Soluble mesothelin-related protein in an asbestos-exposed population: the dust diseases board cohort study

Mesothelin Gene Variants Affect Soluble Mesothelin-Related Protein Levels in the Plasma of Asbestos-Exposed Males and Mesothelioma Patients from Germany

Malignant mesothelioma (MM) is a severe disease mostly caused by asbestos exposure. Today, one of the best available biomarkers is the soluble mesothelin-related protein (SMRP), also known as mesothelin. Recent studies have shown that mesothelin levels are influenced by individual genetic variability. This study aimed to investigate the influence of three mesothelin (MSLN) gene variants (SNPs) in the 5′-untranslated promoter region (5′-UTR), MSLN rs2235503 C > A, rs3764246 A > G, rs3764247 A > C, and one (rs1057147 G > A) in the 3′-untranslated region (3′-UTR) of the MSLN gene on plasma concentrations of mesothelin in 410 asbestos-exposed males without cancer and 43 males with prediagnostic MM (i.e., with MM diagnosed later on) from the prospective MoMar study, as well as 59 males with manifest MM from Germany. The mesothelin concentration differed significantly between the different groups (p < 0.0001), but not between the prediagnostic and manifest MM groups (p = 0.502). Five to eight mutations of the four SNP variants studied were associated with increased mesothelin concentrations (p = 0.001). The highest mesothelin concentrations were observed for homozygous variants of the three promotor SNPs in the 5′-UTR (p < 0.001), and the highest odds ratio for an elevated mesothelin concentration was observed for MSLN rs2235503 C > A. The four studied SNPs had a clear influence on the mesothelin concentration in plasma. Hence, the analysis of these SNPs may help to elucidate the diagnostic background of patients displaying increased mesothelin levels and might help to reduce false-positive results when using mesothelin for MM screening in high-risk groups.

Plasmonic Metasurfaces for Medical Diagnosis Applications: A Review

Plasmonic metasurfaces have been widely used in biosensing to improve the interaction between light and biomolecules through the effects of near-field confinement. When paired with biofunctionalization, plasmonic metasurface sensing is considered as a viable strategy for improving biomarker detection technologies. In this review, we enumerate the fundamental mechanism of plasmonic metasurfaces sensing and present their detection in human tumors and COVID-19. The advantages of rapid sampling, streamlined processes, high sensitivity, and easy accessibility are highlighted compared with traditional detection techniques. This review is looking forward to assisting scientists in advancing research and developing a new generation of multifunctional biosensors.

Serum Proteomics and Plasma Fibulin-3 in Differentiation of Mesothelioma From Asbestos-Exposed Controls and Patients With Other Pleural Diseases

INTRODUCTION

Malignant pleural mesothelioma (MPM) is difficult to diagnose. An accurate blood biomarker could prompt specialist referral or be deployed in future screening. In earlier retrospective studies, SOMAscan proteomics (Somalogic, Boulder, CO) and fibulin-3 seemed highly accurate, but SOMAscan has not been validated prospectively and subsequent fibulin-3 data have been contradictory.

METHODS

A multicenter prospective observational study was performed in 22 centers, generating a large intention-to-diagnose cohort. Blood sampling, processing, and diagnostic assessment were standardized, including a 1-year follow-up. Plasma fibulin-3 was measured using two enzyme-linked immunosorbent assays (CloudClone [used in previous studies] and BosterBio, Pleasanton, CA). Serum proteomics was measured using the SOMAscan assay. Diagnostic performance (sensitivity at 95% specificity, area under the curve [AUC]) was benchmarked against serum mesothelin (Mesomark, Fujirebio Diagnostics, Malvern, PA). Biomarkers were correlated against primary tumor volume, inflammatory markers, and asbestos exposure.

RESULTS

A total of 638 patients with suspected pleural malignancy (SPM) and 110 asbestos-exposed controls (AECs) were recruited. SOMAscan reliably differentiated MPM from AECs (75% sensitivity, 88.2% specificity, validation cohort AUC 0.855) but was not useful in patients with differentiating non-MPM SPM. Fibulin-3 (by BosterBio after failed CloudClone validation) revealed 7.4% and 11.9% sensitivity at 95% specificity in MPM versus non-MPM SPM and AECs, respectively (associated AUCs 0.611 [0.557-0.664], p = 0.0015) and 0.516 [0.443-0.589], p = 0.671), both inferior to mesothelin. SOMAscan proteins correlated with inflammatory markers but not with asbestos exposure. Neither biomarker correlated with tumor volume.

CONCLUSIONS

SOMAscan may prove useful as a future screening test for MPM in asbestos-exposed persons. Neither fibulin-3 nor SOMAscan should be used for diagnosis or pathway stratification.

Hitting the Bull's-Eye: Mesothelin's Role as a Biomarker and Therapeutic Target for Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive cancer with limited treatment options and poor prognosis. MPM originates from the mesothelial lining of the pleura. Mesothelin (MSLN) is a glycoprotein expressed at low levels in normal tissues and at high levels in MPM. Many other solid cancers overexpress MSLN, and this is associated with worse survival rates. However, this association has not been found in MPM, and the exact biological role of MSLN in MPM requires further exploration. Here, we discuss the current research on the diagnostic and prognostic value of MSLN in MPM patients. Furthermore, MSLN has become an attractive immunotherapy target in MPM, where better treatment strategies are urgently needed. Several MSLN-targeted monoclonal antibodies, antibody-drug conjugates, immunotoxins, cancer vaccines, and cellular therapies have been tested in the clinical setting. The biological rationale underpinning MSLN-targeted immunotherapies and their potential to improve MPM patient outcomes are reviewed.

ERS/ESTS/EACTS/ESTRO guidelines for the management of malignant pleural mesothelioma

The European Respiratory Society (ERS)/European Society of Thoracic Surgeons (ESTS)/European Association for Cardio-Thoracic Surgery (EACTS)/European Society for Radiotherapy and Oncology (ESTRO) task force brought together experts to update previous 2009 ERS/ESTS guidelines on management of malignant pleural mesothelioma (MPM), a rare cancer with globally poor outcome, after a systematic review of the 2009-2018 literature. The evidence was appraised using the Grading of Recommendations, Assessment, Development and Evaluation approach. The evidence syntheses were discussed and recommendations formulated by this multidisciplinary group of experts. Diagnosis: pleural biopsies remain the gold standard to confirm the diagnosis, usually obtained by thoracoscopy but occasionally via image-guided percutaneous needle biopsy in cases of pleural symphysis or poor performance status. Pathology: standard staining procedures are insufficient in ∼10% of cases, justifying the use of specific markers, including BAP-1 and CDKN2A (p16) for the separation of atypical mesothelial proliferation from MPM. Staging: in the absence of a uniform, robust and validated staging system, we advise using the most recent 2016 8th TNM (tumour, node, metastasis) classification, with an algorithm for pretherapeutic assessment. Monitoring: patient's performance status, histological subtype and tumour volume are the main prognostic factors of clinical importance in routine MPM management. Other potential parameters should be recorded at baseline and reported in clinical trials. Treatment: (chemo)therapy has limited efficacy in MPM patients and only selected patients are candidates for radical surgery. New promising targeted therapies, immunotherapies and strategies have been reviewed. Because of limited data on the best combination treatment, we emphasize that patients who are considered candidates for a multimodal approach, including radical surgery, should be treated as part of clinical trials in MPM-dedicated centres.

Follow-up of Soluble Mesothelin-Related Protein Levels in Participants With Asbestos-Related Disorders

Background

Asbestos exposure is associated with the development of the cancer malignant mesothelioma (MM). Measurement of soluble mesothelin-related protein (SMRP) has been suggested as a method for detection of MM in its early stages. We prospectively examined SMRP levels in participants with asbestos exposure who are a group at a high risk of development of MM.

Methods

This study was a follow-up of our cohort of 322 asbestos-exposed participants. No further participants developed MM or malignancy over the study period. Mean follow-up time was 22.9 months.

Results

Mean (standard deviation) SMRP levels at baseline and follow-up were 0.94 (0.79) and 0.91 (0.86) nmol/L (p = 0.1033), respectively. Mean SMRP levels of the healthy individuals exposed to asbestos at baseline was significantly lower than those of participants with asbestosis and pleural plaques alone; similar patterns were found on follow-up measurements. There was a statistically significant effect of age on serial SMRP measurements. Our study confirms higher levels in participants with nonmalignant asbestos-related disorders. Levels decreased in asbestos-related disorders other than asbestosis, where a small increase was observed. We did not detect any further cases of malignancy.

Conclusion

Monitoring programs for early detection of MM need to take into account increased SMRP levels found in benign asbestos-related diseases.

Mesothelioma Biomarkers: Discovery in Search of Validation

Malignant pleural mesothelioma (MPM) is an asbestos-related neoplasm that can only be treated successfully when correctly diagnosed and treated early. The asbestos-exposed population is a high-risk group that could benefit from sensitive and specific blood- or tissue-based biomarkers. We review recent work with biomarker development in MPM and literature of the last 20 years on the most promising blood- and tissue-based biomarkers. Proteomic, genomic, and epigenomic platforms are covered. SMRP is the only validated blood-based biomarker with diagnostic, monitoring and prognostic value. To strengthen development and testing of MPM biomarkers, cohorts for validation must be established by enlisting worldwide collaborations.

Mesothelioma Biomarkers: A Review Highlighting Contributions from the Early Detection Research Network

Malignant pleural mesothelioma (MPM) is an asbestos-related neoplasm, which can be treated successfully only if correctly diagnosed and treated in early stages. The asbestos-exposed population serves as a high-risk group that could benefit from sensitive and specific blood- or tissue-based biomarkers. This review details the recent work with biomarker development in MPM and the contributions of the NCI Early Detection Research Network Biomarker Developmental Laboratory of NYU Langone Medical Center. The literature of the last 20 years was reviewed to comment on the most promising of the blood- and tissue-based biomarkers. Proteomic, genomic, and epigenomic platforms as well as novel studies such as "breath testing" are covered. Soluble mesothelin-related proteins (SMRP) have been characterized extensively and constitute an FDA-approved biomarker in plasma with diagnostic, monitoring, and prognostic value in MPM. Osteopontin is found to be a valuable prognostic biomarker for MPM, while its utility in diagnosis is slightly lower. Other biomarkers, such as calretinin, fibulin 3, and High-Mobility Group Box 1 (HMGB1), remain under study and need international validation trials with large cohorts of cases and controls to demonstrate any utility. The EDRN has played a key role in the development and testing of MPM biomarkers by enlisting collaborations all over the world. A comprehensive understanding of previously investigated biomarkers and their utility in screening and early diagnosis of MPM will provide guidance for further future research.See all articles in this CEBP Focus section, "NCI Early Detection Research Network: Making Cancer Detection Possible."

ERS/ESTS/EACTS/ESTRO guidelines for the management of malignant pleural mesothelioma

The European Respiratory Society (ERS)/European Society of Thoracic Surgeons (ESTS)/European Association for Cardio-Thoracic Surgery (EACTS)/European Society for Radiotherapy and Oncology (ESTRO) task force brought together experts to update previous 2009 ERS/ESTS guidelines on management of malignant pleural mesothelioma (MPM), a rare cancer with globally poor outcome, after a systematic review of the 2009-2018 literature. The evidence was appraised using the Grading of Recommendations, Assessment, Development and Evaluation approach. The evidence syntheses were discussed and recommendations formulated by this multidisciplinary group of experts. Diagnosis: pleural biopsies remain the gold standard to confirm the diagnosis, usually obtained by thoracoscopy but occasionally via image-guided percutaneous needle biopsy in cases of pleural symphysis or poor performance status. Pathology: standard staining procedures are insufficient in ∼10% of cases, justifying the use of specific markers, including BAP-1 and CDKN2A (p16) for the separation of atypical mesothelial proliferation from MPM. Staging: in the absence of a uniform, robust and validated staging system, we advise using the most recent 2016 8th TNM (tumour, node, metastasis) classification, with an algorithm for pre-therapeutic assessment. Monitoring: patient's performance status, histological subtype and tumour volume are the main prognostic factors of clinical importance in routine MPM management. Other potential parameters should be recorded at baseline and reported in clinical trials. Treatment: (chemo)therapy has limited efficacy in MPM patients and only selected patients are candidates for radical surgery. New promising targeted therapies, immunotherapies and strategies have been reviewed. Because of limited data on the best combination treatment, we emphasise that patients who are considered candidates for a multimodal approach, including radical surgery, should be treated as part of clinical trials in MPM-dedicated centres.

Prediction of pneumoconiosis by serum and urinary biomarkers in workers exposed to asbestos-contaminated minerals

Workers processing nephrite, antigorite, or talc may be exposed to paragenetic asbestos minerals. An effective screening method for pneumoconiosis in workers exposed to asbestos-contaminated minerals is still lacking. The objective of this study was to assess the diagnostic accuracy of serum and urinary biomarkers for pneumoconiosis in workers exposed to asbestos-contaminated minerals. We conducted a case-control study in a cohort of stone craft workers in Hualien, where asbestos, nephrite, antigorite, and talc are produced. A total of 140 subjects were screened between March 2013 and July 2014. All subjects received a questionnaire survey and a health examination that included a physical examination; chest X-ray; and tests for standard pulmonary function, fractional exhaled nitric oxide, serum soluble mesothelin-related peptide (SMRP), fibulin-3, carcinoembryonic antigen (CEA), and urinary 8-Oxo-2'-deoxyguanosine (8-OHdG)/creatinine. After excluding subjects with uraemia and chronic obstructive pulmonary disease (COPD), we included 48 subjects with pneumoconiosis and 90 control subjects without pneumoconiosis for analysis. In terms of occupational history, 43/48 (90%) case subjects and 68% (61/90) of the control subjects had processed asbestos-contaminated minerals, including nephrite, antigorite, and talc. The case group had decreased pulmonary function in forced vital capacity (FVC), forced expiratory volume in one second, and forced expiratory flow between 25% and 75% of the FVC. The levels of SMRP, fibulin-3, urinary 8-OHdG/creatinine, and CEA were higher in the case group than in the control group. Subjects exposed to nephrite had significantly higher SMRP levels (0.84 ± 0.52 nM) than subjects exposed to other types of minerals (0.60 ± 0.30 nM). A dose-response relationship was observed between the SMRP level and the severity of pneumoconiosis. Machine learning algorithms, including variables of sex, age, SMRP, fibulin-3, CEA, and 8-OHdG/creatinine, can predict pneumoconiosis with high accuracy. The areas under the receiver operating characteristic curves ranged from 0.7 to 1.0. We suggest that SMRP and fibulin-3 could be used as biomarkers of pneumoconiosis in workers exposed to asbestos-contaminated minerals.

Treatment of Malignant Pleural Mesothelioma: American Society of Clinical Oncology Clinical Practice Guideline

Purpose To provide evidence-based recommendations to practicing physicians and others on the management of malignant pleural mesothelioma. Methods ASCO convened an Expert Panel of medical oncology, thoracic surgery, radiation oncology, pulmonary, pathology, imaging, and advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 1990 through 2017. Outcomes of interest included survival, disease-free or recurrence-free survival, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations. Results The literature search identified 222 relevant studies to inform the evidence base for this guideline. Recommendations Evidence-based recommendations were developed for diagnosis, staging, chemotherapy, surgical cytoreduction, radiation therapy, and multimodality therapy in patients with malignant pleural mesothelioma. Additional information is available at www.asco.org/thoracic-cancer-guidelines and www.asco.org/guidelineswiki .

CAR T-cell therapy for pancreatic cancer

Chimeric antigen receptor (CAR) T-cell therapy utilizes genetic engineering to redirect a patient's own T cells to target cancer cells. The remarkable results in hematological malignancies prompted investigating this approach in solid tumors such as pancreatic cancer. The complex tumor microenvironment, stromal hindrance in limiting immune response, and expression of checkpoint blockade on T cells pose hurdles. Herein, we summarize the opportunities, challenges, and state of knowledge in targeting pancreatic cancer with CAR T-cell therapy.

A recombinant polypeptide of the megakaryocyte potentiating factor is a potential biomarker in plasma for the detection of mesothelioma

Malignant mesothelioma (MM) is a fatal disease mostly associated with asbestos exposure and difficult to detect by non-invasive methods. This study aimed to use recombinant fragments of the megakaryocyte potentiating factor (MPF) for the development of cost-effective MPF ELISAs. Three polypeptides spanning the MPF region (MPF_1-148, MPF _34-288, MPF/MSLN_254-400) were produced in E.coli as maltose-binding protein hybrids. After isolation, Factor Xa digest, and purification, the polypeptides were used for the generation of rabbit antibodies and development of ELISAs. Forty-one MM patients with known histological subtype before tumor-specific treatment and 70 asbestos-exposed individuals free of any cancer were matched according to age, gender, and smoking. Plasma of all subjects was tested with the three newly developed polyclonal antibody-based ELISAs and a commercial mesothelin assay (MESOMARK™). The latter differentiated patients (median concentration 1.95 nM) from controls (median 1.07 nM, p < 0.0001) and showed an area under curve (AUC) of 0.77 in receiver operating characteristics (ROC) analysis. Of the MPF variants, exclusively the ELISA based on antibodies against the MPF_34-288 fragment displayed significantly (p = 0.0002) higher values in patients than in controls (median 1.61 nM versus 0.88 nM; AUC = 0.72). The combination of the MPF_34-288 and mesothelin displayed an improved ROC performance (AUC = 0.80). The MPF_34-288 ELISA could be a cost-effective and minimal-invasive contribution to support a diagnosis of mesothelioma, especially in regions with a limited medical care.

Malignant Mesothelioma Biomarkers: From Discovery to Use in Clinical Practice for Diagnosis, Monitoring, Screening, and Treatment

Malignant pleural mesothelioma is a highly aggressive tumor associated with asbestos exposure. There are few effective treatment options for mesothelioma, and patients have a very poor prognosis with a median survival of < 12 months from diagnosis. Biomarkers have been proposed as a cost-effective means of cancer management, and the search for a mesothelioma biomarker has been ongoing for the last 30 years. Many traditional soluble (glyco)protein biomarkers have been evaluated over this time, and an ever-increasing list of new biomarkers, including messenger RNA, DNA, microRNA, and antibodies, is being reported from biomarker discovery projects. To date, soluble mesothelin is the only tumor biomarker to receive US Food and Drug Administration approval for clinical use in mesothelioma. Mesothelin is a glycoprotein normally expressed on the surface of mesothelial cells, and in the cancerous state it can be present in circulation. Mesothelin has a limited expression on normal, nonmalignant tissue and is thus an attractive therapeutic target for mesothelin-positive tumors. In this review we will focus on the discovery and clinical usages of mesothelin and provide an update on other mesothelioma biomarkers and show how such biomarker studies might impact on the management of this deadly tumor in the future.

Advances in pleural diseases: what is the future for medical thoracoscopy?

PURPOSE OF REVIEW

Medical thoracoscopy provides the physician a window into the pleural space. The procedure allows biopsy of the parietal pleura under direct visualization with good accuracy. In addition, it achieves therapeutic goals of fluid drainage, guided chest tube placement, and pleurodesis.

RECENT FINDINGS

Comparable diagnostic yield is achieved with the flexi-rigid pleuroscope even though pleural biopsies are smaller using the flexible forceps as compared to rigid thoracoscopy. Flexi-rigid pleuroscopy is extremely well tolerated and can be performed safely as an outpatient procedure. Biopsy quality can be further enhanced with accessories that are compatible with the flex-rigid pleuroscope such as the insulated tip knife and cryoprobe.

SUMMARY

With more sensitive tools to image the pleura such as contrast-enhanced computed tomography, MRI, ultrasonography, PET, increased yield with image-guided biopsy as well as advances in cytopathology, what lies in the future for medical thoracoscopy remains to be seen. However, it is the authors' opinion that medical thoracoscopy will evolve with time, complement novel techniques, and continue to play a pivotal role in the evaluation of pleuropulmonary diseases.

Mesothelin (MSLN) methylation and soluble mesothelin-related protein levels in a Chinese asbestos-exposed population

OBJECTIVES

This study investigated the mesothelin (MSLN) methylation and its relationship with soluble mesothelin-related protein (SMRP) levels in participants stratified by asbestos exposure scenarios and benign asbestos-related diseases (ARDs).

METHODS

The presence of benign ARDs was confirmed through chest X-ray and the asbestos exposure history was obtained using a standardized questionnaire in this study, including 262 participants. Sera SMRP were measured using MESOMARK, and MSLN methylation in genomic DNA extracted from whole blood was detected by real-time methylation-specific PCR. Covariates were compared with SMRP concentrations using correlation analysis and the potential covariates affecting SMRP were determined by multiple linear regression analysis, and the distribution of methylation status was analyzed by Chi-square test.

RESULTS

There was a trend toward elevation of SMRP values in healthy individuals exposed to asbestos as compared with those without asbestos exposure. The highest median level of SMRP was 1.3 nM in subjects with asbestosis, followed by cases with pleura plaque and asbestosis (1.2 nM), pleura plaque (0.9 nM), healthy subjects with occupational exposure (0.9 nM), non-occupational exposure (0.8 nM), and mixed exposure (0.8 nM). Within asbestosis cases, those with higher profusion scores had higher SMRP values than those with lower profusion scores (1.6 vs. 0.8 nM). Based on multi-regression analysis, the trend toward elevation of SMRP remained significant in subjects with occupational exposure or in those with asbestosis, as compared with healthy subjects without exposure (p < 0.01), although body mass index had an effect on SMRP (p < 0.0001). Regardless of the differences in SMRP levels among these subgroups, MSLN methylation ranged from 80.5 to 92.5 %, with no significant difference. The elevated level of SMRP in asbestosis with higher profusion scores could not be attributed to low MSLN methylation status.

CONCLUSIONS

Our findings suggest that the elevation of SMRP is related to asbestos exposure and benign ARDs especially for cases with high profusion scores, which is independent of MSLN methylation.

Lung Function Profiles among Individuals with Nonmalignant Asbestos-related Disorders

Background

Inhalation of asbestos fibers can lead to adverse health effects on the lungs. This study describes lung function profiles among individuals with nonmalignant asbestos-related disorders (ARDs).

Methods

The study population was from the Workers' Compensation (Dust Diseases) Board of New South Wales, Sydney, Australia. Lung function measurements were conducted in males with asbestosis (n = 26), diffuse pleural thickening (DPT; n = 129), asbestosis and DPT (n = 14), pleural plaques only (n = 160) and also apparently healthy individuals with a history of asbestos exposure (n = 248). Standardized spirometric and single-breath diffusing capacity for carbon monoxide (DL_CO) measurements were used.

Results

Mean age [standard deviation (SD)] was 66.7 (10.3) years for all participants. Current and ex-smokers among all participants comprised about 9.0% and 54.8%, respectively. Median pack-years (SD) of smoking for ex- and current-smokers were 22.7 (19.9). Overall 222 participants (38.6%) and 139 participants (24.2%) had forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC) measurements < 80% predicted, and 217 participants (37.7%) had FEV₁/FVC results < 70%. A total of 249 individuals (43.8%) had DLco values < 80% predicted and only 75 (13.2%) had DLco/VA results < 80% predicted. A total of 147 participants (25.6%) had peak expiratory flow (PEF) measurements < 80% predicted. The presence of ARDs lowered the lung function measurements compared to those of healthy individuals exposed to asbestos.

Conclusion

Lung function measurement differs in individuals with different ARDs. Monitoring of lung function among asbestos-exposed populations is a simple means of facilitating earlier interventions.

Significance of serum mesothelin in an asbestos-exposed population in the Czech Republic

AIMS

Pleural mesothelioma is a highly aggressive and difficult-to-treat form of cancer induced by asbestos in 80-90% of cases. The population group most at risk of the condition are asbestos-exposed workers. Mesothelin or soluble mesothelin-related protein (SMRP) is studied as a potential marker of mesothelioma in the at-risk population.

METHODS

The study comprised 239 subjects with a mean duration of occupational exposure to asbestos of 19.9 years. In all of them, a complete medical history was taken, focused on exposure duration and a physical examination, a chest X-ray or other imaging investigations and a lung function test were performed. Their serum SMRP levels were measured and biopsy samples were taken to diagnose pleural disease. Based on the above examinations, the subjects were classified into subgroups and serum SMRP concentrations were statistically analyzed with respect to individual parameters.

RESULTS

In asbestos-exposed individuals, mesothelin levels were significantly higher in those with pathological X-ray findings than in those with normal X-ray results (0.78 ± 0.63 vs. 0.50 ± 0.35, P<0.0001). The group of patients with benign disease had statistically significantly higher mesothelin levels than those with normal X-ray findings (0.755 ± 0.543 vs. 0.50 ± 0.35, P<0.001). In the group with present malignant processes, mesothelin levels were higher than in individuals with benign disease (1.19 ± 0.89 vs. 0.76 ± 0.54, P=0.015). Only a weak correlation was found between mesothelin levels and asbestos exposure duration. There were relatively high sensitivity and high specificity (75% and 90.6%, respectively) of serum mesothelin for pleural mesothelioma. However, given the small number of mesothelioma cases in the group, the results cannot be considered as statistically significant.

CONCLUSIONS

In persons followed up for asbestos exposure, increased mesothelin levels signalize pathological processes in the chest and correlate with severity of the disease. The study suggests that mesothelin cannot be considered a reliable marker for the early stage of malignant degeneration of pleural disease but only an additional criterion for examination of the followed-up individuals.

Asbestos and the lung in the 21st century: an update

The asbestos-related disorders (ARDs) are currently of significant occupational and public health concern. Asbestos usage has been banned in most developed countries, but asbestos is still used in many developing countries and the number of cases of ARDs worldwide is rising. Many countries are now experiencing an epidemic of ARDs that is the legacy of occupational exposure in the 1960s-1980s because of the long latency period between asbestos exposure and manifestation of disease. It is likely that asbestos-related mortality and morbidity will continue to increase. Although the most feared complications of asbestos inhalation are the malignant conditions such as mesothelioma and lung cancer, asbestos inhalation more frequently results in benign conditions such as pleural plaques, diffuse pleural thickening, and asbestosis (pulmonary fibrosis due to asbestos exposure). Over recent years, there have been changes in the epidemiology of mesothelioma, in clinical management of ARDs and developments in new techniques for early detection of malignancy. This review provides an update on the respiratory manifestations of asbestos exposure and also considers advances in screening methods that may affect future management in the workplace.

A predictive equation to adjust for clinical variables in soluble mesothelin-related protein (SMRP) levels

BACKGROUND

Malignant mesothelioma (MM) is an aggressive pleural tumor which is difficult to diagnose in its early stages. Thus, biomarkers for MM including soluble mesothelin-related protein (SMRP) are currently an area of intense research interest. However, SMRP is affected by several factors other than malignancy which need to be taken into account in the individual patient. This study aimed to evaluate factors required to adjust SMRP levels for such variables and produce a useful prediction equation for clinical application.

METHODS

Serum SRMP levels were measured in 535 subjects formerly exposed to asbestos and silica, including many with asbestos-related disorders (ARDs). Linear regression analyses were used to quantify the strength and “ direction ” of the relationship between SMRP and several independent variables,and 2 × 2 tables were used to determine the diagnostic accuracy of SMRP levels, taking into account clinical variables.

RESULTS

SMRP levels were affected by age and glomerular filtration rate (GFR), which were strong confounders in this study. Body mass index (BMI) was also an initial confounder but lost significance after other factors were taken into account.SMRP was also affected by smoking. Poor sensitivity (15.1 % )for SMRP values among subjects with non-malignant asbestos-related disorders was found when compared to currently healthy subjects with a history of asbestos exposure.

CONCLUSIONS

The present study proposes an equation based on age and GFR to improve diagnostic accuracy of SMRP.The poor sensitivity of SMRP found in this study suggests that further work is needed to fi nd new candidate biomarkers for diagnosing early stage MM.

[Malignant pleural mesothelioma: diagnosis and treatment]

Malignant pleural mesothelioma (MPM) is a rare and aggressive tumor issued from the mesothelial surface of the pleural space. A previous exposure to asbestos is the main risk factor of mesothelioma. Clinical signs are most of the time late and unspecific. Chest CT-scan, a key imaging procedure, usually shows a (unilateral) pleurisy associated with pleural nodular thickening. PET-scan associated with CT-scan may help to differenciate MPM from pleural benign tumors but it is not recommended for the diagnosis of MPM, as well as chest resonance magnetic imaging and blood or pleural fluid biomarkers, including soluble mesothelin still under investigation. The diagnosis of MPM is based on histology using essentially immunohistochemistry on pleural biopsies best obtained by thoracoscopy. The treatment of MPM relies mostly on chemotherapy. Surgery, pleurectomy/decortication or extrapleural pneumonectomy, is not recommended outside a clinical trial, as well as adjuvant chest radiotherapy. Prophylactic irradiation of chest scars and drains, validated by the French guidelines in 2005, is however highly discussed at the international level. Finally, numerous research studies presently assess the value of targeted therapies and biomarkers in MPM, opening new perspectives in the management of this cancer.

Increased circulating miR-625-3p: a potential biomarker for patients with malignant pleural mesothelioma

INTRODUCTION

We investigated the ability of cell-free microRNAs (miRNAs) in plasma and serum to serve as a biomarker for malignant mesothelioma (MM).

METHODS

Using miRNA microarrays, we profiled plasma samples from MM patients and healthy controls. miRNAs with significantly different abundance between cases and controls were validated in a larger series of MM patients and in an independent series of MM patients using quantitative real-time polymerase chain reaction. Levels of candidate miRNAs were also quantified in MM tumor samples.

RESULTS

We compared cell-free miRNA profiles in plasma from MM patients with healthy controls. Reviewing 90 miRNAs previously reported to be associated with MM, we found that the levels of two miRNAs, miR-29c* and miR-92a, were elevated in plasma samples from MM patients. In addition, we identified 15 novel miRNAs present at significantly higher levels in the plasma of MM patients. Further analysis of candidate miRNAs by real time-quantitative polymerase chain reaction confirmed that one of them, miR-625-3p, was present in significantly higher concentration in plasma/serum from MM patients and was able to discriminate between cases and controls, in both the original and the independent series of patients. MiR-625-3p was also found to be up-regulated in tumor specimens from a group of 18 MM patients, who underwent extrapleural pneumonectomy.

CONCLUSION

Our data confirm the potential of miR-29c* and miR-92a as candidate tumor markers and reveal that miR-625-3p is a promising novel diagnostic marker for MM.

Mesothelioma - Update on Diagnostic Strategies

Malignant pleural mesothelioma (MPM) can be a challenging diagnosis for clinicians to make as it is often difficult to distinguish from benign asbestos pleural effusions and metastatic carcinomas. In this review, we present a case of MPM and discuss clinical manifestations, traditional diagnostic techniques, and the role of cytopathologic immunostains and serum biomarkers in the diagnosis of MPM.

Association of biomarker levels with severity of asbestos-related diseases

Objectives

Asbestos-related diseases (ARDs) have increased globally over the decades, causing an economic burden and increased health care costs. It is difficult to predict the risk of development of ARDs and of respiratory disability among workers with a history of asbestos exposure. Blood based biomarkers have been reported as promising tools for the early detection of malignant mesothelioma. This study investigated whether serum soluble mesothelin-related peptide (SMRP) would reflect severity of disablement in compensable ARDs.

Methods

SMRP levels were measured in a cohort of 514 asbestos-exposed subjects. Severity of ARDs was assessed by a Medical Authority comprising four specially qualified respiratory physicians. Severity of ARDs and SMRP levels were compared.

Results

Mean (standard deviation) serum SMRP level in the population with compensable ARDs (n = 150) was 0.95 (0.65) nmol/L, and was positively associated with disability assessment (p = 0.01). Mean SMRP level in healthy asbestos-exposed subjects was significantly lower than those with pleural plaques (p < 0.0001) and in subjects with ARDs who received compensation (p < 0.01).

Conclusion

This study indicates that serum SMRP levels correlate with severity of compensable ARDs. Serum SMRP could potentially be applied to monitor progress of ARDs. Further prospective work is needed to confirm the relationship between SMRP and disability assessment in this population.

Identification of miRNA-103 in the cellular fraction of human peripheral blood as a potential biomarker for malignant mesothelioma--a pilot study

Background

To date, no biomarkers with reasonable sensitivity and specificity for the early detection of malignant mesothelioma have been described. The use of microRNAs (miRNAs) as minimally-invasive biomarkers has opened new opportunities for the diagnosis of cancer, primarily because they exhibit tumor-specific expression profiles and have been commonly observed in blood of both cancer patients and healthy controls. The aim of this pilot study was to identify miRNAs in the cellular fraction of human peripheral blood as potential novel biomarkers for the detection of malignant mesothelioma.

Methodology/Principal Findings

Using oligonucleotide microarrays for biomarker identification the miRNA levels in the cellular fraction of human peripheral blood of mesothelioma patients and asbestos-exposed controls were analyzed. Using a threefold expression change in combination with a significance level of p<0.05, miR-103 was identified as a potential biomarker for malignant mesothelioma. Quantitative real-time PCR (qRT-PCR) was used for validation of miR-103 in 23 malignant mesothelioma patients, 17 asbestos-exposed controls, and 25 controls from the general population. For discrimination of mesothelioma patients from asbestos-exposed controls a sensitivity of 83% and a specificity of 71% were calculated, and for discrimination of mesothelioma patients from the general population a sensitivity of 78% and a specificity of 76%.

Conclusions/Significance

The results of this pilot study show that miR-103 is characterized by a promising sensitivity and specificity and might be a potential minimally-invasive biomarker for the diagnosis of mesothelioma. In addition, our results support the concept of using the cellular fraction of human blood for biomarker discovery. However, for early detection of malignant mesothelioma the feasibility of miR-103 alone or in combination with other biomarkers needs to be analyzed in a prospective study.

Malignant mesothelioma

Malignant mesothelioma (MM) is an aggressive tumour that commonly affects the mesothelial surfaces of the pleural and peritoneal cavities, and occasionally, the tunica vaginalis and the pericardium. Formerly a rare tumour, MM is increasing in incidence in Australia due to the heavy nationwide use of asbestos from 1940 until the 1980s. The incidence is expected to peak in Australia in the next decade, mirroring the long latency period between asbestos exposure and development of MM. Diagnosis of MM can be difficult. Definitive pathological diagnosis is required and it often requires an experienced pathologist to differentiate MM from other benign or malignant processes. Treatment of MM requires a multidisciplinary approach, regardless of palliative or curative intent. Treatment options, such as surgery, chemotherapy, radiotherapy and active symptom control or a combination of these, may be used. Further research is needed to advance the therapeutic options for MM, and strategies to realize personalisation of therapy through discovery of predictive markers. In the Australian society where asbestos contamination of the built environment is very high, education and stringent public health measures are required to prevent a second wave of increased MM incidence.

Biomarkers in malignant mesothelioma: diagnostic and prognostic role of soluble mesothelin-related peptide

Soluble mesothelin-related peptide (SMRP) is a biomarker that has been proposed for differential diagnosis from pleural metastatic cancer, as well as prognosis and treatment monitoring of malignant pleural mesothelioma (MM). The aim of this study was to evaluate the role of SMRP in clinic management of MM. We assayed the SMRP concentrations in 354 subjects: 109 healthy volunteers with no history of exposure to asbestos, 26 patients with previous occupational asbestos exposure but who were free from pleural or parenchymal disease, 48 patients with asbestosis, 110 patients with pleural plaques, 25 patients with lung cancer, and 36 patients with MM. We also tested SMRP titers in 2 patients with MM at 5 different times of the disease, to evaluate the trend of the biomarker in the course of therapy. Our data confirm previous experiences with the use of SMRP as a diagnostic marker of MM. Low SMRP levels at diagnosis seem to have a positive prognostic significance.

Translational advances in pleural malignancies

Pleural malignancies, including primary malignant pleural mesothelioma and secondary pleural metastasis of various tumours resulting in malignant pleural effusion, are frequent and lethal diseases that deserve devoted translational research efforts for improvements to be introduced to the clinic. This paper highlights select clinical advances that have been accomplished recently and that are based on preclinical research on pleural malignancies. Examples are the establishment of folate antimetabolites in mesothelioma treatment, the use of PET in mesothelioma management and the discovery of mesothelin as a marker of mesothelioma. In addition to established translational advances, this text focuses on recent research findings that are anticipated to impact clinical pleural oncology in the near future. Such progress has been substantial, including the development of a genetic mouse model of mesothelioma and of transplantable models of pleural malignancies in immunocompetent hosts, the deployment of stereological and imaging methods for integral assessment of pleural tumour burden, as well as the discovery of the therapeutic potential of aminobiphosphonates, histone deacetylase inhibitors and ribonucleases against malignant pleural disease. Finally, key obstacles to overcome towards a more rapid advancement of translational research in pleural malignancies are outlined. These include the dissection of cell-autonomous and paracrine pathways of pleural tumour progression, the study of mesothelioma and malignant pleural effusion separately from other tumours at both the clinical and preclinical levels, and the expansion of tissue banks and consortia of clinical research of pleural malignancies.

Early stages of mesothelioma, screening and biomarkers

The early diagnosis of mesothelioma is notoriously difficult, both from a clinical and pathological perspective. Patients often undergo several medical investigations without definitive diagnosis. The discovery of biomarkers that can be assessed in pleural effusions, histological samples, and serum may assist with the difficult early diagnosis of mesothelioma. In this chapter we focus on those markers that have been examined in the setting of either early diagnosis of mesothelioma in symptomatic individuals or that have been proposed as suitable for screening of asbestos-exposed individuals, with an emphasis on cytology and histology.

Clinical significance of pleural effusion mesothelin in malignant pleural mesothelioma

BACKGROUND

Malignant pleural mesothelioma (MPM) is an aggressive malignant tumor of mesothelial origin associated with asbestos exposure. MPM has a limited response to conventional chemotherapy and radiotherapy, so early diagnosis of MPM is very important. This study investigated the pleural effusion mesothelin levels in patients with MPM and compared them to those of a population with a non-malignant pleuritis or lung cancer involving malignant pleural effusion.

METHODS

The pleural effusion mesothelin concentrations were measured in 45 MPM patients and 53 non-MPM individuals (24 individuals with non-malignant pleural effusions and 29 individuals with lung cancer involving malignant pleural effusion).

RESULTS

This study demonstrated that patients with MPM had significantly higher pleural effusion mesothelin levels than a population with non-malignant pleuritis or lung cancer involving malignant pleural effusion. The difference in overall survival between the groups with pleural effusion mesothelin levels lower and higher than the assumed cut-off of 10 nM was significant.

CONCLUSIONS

The data suggest that the pleural effusion mesothelin concentration could be useful as an aid for the diagnosis of MPM.

Detection of integrin-linked kinase in the serum of patients with malignant pleural mesothelioma

OBJECTIVE

Integrin-linked kinase, which is relevant to neoplastic transformation, is highly expressed in malignant pleural mesothelioma. Recently, detection of integrin-linked kinase in serum of patients with ovarian cancer has been reported. This study asks whether integrin-linked kinase can also be detected in serum of patients with malignant pleural mesothelioma and whether serum level has diagnostic or prognostic relevance for that disease.

METHODS

A sandwich enzyme-linked immunosorbent assay was designed to detect integrin-linked kinase and applied to serum samples from 46 patients with malignant pleural mesothelioma, 98 patients with other malignant chest disease, and 23 patients with benign chest disease. Integrin-linked kinase serum concentration and clinical data were correlated statistically.

RESULTS

Median serum integrin-linked kinase concentration was significantly higher in malignant pleural mesothelioma (8.89 ng/mL) than in other malignant chest disease (0.66 ng/mL) or benign chest disease (0.78 ng/mL, P < .001). There was no relevant correlation of serum integrin-linked kinase with cell lysis parameters (R(2) < 0.1). Serum integrin-linked kinase concentration greater than 2.48 ng/mL had diagnostic sensitivity of 80%, specificity of 95%, positive predictive value of 85.7%, negative predictive value of 92.7%, and overall accuracy of 91% for distinction between malignant pleural mesothelioma and other diseases. Serum integrin-linked kinase concentration in malignant pleural mesothelioma was independent of histologic subtype or asbestos exposure. There was no statistically significant impact of serum integrin-linked kinase concentration on prognosis.

CONCLUSIONS

Integrin-linked kinase can be detected in serum of patients with malignant pleural mesothelioma and may be a diagnostic marker for the disease.

Soluble markers for diagnosis of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a highly aggressive and invasive tumor, whose incidence is expected to peak, in many countries, at the end of the present decade, 20–40 years after the peak of asbestos use (asbestos being the most important etiological factor). MPM has a poor prognosis, in part, owing to a difficult and often late diagnosis hindered by a lack of available tests able to diagnose or predict this cancer in its early stages. Recently, there has been increased interest in noninvasive, economic and well-accepted diagnostic tests for screening of asbestos-exposed subjects, as well as for monitoring response of MPM patients to treatment. Several markers have been studied in biofluids, such as serum, plasma and pleural effusions, especially using ELISA, and some of them are still under investigation. However, only mesothelin and ostepontin have proven levels of sensitivity and specificity that are worth testing in the clinical setting.

[Management of pleural disease]

In view of the presentations in the First National Forum of Trainee Pneumologists, the present article focuses on infectious pleural effusions and on the study of possible markers of malignant disease in asbestos-exposed individuals. The yield of the distinct techniques for the diagnosis of tuberculous pleural effusion is assessed, with emphasis on analysis of sputum and pleural samples (fluid and tissue) for Mycobacteriumtuberculosis. The utility of adenosine deaminase (ADA) (in the absence of empyema, ADA > 70 U/l is diagnostic of tuberculous pleurisy, while values of less than 40 U/l exclude this diagnosis) and interferon gamma in pleural fluid (cut off: 3.7 Ul/ml) is also discussed. The management of complicated parapneumonic pleural effusions is stratified in four categories, depending on the anatomical and morphological (size and eventual presence of loculations), bacteriological (positivity or negativity of pleural fluid culture) and biochemical (pH/glucose) characteristics of the effusion. Finally, recently developed markers for the evaluation and follow-up of asbestos-exposed individuals are described, with special emphasis on serum determination of mesothelin levels, which seem highly promising as a marker of the development of mesothelioma in these cases. A multicenter study currently being performed in Spain found that soluble mesothelin-related protein (SMRP) levels higher than 0.55 nmol/L showed a sensitivity and specificity of 72% for the diagnosis of epithelial malignant mesothelioma.

Plasma versus serum levels of osteopontin and mesothelin in patients with malignant mesothelioma--which is best?

BACKGROUND

Blood-based markers for malignant mesothelioma (MM), particularly soluble mesothelin and osteopontin, are currently of great clinical interest. As there is some concern about the sensitivity of osteopontin in serum versus plasma, we compared them in the same patient population to mesothelin.

METHODS

Soluble mesothelin and osteopontin concentrations were determined by commercial assays in blood samples from 66 patients with pleural MM, 47 patients with non-malignant asbestos-related lung or pleural disease, 42 patients with other benign pleural and lung diseases and 21 patients with lung cancer.

RESULTS

Soluble mesothelin and osteopontin in serum and plasma were significantly elevated in MM patients compared to patients with benign lung and pleural disease. At a level of specificity of 95% relative to patients with benign disease, the sensitivity of mesothelin in serum and plasma at presentation with symptoms was 67%, and for osteopontin in the plasma was 40% and in the serum was 20% for MM patients. Combining the serum mesothelin and plasma osteopontin markers using a logistic regression model did not significantly increase the area under the receiver operator curve.

CONCLUSION

Plasma osteopontin has a superior diagnostic accuracy to serum. As the choice of blood sample type has limit effect on soluble mesothelin sensitivity, plasma should be collected for biomarker evaluation in patients suspected of having mesothelioma.

[Guidelines of the European Respiratory Society and the European Society of Thoracic Surgeons for the management of malignant pleural mesothelioma]

恶性胸膜间皮瘤（malignant pleural mesothelioma, MPM）是一种罕见肿瘤，但发病率正逐渐上升，且预后较差。2008年，欧洲呼吸学会（European Respiratory Society, ERS）和欧洲胸外科医师学会（European Society of Thoracic Surgeons, ESTS）特别工作组召集各方专家计划制定MPM诊治经验及更新指南。

为了使MPM得到及时准确的诊断，专家推荐对患者实施胸腔镜检查，有手术禁忌和胸腔粘连的病例除外。约10%的病例采用标准染色方法无法获得满意的结果。因此我们推荐在胸膜活检的基础上，采用特异性免疫组化标志物。由于目前缺乏一个统一的、切实有效的分期系统，我们推荐应用最新的TNM分期，并且提出三个阶段的治疗前评估。在MPM的治疗中，患者的体力状态评分和组织亚型是目前唯一的、具有重要临床价值的预后因素。在临床试验中，应对其它潜在因素进行初步探讨并予以报道。MPM对化疗高度耐受，仅有少数患者可接受根治性手术。本文对新的治疗方法和策略进行了综述。

目前由于最佳综合治疗的资料有限，适合采用多种方案联合治疗策略的患者应被纳入专业机构的前瞻性试验中。

fTwo novel biomarkers, mesothelin and HE4, for diagnosis of ovarian carcinoma

INTRODUCTION: There is a need to improve the diagnosis and prognosis of ovarian carcinoma, particularly the serous type of cancer. Mesothelin and HE4 are two novel biomarkers which are expressed in serous ovarian carcinoma and can be measured in serum and other body fluids, including urine, by using ELISA. The measurement of antibodies to these markers can provide additional useful information. AREAS COVERED: A literature search was performed to as recent as December 1 2010, using the Internet (e.g. PubMed) on articles concerning mesothelin and HE4 for the diagnosis of ovarian carcinoma. The authors also included up to date recent information from the research performed in their own laboratory. EXPERT OPINION: The combination of CA125 with HE4 facilitates the triaging of women with a pelvic mass and detects more stage I/II tumors than CA125, the present 'gold standard', when used alone. Assaying urine for HE4 or mesothelin may detect early ovarian carcinoma more often than assaying serum. Antibodies to mesothelin and HE4 are more frequent in women with ovarian carcinoma or with certain types of infertility than in controls. No presently available biomarker or multi-marker panel lends itself to screening large populations of symptomless women to make possible detection of high grade serous ovarian carcinoma at stage I or II. The authors anticipate, within the next 5 years, that a greater emphasis will be given to the fact that the different subtypes of ovarian carcinoma represent different types of disease. Each different type of disease will require a different diagnostic approach and more efforts will focus on high grade serous ovarian carcinoma for which the clinical need is the greatest.