. The population-based database about lung cancer cases aged under 45y selected form the Hebei Provincial Cancer Registry Center from 2010-2015. Mortality data of young death from 1973 to 1975, 1990 to 1992, and 2004 to 2005 were extracted from the national retrospective survey of death. Mortality rates were calculated by the mortality database above in this analysis. Consecutive, 954 non-selected younger patients (< 45 years) and 2261 selected older patients (≥ 45 years) with pathologically diagnosed lung cancer treated at the Fourth Hospital of Hebei Medical University were included as the hospital-based database. Epidemiological, treatment outcomes and prognosis status from 2010 to 2017 were documented. A comparison with younger and older patients was also made. Multivariate analysis with young lung cancer patients was calculated by Cox regression model. The younger lung cancer mortality rate tended to slightly increase in Hebei Province, from 1.04 per100 000 in 1973 to 2.01 per 100 000 in 2015, but the PDR tended to decrease over the last 40 years. There were 954 younger and 2261 older lung cancer patients included in the hospital-based database. The proportions of patients who were female (50.84% vs 34.85%), family history of cancer (12.37% vs 6.32%), advanced stage at diagnosis (65.46% vs 60.77%) and adenocarcinoma (65.27% vs 61.11%) were relatively higher in the younger group than in the older group. The median OS were 23.0 months and 27.0 months between younger and older, the OS difference existed between the two groups (P = 0.001). In the younger patients, Cox regression showed that a family history of cancer, symptoms at diagnosis, pathology, stage at diagnosis and surgery were confirmed as independent factors affecting the prognosis. Mortality rates among younger lung cancer patients showed an increasing trend in northern China. The younger account for small but have unique characteristics, with higher proportions of female, family history of cancer, adenocarcinoma and advanced stages than the older group and had a trend of worse OS.

Breath profile as composite biomarkers for lung cancer diagnosis

OBJECTIVES

Lung cancer is continuously the leading cause of cancer related death, resulting from the lack of specific symptoms at early stage. A large-scale screening method may be the key point to find asymptomatic patients, leading to the reduction of mortality.

METHODS

An alternative method combining breath test and a machine learning algorithm is proposed. 236 breath samples were analyzed by TD-GCMS. Breath profile of each sample is composed of 308 features extracted from chromatogram. Gradient boost decision trees algorithm was employed to recognize lung cancer patients. Bootstrap is performed to simulate real diagnostic practice, with which we evaluated the confidence of our methods.

RESULTS

An accuracy of 85 % is shown in 6-fold cross validations. In statistical bootstrap, 72 % samples are marked as "confident", and the accuracy of confident samples is 93 % throughout the cross validations.

CONCLUSION

We have proposed such a non-invasive, accurate and confident method that might contribute to large-scale screening of lung cancer. As a consequence, more asymptomatic patients with early lung cancer may be detected.

Love wave based portable sensing system for on-line detection of carcinoembryonic antigen in exhaled breath condensate

Lung cancer is continuously the leading cause of cancer related death. Noninvasive exhaled breath condensate (EBC) detection using portable devices may pave a new avenue for monitoring conditions of the high-risk population of lung cancer, thereby increasing the 5-year survival rate. Here, a portable system is proposed for on-line detection of carcinoembryonic antigen (CEA) in EBC. This miniaturized system employs an aptameric Love-wave sensor to provide a detection with advantages of low cost, operational simplicity and high sensitivity. In addition, the aptasensor can be used in label-free and real-time monitoring. Integrating with measurement circuits and iOS APP, the system realizes online transmission and processing of signals which reflect the CEA concentration. Artificial samples have been detected, and experimental results demonstrate that the present system is sensitive (limit of detection = 1 ng/ml) and accurate (relative accuracy = 0.995). Applying in detection of clinical EBC, the relative error is as low as 0.305% and the result can be used to distinguish lung cancer patients from healthy subjects. Therefore, this portable system offers a potential solution for noninvasive detection of lung cancer in its early stage.

Surface-enhanced electrochemiluminescence combined with resonance energy transfer for sensitive carcinoembryonic antigen detection in exhaled breath condensates

The detection of biomarkers in exhaled breath condensates (EBCs) is regarded as a promising non-invasive diagnostic approach. However, the ultralow concentration of biomarkers in EBCs is a great challenge. Herein, a sensitive dual signal amplification strategy was developed based on surface-enhanced electrochemiluminescence (SEECL) combined with resonance energy transfer (RET). Gold nanoparticles-functionalized graphite-like carbon nitride nanohybrids (Au-g-C₃N₄ NHs) could be used as an energy transfer donor because of the good overlap between its emission peak and the absorption peak of tris(2,2'-bipyridine)ruthenium dichloride (Ru(bpy)₃Cl₂) at 460 nm. Gold-silicon dioxide core-shell nanoparticles doped with Ru(bpy)₃²⁺(Au@SiO₂-Ru) were employed as an energy transfer acceptor emitting at 620 nm. Moreover, the signals at 620 nm emitted by Ru (bpy)₃²⁺ were enhanced by 5 times, attributed to the localized surface plasmon resonance (LSPR) of gold nanoparticles (Au NPs). The detection of carcinoembryonic antigen (CEA) was performed by using two aptamers as the recognition unit; whereby aptamer 1 (Apt1) was modified on the surface of Au-g-C₃N₄ NHs, and aptamer 2 (Apt2) was banded on the surface of Au@SiO₂-Ru. In the presence of CEA, a sandwich structure was formed between Au-g-C₃N₄ NHs-Apt1-CEA and Apt2-Au@SiO₂-Ru, which resulted in an ultrasensitive detection of CEA. The proposed electrochemiluminescence sensor showed a wide linear relationship with the CEA concentration in the range from 1.0 pg mL^-1 to 5.0 ng mL^-1, with a limit of detection (LOD) of 0.3 pg mL^-1. Finally, the practicality of the proposed sensor was demonstrated to detect CEA in EBCs, and the obtained results were in good agreement with the enzyme-linked immunosorbent assay (ELISA) method.

Multifunctional neuron-specific enolase: its role in lung diseases

Neuron-specific enolase (NSE), also known as gamma (γ) enolase or enolase-2 (Eno2), is a form of glycolytic enolase isozyme and is considered a multifunctional protein. NSE is mainly expressed in the cytoplasm of neurons and neuroendocrine cells, especially in those of the amine precursor uptake and decarboxylation (APUD) lineage such as pituitary, thyroid, pancreas, intestine and lung. In addition to its well-established glycolysis function in the cytoplasm, changes in cell localization and differential expression of NSE are also associated with several pathologies such as infection, inflammation, autoimmune diseases and cancer. This article mainly discusses the role and diagnostic potential of NSE in some lung diseases.

Exhaled Breath Condensate: A Non-Invasive Source for Tracking of Genetic and Epigenetic Alterations in Lung Diseases

Lung diseases have been recognized as an extensive cause of morbidity and mortality in the worldwide. The high degree of clinical heterogeneity and nonspecific initial symptoms of lung diseases contribute to a delayed diagnosis. So, the molecular and genomic profiling play a pivotal role in promoting the pulmonary diseases. Exhaled breath condensate (EBC) as a novel and potential method for sampling the respiratory epithelial lining fluid is to assess the inflammatory and oxidative stress biomarkers, drugs and genetic alterations in the pathophysiologic processes of lung diseases. The recent studies on the analysis of EBC from both a genetic and epigenetic point of view were searched from database and reviewed. This review provides an overview of the current findings in the tracking of genomic and epigenetic alterations which are potentially effective in better management of cancer detection. In addition, respiratory microbiota DNA using EBC samples in association with pulmonary disease especially lung cancer were investigated. Various studies have concluded that EBC has a great potential for analysis of nuclear and mitochondrial DNA alterations as well as epigenetic modifications and identification of respiratory microbiome. Next-generation sequencing (NGS) based genomic profiling of EBC samples is recommended as a promising approach to establish personalized based prevention, diagnosis, treatment and post-treatment follow-ups for patients with lung diseases especially lung cancer.

Integration of platelet features in blood and platelet rich plasma for detection of lung cancer

OBJECTIVES

To determine whether the integration platelet features in blood and platelet rich plasma can establish a model to diagnose lung cancer and colon cancer, even differentiate lung malignancy from lung benign diseases.

METHODS

245 individuals including 159 lung cancer and 86 normal participants were divided into the training cohort and testing cohort randomly. Then, 32 colon cancers, 37 lung cancers, and 21 benign patients were enrolled into validate cohort. The whole blood and corresponding platelet rich plasma (PRP) samples from all participants were prospectively collected, and the platelet features were determined. The features which are statistically significant at the univariate analysis in the training cohort and reported significant features were entered the diagnostic model. A receiver operator characteristic (ROC) curve was drawn to evaluate the accuracy of the model in each cohort.

RESULTS

In the training cohort, multiple platelet features were significantly different in lung cancer patients, including MPV in whole blood, MPV, and platelet count in PRP and platelet recovery rate (PRR). For the training cohort, the diagnostic model for lung cancer performed well (AUC = 0.92). The probability distribution of lung cancers and controls in testing cohort were also separated well by the diagnostic model (AUC = 0.79). The diagnostic model for colon cancer also performed well (AUC = 0.79). The model also has a potential value in differentiating the lung malignancy from the benign (AUC = 0.69).

CONCLUSION

The PRR was first raised and used in the detection of lung cancer. This study identified a diagnostic model based on PRR and other platelet features in whole blood and PRP samples with the potential to distinguish patients with lung cancer or colon cancer from healthy controls. The model could also be used to distinguish between lung cancer from the benign disease.

Clinical study of serum IGFBP7 in predicting lymphatic metastasis in patients with lung adenocarcinoma

PURPOSE

To find serum tumor markers for predicting the presence of lymphatic metastasis in patients with lung adenocarcinoma, and to explore the diagnostic value of IGFBP7 in predicting if lymphatic metastasis occurs in lung adenocarcinoma.

METHODS

The concentration of IGFBP7 in the peripheral blood of 90 serum samples, including 30 patients with lung adenocarcinoma in situ, 30 patients with lung adenocarcinoma metastasis, and 30 normal controls were detected by ELISA. The data were analyzed statistically.

RESULTS

The concentration of IGFBP7 and D-dimer in the metastatic lung adenocarcinoma group was significantly higher than that in the lung adenocarcinoma in situ group (P < 0.05). The expression level of IGFBP7 in serum of patients with lung adenocarcinoma was associated with the clinical stage (P < 0.05) and lymphatic metastasis (P < 0.05). Using the receiver operating characteristic (ROC) curve, the area under the ROC curve of IGFBP7 was 0.901 (95% Confidence Interval was 0.806 to 0.996), and 0.5 was outside the 95% confidence interval (P < 0.05). The difference was statistically significant.

CONCLUSIONS

IGFBP7 can predict if the lung adenocarcinoma has lymphatic metastasis, which is helpful to improve the treatment of lung adenocarcinoma, and can be used as a new tumor marker to predict whether the lung adenocarcinoma has lymphatic metastasis or not.

Review and Comparison of Cancer Biomarker Trends in Urine as a Basis for New Diagnostic Pathways

Cancer is one of the major causes of mortality worldwide and its already large burden is projected to increase significantly in the near future with a predicted 22 million new cancer cases and 13 million cancer-related deaths occurring annually by 2030. Unfortunately, current procedures for diagnosis are characterized by low diagnostic accuracies. Given the proved correlation between cancer presence and alterations of biological fluid composition, many researchers suggested their characterization to improve cancer detection at early stages. This paper reviews the information that can be found in the scientific literature, regarding the correlation of different cancer forms with the presence of specific metabolites in human urine, in a schematic and easily interpretable form, because of the huge amount of relevant literature. The originality of this paper relies on the attempt to point out the odor properties of such metabolites, and thus to highlight the correlation between urine odor alterations and cancer presence, which is proven by recent literature suggesting the analysis of urine odor for diagnostic purposes. This investigation aims to evaluate the possibility to compare the results of studies based on different approaches to be able in the future to identify those compounds responsible for urine odor alteration.

Non-volatile compounds in exhaled breath condensate: review of methodological aspects

In contrast to bronchial and nasal lavages, the analysis of exhaled breath condensate (EBC) is a promising, simple, non-invasive, repeatable, and diagnostic method for studying the composition of airway lining fluid with the potential to assess lung inflammation, exacerbations, and disease severity, and to monitor the effectiveness of treatment regimens. Recent investigations have revealed the potential applications of EBC analysis in systemic diseases. In this review, we highlight the analytical studies conducted on non-volatile compounds/biomarkers in EBC. In contrast to other related articles, this review is classified on the basis of analytical techniques and includes almost all the applied methods and their methodological limitations for quantification of non-volatile compounds in EBC samples, providing a guideline for further researches. The studies were identified by searching the SCOPUS database with the keywords "biomarkers," "non-volatile compounds," "determination method," and "EBC."

A meta-analysis and bioinformatics exploration of the diagnostic value and molecular mechanism of miR-193a-5p in lung cancer

Lung cancer is a leading cause of mortality worldwide and despite recent improvements in lung cancer treatments patient mortality remains high. miR-193a-5p serves a crucial role in the initiation and development of cancer; it is necessary to understand the underlying molecular mechanisms of miR-193a-5p in lung cancer, which may enable the development of improved clinical diagnoses and therapies. The present study investigated the diagnostic value of peripheral blood and tissue miR-193a-5p expression using a microarray meta-analysis. Peripheral blood miR-193a-5p was revealed to be upregulated in patients with lung cancer. The pooled area under the curve (AUC) was 0.67, with a sensitivity and specificity of 0.74 and 0.56, respectively. Conversely, the peripheral tissue miR-193a-5p expression in patients with lung cancer was significantly downregulated. The pooled AUC was 0.83, and the sensitivity and specificity were 0.65 and 0.89, respectively. Through bioinformatics analysis, three Kyoto Encyclopedia of Genes and Genomes (KEGG) terms, pathways in cancer, prostate cancer and RIG-I-like receptor signaling pathway, were identified as associated with miR-193a-5p in lung cancer. In addition, in lung cancer, six key miR-193a-5p target genes, receptor tyrosine-protein kinase erbB-2 (ERBB2), nuclear cap-binding protein subunit 2 (NCBP2), collagen α-1(I) chain (COL1A1), roprotein convertase subtilisin/kexin type 9 (PCSK9), casein kinase II subunit α (CSNK2A1) and nucleolar transcription factor 1 (UBTF), were identified, five of which were significantly upregulated (ERBB2, NCBP2, COL1A1, CSNK2A1 and UBTF). The protein expression of ERBB2, NCBP2, COL1A1, CSNK2A1 and UBTF was also upregulated. NCBP2 and CSNK2A1 were negatively correlated with miR-193a-5p. The results demonstrated that miR-193a-5p exhibited opposite expression patterns in peripheral blood and tissue. Upregulated peripheral blood miR-193a-5p and downregulated tissue miR-193a-5p may be promising diagnostic biomarkers in lung cancer. In addition, the KEGG terms pathways in cancer, prostate cancer and RIG-I-like receptor signaling pathway may suggest which pathways serve vital roles in lung cancer by regulating miR-193a-5p. In addition, six genes, ERBB2, COL1A1, PCSK9, UBTF and particularly NCBP2 and CSNK2A1, may be key target genes of miR-193a-5p in lung cancer.

Potential lung carcinogenicity induced by chronic exposure to PM2.5 in the rat

Exposure to fine particulate matter (PM_2.5) may increase lung cancer risk, but the underlying mechanisms are poorly understood. This study explored the potential carcinogenicity in rat lung induced by chronic exposure to PM_2.5. Adult male rats (200-220 g) were treated with PM_2.5 (10 mg/kg body weight) by tracheal perfusion once per week for 1 year; the rats were killed, and expression of tumor markers (carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), squamous cell carcinoma antigen (SCCA)), cancer-related genes, and pathological changes were detected. Chronic treatment with PM_2.5 significantly increased SCCA and NSE expression in rat lung tissue and serum. Damaged lung tissue structure was observed by hematoxylin and eosin staining. Although no evidence of tumors was detected, the Wnt/β-catenin signaling, epithelial-mesenchymal transition, vascular endothelial growth factor, and epidermal growth factor receptor pathways were all activated or overexpressed and likely involved in the potential carcinogenicity in the rat model. Additionally, abnormal expression of the proto-oncogenes c-Myc and K-Ras and tumor suppressor p53 can be seen in lung tissue induced by PM_2.5 exposure. Chronic exposure to PM_2.5 has the potential to be carcinogenic in rat lung.

Detection of cancer embryo antigen and endothelin-1 in exhaled breath condensate: A novel approach to investigate non-small cell lung cancer

The present study aimed to investigate the clinical significance of cancer embryo antigen (CEA) and endothelin-1 (ET-1) in the exhaled breath condensate (EBC) of patients with non-small cell lung cancer (NSCLC). EBC samples were collected from 143 patients with NSCLC and 119 healthy individuals by using an EBC collector. The CEA and ET-1 levels in the EBC and serum were detected. The levels of CEA and ET-1 in the serum and EBC of the NSCLC group were higher compared with those of the healthy group. The level of CEA in the EBC of the adenocarcinoma group was higher compared with that in the squamous cell carcinoma group. The levels of CEA and ET-1 in the serum and EBC in stages III and IV were higher compared with those in stages I and II. The levels of CEA and ET-1 in the EBC were positively correlated with those in the serum, and furthermore, they exhibited high specificity and sensitivity. Thus, these parameters may be used to diagnose lung cancer. The detection of CEA and ET-1 in EBC may help the process of diagnosing and monitoring the progression of NSCLC.

Clinical evaluation and therapeutic monitoring value of serum tumor markers in lung cancer

BACKGROUND

Tumor markers CYFRA21-1, CEA, NSE, CA125, pro-GRP and SCC are routinely used for lung cancer. However, there has been no systematic evaluation of these markers in the same cohort. The aim of this study was to evaluate the diagnostic and therapeutic monitoring value of these markers.

METHODS

The levels of 6 serum tumor markers were measured in 392 patients, including 308 patients with non-small cell lung cancer (NSCLC) and 84 with small cell lung cancer (SCLC), and 116 patients with benign lung diseases and 144 healthy controls. 34 patients were followed up after operation and chemotherapy. Multiple logistic models and receiver operating characteristic (ROC) curves were used to evaluate their diagnostic value.

RESULTS

CEA, NSE, CA125 and pro-GRP in SCLC, and CYFRA21-1 as well as CEA in NSCLC, were higher than those in control groups. The level of CEA and CA125 were related to the clinical stages of NSCLC. Pro-GRP was significantly increased in extensive disease (ED) compared with limited disease (LD) in SCLC. CYFRA21-1 was reduced after the third and fifth treatment cycle respectively in patients who undergoing operation and without operation. NSE and pro-GRP were reduced significantly after the second and third treatment cycles, respectively.

CONCLUSIONS

CEA, NSE, CA125 and pro-GRP could serve as biomarkers for SCLC, and CEA and CYFRA21-1 could serve as biomarkers for NSCLC. Pro-GRP, CA125 and CEA were related to the clinical stages of lung cancer. CYFRA21-1, NSE and pro-GRP could be used for monitoring the effect of chemotherapy.

Exhaled Breath Condensate: Technical and Diagnostic Aspects

Purpose. The aim of this study was to evaluate the 30-year progress of research on exhaled breath condensate in a disease-based approach. Methods. We searched PubMed/Medline, ScienceDirect, and Google Scholar using the following keywords: exhaled breath condensate (EBC), biomarkers, pH, asthma, gastroesophageal reflux (GERD), smoking, COPD, lung cancer, NSCLC, mechanical ventilation, cystic fibrosis, pulmonary arterial hypertension (PAH), idiopathic pulmonary fibrosis, interstitial lung diseases, obstructive sleep apnea (OSA), and drugs. Results. We found 12600 related articles in total in Google Scholar, 1807 in ScienceDirect, and 1081 in PubMed/Medline, published from 1980 to October 2014. 228 original investigation and review articles were eligible. Conclusions. There is rapidly increasing number of innovative articles, covering all the areas of modern respiratory medicine and expanding EBC potential clinical applications to other fields of internal medicine. However, the majority of published papers represent the results of small-scale studies and thus current knowledge must be further evaluated in large cohorts. In regard to the potential clinical use of EBC-analysis, several limitations must be pointed out, including poor reproducibility of biomarkers and absence of large surveys towards determination of reference-normal values. In conclusion, contemporary EBC-analysis is an intriguing achievement, but still in early stage when it comes to its application in clinical practice.

Assessment of the exhalation kinetics of volatile cancer biomarkers based on their physicochemical properties

The current review provides an assessment of the exhalation kinetics of volatile organic compounds (VOCs) that have been linked with cancer. Towards this end, we evaluate various physicochemical properties, such as 'breath:air' and 'blood:fat' partition coefficients, of 112 VOCs that have been suggested over the past decade as potential markers of cancer. With these data, we show that the cancer VOC concentrations in the blood and in the fat span over 12 and 8 orders of magnitude, respectively, in order to provide a specific counterpart concentration in the exhaled breath (e.g., 1 ppb). This finding suggests that these 112 different compounds have different storage compartments in the body and that their exhalation kinetics depends on one or a combination of the following factors: (i) the VOC concentrations in different parts of the body; (ii) the VOC synthesis and metabolism rates; (iii) the partition coefficients between tissue(s), blood and air; and (iv) the VOCs' diffusion constants. Based on this analysis, we discuss how this knowledge allows modeling and simulating the behavior of a specific VOC under different sampling protocols (with and without exertion of effort). We end this review by a brief discussion on the potential role of these scenarios in screening and therapeutic monitoring of cancer.

Expression of miR-29c, miR-93, and miR-429 as potential biomarkers for detection of early stage non-small lung cancer

BACKGROUND

Altered expression of miRNA expression contributes to human carcinogenesis. This study was designed to detect aberrant miRNA expressions as a potential biomarker for early detection and prognosis prediction of non-small cell lung cancer (NSCLC).

METHODS

miRNA array was used to profile differentially expressed miRNAs and Taqman-based quantitative RT-PCR assays were used to analyze levels of miR-29c, miR-93, and miR-429 expression in NSCLC tissue samples, corresponding normal tissue samples, and serum samples from 70 NSCLC patients as well as in serum samples from 48 healthy controls.

RESULTS

Levels of miR-29c and miR-93 expression were upregulated in NSCLC tissues, while serum levels of miR-29c were also upregulated, but levels of serum miR-429 were decreased in NSCLC. Moreover, the levels of miR-429 expression in NSCLC tissues were associated with those in serum samples. Receiver operating characteristic (ROC) curve analysis showed that at the optimal cut-off point, the areas under the ROC curve for serum levels of miR-29c and miR-429 were 0.723 and 0.727, respectively, levels which are higher than that of carcinoma embryonic antigen (0.534) in diagnosis of stage I NSCLC. In addition, serum levels of miR-429 were associated with poor overall survival of NSCLC patients. Both univariate and multivariate analyses showed that serum miR-429 level was an independent prognostic predictor for NSCLC.

CONCLUSIONS

The results of the current study suggest that detection of serum miR-29c and miR-429 expression should be further evaluated as a novel, non-invasive biomarker for early stage NSCLC.