Management of Malignant Pleural Mesothelioma

Diffuse Pleural Mesothelioma: A Challenge in Early Diagnosis

We present the clinical case of a 58-year-old female patient, a smoker with occupational exposure to respiratory toxins, who was admitted to our clinic following evaluation in an emergency department, where she was diagnosed with a moderate right pleural effusion. Upon admission, the patient exhibited respiratory symptoms, including progressive dyspnea with a moderate exertion threshold, right posterior pleuritic chest pain radiating anteriorly, occasional episodes of low-grade fever, and persistent febrile symptoms lasting approximately two weeks. In this clinical context, the diagnostic process was guided by the presence of right pleural effusion syndrome, which was refractory to conservative medical therapy. This necessitated a careful and stepwise expansion of investigations, ultimately leading to the diagnosis of malignant pleural mesothelioma. This case underscores the diagnostic challenges posed by pleural effusion, the necessity of adhering to the diagnostic algorithm, and the critical role of the multidisciplinary team. The diagnostic approach, often complex and challenging, necessitates a multidimensional strategy that integrates the correlation and synthesis of data obtained through anamnesis, alongside advanced diagnostic procedures such as pleural biopsy, which remains the gold standard. This comprehensive process is essential for formulating a diagnostic suspicion, with the final diagnosis intended to be one of exclusion.

Pleural Neoplasms-What Could MRI Change?

The primary pleural neoplasms constitute around 10% of the pleural tumors. The currently recommended method for their imaging is CT which has been shown to have certain limitations. Strong development of the MRI within the last two decades has provided us with a number of sequences that could potentially be superior to CT when it comes to the pleural malignancies' detection and characterization. This literature review discusses the possible applications of the MRI as a diagnostic tool in patients with pleural neoplasms. Although selected MRI techniques have been shown to have a number of advantages over CT, further research is required in order to confirm the obtained results, broaden our knowledge on the topic, and pinpoint the sequences most optimal for pleural imaging, as well as the best methods for reading and analysis of the obtained data.

Intramedullary Metastasis to the Cervical Spinal Cord from Malignant Pleural Mesothelioma: Review of the Literature and Case Reports

Context:

Malignant mesothelioma is an aggressive tumor; median survival of patients following diagnosis is 12 months.

Aims:

Pleural malignant mesothelioma tends to spread along preexisting tissue planes and has the rare ability to spread along the nerve root into the spinal cord. In our case, there is an evidence of exceptional direct hematogenous spread to the spinal cord by the spinal branch of the intercostal arteries or the veins of Batson's plexus.

Settings and Design:

The authors report a case of intramedullary hematogenous metastasis to the cervical spinal cord from malignant mesothelioma, with a review of the literature.

Materials and Methods:

A 68-year-old male was admitted to our department because of a slowly progressive mild weakness of both low extremities, more pronounced on the left side. The patient has been treated for a malignant mesothelioma with left thoracotomy and subsequently underwent radiotherapy. Magnetic resonance imaging of the cervical-thoracic spine revealed a contrast-enhancing intramedullary expansive lesion of the left half of the spinal cord at the C6–C7 level.

Results:

The patient underwent surgical treatment through a C6–C7 laminectomy. Through a median posterior spinal cord incision, an intramedullary grayish lesion was completely removed. The paraparesis progressively improved and 20 days after surgery, the patient had regained normal lower extremity function.

Conclusions:

Malignant mesothelioma can spread to the spinal canal by the direct extension through the intervertebral foramina, by hematogenous spread to the spinal meninges, and by perineural growth along a single nerve root. The cleavage plane of the tissue may determine whether a successful gross total resection can be achieved with a good outcome for the patient.

Immune Tolerance Therapy: A New Method for Treatment of Traumatic Brain Injury

Objective:

Due to the special anatomical structure and pathophysiological mechanism of the central nervous system (CNS), there is a big difference between the repair of brain injury and other systems of the body. More and more evidence shows that targetedly reducing the autoimmune response of brain tissue without affecting the immune function in other parts of the body will be the best optimized treatment for brain injury.

Data Sources:

This review was based on data in articles published in PubMed up to June 5, 2017, with the following keywords: “immune tolerance”, “traumatic brain injury”, and “central nervous system”.

Study Selection:

Original articles and critical reviews on immune tolerance and brain damage were selected for this review. References of the retrieved articles were also screened to search for potentially relevant papers.

Results:

The CNS is isolated from the immune system through the blood-brain barrier. After brain injury, brain antigens are released into the systemic circulation to induce damaging immune responses. Immune tolerance can effectively reduce the brain edema and neurological inflammatory response after brain injury, which is beneficial to the recovery of neurological function. The clinical application prospect and theoretical research value of the treatment of immune tolerance on traumatic brain injury (TBI) is worth attention.

Conclusions:

The establishment of immune tolerance mechanism has a high clinical value in the treatment of TBI. It opens up new opportunities for the treatment of brain damage.

Tumour associated lymphocytes in the pleural effusions of patients with mesothelioma express high levels of inhibitory receptors

OBJECTIVE

Pleural effusion (PE) is a common feature of malignant pleural mesothelioma. These effusions typically contain lymphocytes and malignant cells. We postulated that the PE would be a source of lymphocytes for analysis of tumor immune milieu. The aim of this study was to compare the phenotype and T cell receptor usage of pleural effusion T cells with paired concurrently drawn peripheral blood lymphocytes. We used multi-parameter flow cytometry and high-throughput T cell receptor sequencing to analyse peripheral blood and pleural effusion mononuclear cells.

RESULTS

Both CD8⁺ and CD4⁺ T cells from effusion showed increased expression of T cell inhibitory receptors PD-1, LAG-3 and Tim-3 compared to blood. Comprehensive T cell receptor sequencing on one of the patients showed a discordant distribution of clonotypes in the antigen-experienced (PD-1⁺) compartment between effusion and blood, suggesting an enrichment of antigen specific clonotypes in the effusion, with potential as an immunological response biomarker.

Diagnostic accuracy of BRCA1-associated protein 1 in malignant mesothelioma: a meta-analysis

Background

Conventional measurements are not always helpful in the diagnosis of malignant mesothelioma (MM). Increasing studies indicate that loss of BRCA1–associated protein 1 (BAP1) detected by immunohistochemistry (IHC) is a useful diagnostic marker for MM. In this meta-analysis, we investigated the diagnostic accuracy of BAP1 in MM.

Results

In total, 12 eligible studies with a total of 1824 patients were selected. Results indicated that loss of BAP1 sustained a pooled sensitivity of 0.56 (95% CI, 0.50–0.62), specificity of 1.00 (95% CI, 0.95–1.00), PLR of 548.82 (95% CI, 11.31–2.7 × 104), NLR of 0.44 (95% CI, 0.39–0.50), DOR of 1247.78 (95% CI, 25.08 −6.2 × 104) in discriminating MM from non-MM. The AUC of 0.72, reflecting the SROC, indicated moderate diagnostic accuracy. Subgroup analysis showed that BAP1 detection in histological specimens owned the higher diagnostic performance than cytological ones. In addition, BAP1 showed superior diagnostic accuracy in epithelioid MM than biphasic or sarcomatoid MM.

Materials and Methods

PubMed, Embase and the Cochrane Library and reference lists of related articles were searched, and studies that evaluated the utility of BAP1 in MM were included. Data from eligible studies were pooled to estimate sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR). Summary receiver operating curves (SROC) was applied to estimate overall diagnostic accuracy.

Conclusions

Current meta-analysis indicates that detection of BAP1 by IHC is a useful diagnostic marker for MM. Loss of BAP1 almost provides confirming diagnosis for MM, while positive staining for BAP1 is not enough to exclude non-MM.

Pseudo-tumor mimicking indwelling pleural catheter tract metastasis in mesothelioma

Patients with malignant mesothelioma are known to be at risk of developing needle tract metastasis from seeding of malignant cells at the pleural intervention site. Histologic confirmation of needle tract metastases is seldom sought. The diagnosis and management (often radiotherapy) are almost always based on clinical judgment of new subcutaneous lesions at prior pleural puncture sites in mesothelioma patients. We report 2 patients with mesothelioma who developed new subcutaneous nodules at their indwelling pleural catheter insertion site, mimicking tract metastases. Biopsies of both lesions revealed benign etiologies and both resolved without requiring irradiation. These cases remind clinicians that new subcutaneous lesions can be benign even when arising at pleural puncture sites of malignant pleural mesothelioma patients. Percutaneous biopsy can clarify the diagnosis in suitable cases.

Persistent lung expansion after pleural talc poudrage in non-surgically resected malignant pleural mesothelioma

BACKGROUND

To investigate the prognostic effect of persistent lung expansion after pleural talcage and other variables in non-surgically resected malignant pleural mesothelioma (MPM) patients.

METHODS

All consecutive patients submitted to video-assisted thoracoscopic (VAT) pleurodesis by talc poudrage for MPM between 2006 and 2011 were studied. The following parameters were prospectively recorded: age; sex; smoking history; asbestos exposure; C-reactive protein (CRP) levels; platelet (PLT) count; Eastern Cooperative Oncology Group performance status (ECOG PS); histologic subtype; clinical stage (cStage); chemotherapy; pleural fluid volume; and persistence of lung expansion at 3 months follow-up. Survival was assessed in June 2013.

RESULTS

A total of 172 patients were considered; 146 of 172 patients demonstrated a complete lung expansion at discharge, whereas only 85 of 172 patients had persistent expanded lung on the affected side at the 3-month follow-up chest x-ray. Median survival was 11.5 months (95% confidence interval [CI], 10% to 14%) and 2-year disease-specific survival was 13% (95% CI, 7% to 24%) for the entire cohort. Multivariate analysis showed that non-epithelioid histology (hazard ratio [HR], 2.81; 95% CI, 1.82% to 5.09%), pleural fluid recurrence (HR 2.54; 95% CI, 1.73% to 4.40%), cStage greater than II (HR 2.36; 95% CI, 1.50% to 4.32%), ECOG PS greater than 1 (HR 2.19; 95% CI, 1.26% to 4.23%), CRP greater than 5 mg/L (HR 2.01; 95% CI, 1.18% to 4.12%), and PLT count greater than 400,000 (HR 1.76; 95% CI 1.14% to 3.92%) were independent predictors of poor prognosis.

CONCLUSIONS

Persistent lung expansion after pleural talc poudrage and absence of fluid recurrence is demonstrated to be a stronger factor in predicting survival rather than clinical stage and other clinical variables in not surgically resected MPM patients.

Protocol of the Australasian Malignant Pleural Effusion (AMPLE) trial: a multicentre randomised study comparing indwelling pleural catheter versus talc pleurodesis

INTRODUCTION

Malignant pleural effusion can complicate most cancers. It causes breathlessness and requires hospitalisation for invasive pleural drainages. Malignant effusions often herald advanced cancers and limited prognosis. Minimising time spent in hospital is of high priority to patients and their families. Various treatment strategies exist for the management of malignant effusions, though there is no consensus governing the best choice. Talc pleurodesis is the conventional management but requires hospitalisation (and substantial healthcare resources), can cause significant side effects, and has a suboptimal success rate. Indwelling pleural catheters (IPCs) allow ambulatory fluid drainage without hospitalisation, and are increasingly employed for management of malignant effusions. Previous studies have only investigated the length of hospital care immediately related to IPC insertion. Whether IPC management reduces time spent in hospital in the patients' remaining lifespan is unknown. A strategy of malignant effusion management that reduces hospital admission days will allow patients to spend more time outside hospital, reduce costs and save healthcare resources.

METHODS AND ANALYSIS

The Australasian Malignant Pleural Effusion (AMPLE) trial is a multicentred, randomised trial designed to compare IPC with talc pleurodesis for the management of malignant pleural effusion. This study will randomise 146 adults with malignant pleural effusions (1:1) to IPC management or talc slurry pleurodesis. The primary end point is the total number of days spent in hospital (for any admissions) from treatment procedure to death or end of study follow-up. Secondary end points include hospital days specific to pleural effusion management, adverse events, self-reported symptom and quality-of-life scores.

ETHICS AND DISSEMINATION

The Sir Charles Gairdner Group Human Research Ethics Committee has approved the study as have the ethics boards of all the participating hospitals. The trial results will be published in peer-reviewed journals and presented at scientific conferences.

TRIAL REGISTRATION NUMBERS

Australia New Zealand Clinical Trials Registry-ACTRN12611000567921; National Institutes of Health-NCT02045121.

Malignant pleural mesothelioma: current and future perspectives

Mesothelioma still remains an occupational related cancer with severe outcome. It is usually diagnosed at advanced stage since it does not demonstrate early symptoms. Several efforts have been made towards removing all materials inducing mesothelioma in the work setting and new work protection measures have been applied. Although we have new targeted treatments and radical surgery as arrows in the quiver, the type of mesothelioma and early diagnosis still remain the best treatment approach. Novel treatment modalities have been explored and several others are already on the way. In the current review we will present current data for mesothelioma and future perspectives.

Identification of pregnancy-associated plasma protein A as a migration-promoting gene in malignant pleural mesothelioma cells: a potential therapeutic target

Despite recent advances in treatment, malignant pleural mesothelioma (MPM) remains a deadly disease. Targeted therapy generated broad interests and is highly expected for the treatment of MPM, yet promising preclinical results have not been translated into substantial clinical benefits for the patients. In this study, we tried to identify the genes which play functional roles in cell migration as well as to test whether they can be used as novel targets for molecular targeted therapy for MPM in preclinical model. In our study, pregnancy-associated plasma protein A (PAPPA) was identified as a gene whose expression level is correlated with MPM cell migration by correlation analysis combining MPM cell migration ability and their gene expression profiles. Highly migratory cells were selected from MPM cell lines, MSTO-211H, NCI-H290 and EHMES-1 in vitro and up-regulation of PAPPA in these cells were confirmed. In vitro, PAPPA was demonstrated to stimulate the MPM cell migration via cleavage of insulin-like growth factor-binding protein-4 and subsequent release of IGF-1. Gene silencing of PAPPA in MPM cells led to reduced migration, invasion and proliferation. Furthermore, PAPPA shRNA transfected NCI-H290 when orthotopically inoculated into pleural cavity of severe combined immunodeficiency recipient mice, failed to develop tumors and produce bloody pleural effusion as control shRNA transfected cells did. Our study suggests that PAPPA plays a functional role in promoting MPM cell migration and it might serve as a potential therapeutic target for the treatment of MPM.

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.

Management of malignant pleural effusions: questions that need answers

PURPOSE OF REVIEW

Malignant pleural effusion (MPE) is common. However, regardless of the differences between patients, their underlying cancer type, and pleural fluid characteristics, management options are often limited. These have not advanced significantly over the last 80 years since pleurodesis was first described. Correspondingly, patient-related outcome measures have been neglected. The evidence (or lack of) behind the current treatment recommendations is reviewed and key research questions are described.

RECENT FINDINGS

Talc continues to be the most effective sclerosant available for pleurodesis in MPE. A recent randomized controlled trial comparing talc pleurodesis and indwelling pleural catheter insertion as first-line therapy suggests these approaches are equally effective, and utilized a patient-based symptom score as the primary outcome. The need to acknowledge the advances in translational medicine and oncological therapies to measure patient-related trial outcomes and to target pleural fluid formation in MPE is discussed.

SUMMARY

Pulmonologists should be aware of the staggering lack of progress in the evidence that supports the current 'recommended' management of MPE. The need for a re-think about MPE management with a focus on alternative therapeutic targets and treatment objectives should be appreciated, in order to optimize future patient care.

Diagnostic values of soluble mesothelin-related peptides for malignant pleural mesothelioma: updated meta-analysis

OBJECTIVE

Although the values of soluble mesothelin-related peptides (SMRPs), including mesothelin and megakaryocyte potentiating factor, in serum and/or pleural fluid for diagnosing malignant pleural mesothelioma (MPM) have been extensively studied, the exact diagnostic accuracy of these SMRPs remains controversial. The purpose of the present meta-analysis is to update the overall diagnostic accuracy of SMRPs in serum and, furthermore, to establish diagnostic accuracy of SMRPs in pleural fluid for MPM.

DESIGN

Systematic review and meta-analysis.

METHODS

A total of 30 articles of diagnostic studies were included in the current meta-analysis. Sensitivity, specificity and other measures of accuracy of SMRPs in serum and pleural fluid for the diagnosis of MPM were pooled using random effects models. Summary receiver operating characteristic curves were used to summarise overall test performance.

RESULTS

The summary estimates of sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic OR were 0.61, 0.87, 5.71, 0.43 and 14.43, respectively, for serum and 0.79, 0.85, 4.78, 0.30 and 19.50, respectively, for pleural fluid. It was also found that megakaryocyte potentiating factor in serum had a superior diagnostic accuracy compared with mesothelin for MPM.

CONCLUSIONS

SMRPs in both serum and pleural fluid are helpful markers for diagnosing MPM with similar diagnostic accuracy. The negative results of SMRP determinations are not sufficient to exclude non-MPM, and the positive test results indicate that further invasive diagnostic steps might be necessary for the diagnosis of MPM.

Comparison of the diagnostic accuracy of the MSLN gene products, mesothelin and megakaryocyte potentiating factor, as biomarkers for mesothelioma in pleural effusions and serum

The MSLN gene products, soluble mesothelin and megakaryocyte potentiating factor (MPF), are being investigated as biomarkers for the asbestos-related cancer malignant mesothelioma (MM). Pleural fluid biomarkers of MM can be elevated when serum levels remain normal. The aim of this study was to determine if this was true for MPF and to compare levels of mesothelin. Biomarker concentrations were compared in 66 MM patients, 39 patients with other malignancies, 37 with benign disease, 18 asbestos-exposed healthy individuals, and 53 patients with chronic kidney disease. In pleural effusions, MPF and soluble mesothelin concentrations were both significantly elevated in MM patients relative to controls. No significant difference between the area under the receiver operator curve (AUC) for MPF (0.945 ± 0.02) and mesothelin (0.928 ± 0.03) when distinguishing MM from all other causes of effusion was observed. MPF and mesothelin serum concentrations were highly correlated and of equivalent diagnostic accuracy with AUCs of 0.813 ± 0.04 and 0.829 ± 0.03, respectively. Serum levels of both markers increased with decreasing kidney function. In conclusion, MPF is elevated in the pleural effusions of MM patients similar to that of mesothelin. Mesothelin and MPF convey equivalent diagnostic information for distinguishing MM from other diseases in pleural effusions as well as serum.

Preclinical demonstration of synergistic Active Nutrients/Drug (AND) combination as a potential treatment for malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a poor prognosis disease lacking adequate therapy. We have previously shown that ascorbic acid administration is toxic to MPM cells. Here we evaluated a new combined therapy consisting of ascorbate/epigallocatechin-3-gallate/gemcitabine mixture (called AND, for Active Nutrients/Drug). In vitro effects of AND therapy on various MPM cell lines revealed a synergistic cytotoxic mechanism. In vivo experiments on a xenograft mouse model for MPM, obtained by REN cells injection in immunocompromised mice, showed that AND strongly reduced the size of primary tumor as well as the number and size of metastases, and prevented abdominal hemorrhage. Kaplan Meier curves and the log-rank test indicated a marked increase in the survival of AND-treated animals. Histochemical analysis of dissected tumors showed that AND induced a shift from cell proliferation to apoptosis in cancer cells. Lysates of tumors from AND-treated mice, analyzed with an antibody array, revealed decreased TIMP-1 and -2 expressions and no effects on angiogenesis regulating factors. Multiplex analysis for signaling protein phosphorylation exhibited inactivation of cell proliferation pathways. The complex of data showed that the AND treatment is synergistic in vitro on MPM cells, and blocks in vivo tumor progression and metastasization in REN-based xenografts. Hence, the AND combination is proposed as a new treatment for MPM.

Pleurodesis outcome in malignant pleural mesothelioma

Few data exist on the pleurodesis outcome in patients with malignant pleural mesothelioma (MPM). A retrospective review of the Western Australian Mesothelioma Registry over 5 years revealed 390 evaluable patients. Only a subset of patients (42.3%) underwent pleurodesis, surgically (n=78) or by bedside instillation of sclerosants (n=87). Surgical pleurodesis showed no advantages over bedside pleurodesis in efficacy (32% vs 31% failures requiring further drainage, p=0.98), patient survival (p=0.52) or total time spent in hospital from procedure till death (p=0.36). No clinical, biochemical or radiographic parameters tested adequately predict pleurodesis outcome.

Nanoprobes for hybrid SPECT/MR molecular imaging

Hybrid imaging techniques provide enhanced visualization of biological targets by synergistically combining multiple imaging modalities, thereby providing information on specific aspects of structure and function, which is difficult to obtain by a single imaging modality. Advances in the field of hybrid imaging have resulted in the recent approval of PET/magnetic resonance (MR) imaging by the US FDA for clinical use in the USA and Europe. Single-photon emission computed tomography (SPECT)/MR imaging is another evolving hybrid imaging modality with distinct advantages. Recently reported progress in the development of a SPECT/MR imaging hybrid scanner provides a cue towards the need for multimodal SPECT/MR imaging nanoprobes to take full advantage of a scanner’s simultaneous imaging capability. In this review, we present some of the latest developments in the domain of SPECT/MR hybrid imaging, particularly focusing on multimodal nanoprobes.

Soluble mesothelin-related Peptide and osteopontin as markers of response in malignant mesothelioma

PURPOSE

In malignant mesothelioma (MM), radiologic assessment of disease status is difficult. Both soluble mesothelin-related peptide (SMRP) and osteopontin (OP) have utility in distinguishing MM from benign pleural disease. We evaluated whether SMRP and OP also correlated with the disease course of MM.

PATIENTS AND METHODS

Serial plasma samples from patients with MM were prospectively collected, and SMRP and OP levels were measured. Radiologic tests across time periods showing disease progression, stability, or shrinkage were compared with corresponding changes in SMRP/OP levels.

RESULTS

From 41 patients, 165 samples were collected (range, 2 to 10; median 4). At study entry, 37 of 41 patients had measurable disease, of whom 92% (34 of 37) had elevated baseline SMRP levels; four of 41 patients had no evidence of recurrence and each had normal baseline SMRP levels. In 21 patients receiving systemic therapy, percentage change in SMRP more than 10% correlated with the radiologic assessment by a trained thoracic radiologist (P < .001), by formal Response Evaluation Criteria in Solid Tumors (RECIST; P = .008), or by modified RECIST (P < .001). All seven patients who underwent surgical resection with negative margins had elevated preoperative SMRP levels that fell to normal postoperatively. Rising SMRP was observed in all patients with radiologic disease progression. No associations were found with OP.

CONCLUSION

Percentage changes in SMRP levels, but not changes in OP levels, are a potentially useful marker of disease course. These findings should be validated prospectively for a role as an objective adjunctive measure of disease course in both clinical trials and clinical practice.

Respiratory chest pain: diagnosis and treatment

Chest pain from respiratory causes is a common complaint and may indicate the presence of a serious or even life-threatening pathologic condition. Most chest pains are the result of irritation or inflammation of the parietal pleura, as the visceral pleura is insensate, although pain may arise from direct malignant invasion or trauma to the chest wall. Rapid recognition with appropriate understanding of the anatomy and physiology of chest pain from respiratory causes is vital to ensure timely and appropriate therapy.

In vitro and in vivo characterization of highly purified human mesothelioma derived cells

BACKGROUND

Malignant pleural mesothelioma is a rare disease known to be resistant to conventional therapies. A better understanding of mesothelioma biology may provide the rationale for new therapeutic strategies. In this regard, tumor cell lines development has been an important tool to study the biological properties of many tumors. However all the cell lines established so far were grown in medium containing at least 10% serum, and it has been shown that primary cell lines cultured under these conditions lose their ability to differentiate, acquire gene expression profiles that differ from that of tissue specific stem cells or the primary tumor they derive from, and in some cases are neither clonogenic nor tumorigenic. Our work was aimed to establish from fresh human pleural mesothelioma samples cell cultures maintaining tumorigenic properties.

METHODS

The primary cell cultures, obtained from four human pleural mesotheliomas, were expanded in vitro in a low serum proliferation-permissive medium and the expression of different markers as well as the tumorigenicity in immunodeficient mice was evaluated.

RESULTS

The established mesothelioma cell cultures are able to engraft, after pseudo orthotopic intraperitoneal transplantation, in immunodeficient mouse and maintain this ability to after serial transplantation. Our cell cultures were strongly positive for CD46, CD47, CD56 and CD63 and were also strongly positive for some markers never described before in mesothelioma cell lines, including CD55, CD90 and CD99. By real time PCR we found that our cell lines expressed high mRNA levels of typical mesothelioma markers as mesothelin (MSLN) and calretinin (CALB2), and of BMI-1, a stemness marker, and DKK1, a potent Wingless [WNT] inhibitor.

CONCLUSIONS

These cell cultures may provide a valuable in vitro and in vivo model to investigate mesothelioma biology. The identification of new mesothelioma markers may be useful for diagnosis and/or prognosis of this neoplasia as well as for isolation of mesothelioma tumor initiating cells.

Medical thoracoscopy

PURPOSE OF REVIEW

The technique and clinical applications of medical thoracoscopy have substantially evolved in the last few decades. The recent development of a semirigid thoracoscope, which is handled similarly to a bronchoscope, has made this procedure more attractive to pulmonologists. We will review the latest data on clinical applications, recently developed techniques, and safety of medical thoracoscopy, focusing mainly on its role in thoracic malignancies.

RECENT FINDINGS

Recent data confirm the high diagnostic yield of medical thoracoscopy - both with rigid and semirigid instruments - in detecting pleural metastases and determining the origin of pleural effusions. The degree of pleural adhesions found during thoracoscopy has been proposed by some authors as a prognostic factor for survival in patients with malignant pleural effusion. A large prospective multicenter study has established the safety of talc poudrage with large-particle talc, showing no cases of acute respiratory distress syndrome.

SUMMARY

Medical thoracoscopy is an excellent tool to establish diagnosis in patients with exudative pleural effusion of unclear origin. It is highly valuable in clarifying the origin of pleural effusions in patients with lung cancer, as the presence of a malignant pleural effusion is associated with poor survival and precludes the possibility of treatment with curative intention. Pleurodesis with talc poudrage is efficacious and well tolerated, especially with the use of large-particle talc.

Clinical impact and reliability of pleural fluid mesothelin in undiagnosed pleural effusions

RATIONALE

Serum mesothelin is a new biomarker for the diagnosis of mesothelioma. Patients with mesothelioma commonly present with pleural effusions. To define the clinical utility of mesothelin quantification in pleural fluid, we assessed its additional value over pleural fluid cytology and its short-term reproducibility and reliability after pleural inflammatory processes, including pleurodesis.

OBJECTIVES

To assess the diagnostic role of pleural fluid mesothelin and the effect of common clinical factors that may influence measurement accuracy.

METHODS

Mesothelin was quantified in 424 pleural fluid and 64 serum samples by ELISA. Fluid was collected prospectively from 167 patients who presented with pleural effusions for investigation. Serial pleural fluid samples were obtained from patients (n = 33) requiring repeated drainage. Mesothelin levels were also measured in patients (n = 32) prepleurodesis and postpleurodesis.

MEASUREMENTS AND MAIN RESULTS

Pleural fluid mesothelin concentrations were significantly higher in patients with mesothelioma (n = 24) relative to those with metastatic carcinomas (n = 67) and benign effusions (n = 75): median (interquartile range, 25th-75th percentile) = 40.3 (18.3-68.1) versus 6.1 (1.5-13.2) versus 3.7 (0.0-12.4) nM, respectively, P < 0.0001. Mesothelin measurement was superior to cytological examination in the diagnosis and exclusion of mesothelioma (sensitivity, 71 vs. 35%; specificity, 89 vs. 100%; negative predictive value, 95 vs. 82%, respectively). In patients with "suspicious" cytology, pleural fluid mesothelin was 100% specific for mesothelioma, and in cytology-negative effusions (n = 105) offered a negative predictive value of 94%. Intraindividual reproducibility of pleural fluid mesothelin was excellent: mean (+/-SD) variation, -0.15 (+/-8.41) nM in samples collected within 7 days from patients with mesothelioma. Measurements remained reliable after pleurodesis and were not affected by the presence of bacteria.

CONCLUSIONS

Pleural fluid mesothelin provides additional diagnostic value relative to cytological examination. Mesothelin measurements are reproducible and not affected by inflammatory pleural processes.

Intradural pleural malignant mesothelioma

Pleural malignant mesothelioma is a rare tumour of the pleural epithelium, which progresses by infiltration into the lung parenchyma, the chest wall, and the mediastinum. Haematogenous spreading may occur in the late stages of the disease. Spinal involvement is exceptional and usually occurs in the vertebral body or epidural space, and intradural location of a mesothelioma is even more uncommon. In this article, a MEDLINE literature review on intradural mesothelioma was conducted and four intradural mesothelioma cases in the English literature were retrieved: one in the intradural extramedullary location and three with intramedullary growth. Additionally, we report a 50-year-old patient with a pleural malignant mesothelioma that spreads across the dura into the spinal cord at T5.

Biomarkers for mesothelioma

PURPOSE OF REVIEW

Mesothelioma is an incurable cancer and its global incidence continues to increase. There has been strong interest in the search for a biomarker that would be of value for the diagnosis, prognosis and disease monitoring of mesothelioma. Large series evaluating the use of novel candidate markers have recently been published.

RECENT FINDINGS

To date, global gene profiling studies have failed to find a molecule that reliably captures all subtypes of mesothelioma, and differentiates it from benign pathologies and metastatic carcinomas. Soluble mesothelin-related peptide (SMRP), osteopontin and megakaryocyte potentiating factor have been assessed as markers. SMRP testing is clinically available and provides reasonable diagnostic sensitivity and specificity when applied to serum or pleural fluid. Elevated SMRP levels can occur in metastatic, especially ovarian and pancreatic, adenocarcinomas. False negatives are common with sarcomatoid mesothelioma. SMRP levels may reflect tumor load and disease progression. The role of SMRP in predicting mesothelioma development in subjects exposed to asbestos has raised interest. Osteopontin lacks specificity as a diagnostic marker for mesothelioma but may have value in disease monitoring.

SUMMARY

The proposed markers have insufficient accuracy to replace cytohistology as the gold standard for diagnosis for mesothelioma. Elevated SMRP levels raise suspicion of mesothelioma although negative values do not exclude disease. Its role in disease monitoring in patients and in predicting disease development in at-risk individuals warrant further study.

Management options for malignant pleural mesothelioma: clinical and cost considerations

Malignant pleural mesothelioma (MPM) is a resistant form of lung cancer that is often related to prior asbestos exposure. While surgical resection and radiotherapy techniques have been refined in recent years, neither has been proven to significantly extend patient survival compared with untreated controls. Until the release of pemetrexed in 2004, even combination chemotherapy regimens often resulted in a response rate of <20%. A recent phase III trial documented a 41.3% response rate for cisplatin plus pemetrexed. In the future, new multimodality regimens featuring novel targeted therapies directed against molecular targets, such as the vascular endothelial growth factor, hold the greatest promise for improved outcomes in MPM. The standard radiographic assessment of response to MPM therapy remains a poor surrogate for clinically relevant endpoints such as median survival. Furthermore, it is not currently known whether aggressive multimodality treatment for MPM will improve survival or quality of life above and beyond symptomatic care. Ongoing clinical trials are comparing chemotherapy and surgery with supportive care in an effort to define the role of different therapies in MPM. MPM treatment is a costly public health issue; after efficacy is proven, additional studies are needed to measure the cost effectiveness of MPM treatment regimens.

Four-Modality Therapy in Malignant Pleural Mesothelioma: A Phase II Study

BACKGROUND

Treatment approaches in malignant pleural mesothelioma (MPM) patients range from mere palliation to aggressive anticancer therapy, and there is currently no consensus on the optimal therapeutic strategy. In 1999, we began a phase II study to investigate four-modality treatment of advanced stage MPM.

METHODS

From 1999 to 2004, 49 patients with International Mesothelioma Interest Group stage II-III MPM underwent four-modality treatment with intrapleural preoperative interleukin-2 (18 x 10(6) UI/day for 3 days), pleurectomy/decortication, intrapleural postoperative epidoxorubicin (25 mg/m2 for 3 days), interleukin-2 (18 x 10(6) UI/day for 3 days), adjuvant radiotherapy (30 Gy), systemic chemotherapy (cisplatin 80 mg/m2 day 1, gemcitabine 1250 mg/m2 days 1 and 8 for up to six courses) and long-term subcutaneous interleukin-2 (3 x 10(6) UI/day on 3 days per week).

RESULTS

Patients included 41 men and eight women with a median age of 61 years (range, 41-77). All patients were diagnosed with MPM by thoracoscopy before inclusion. There was no postoperative mortality. Postoperative morbidity included bleeding (n = 1) and arrhythmias (n = 3). After a median follow-up of 59 months (range, 14-81), 13 patients are still alive and the median actuarial survival is 26 months (31 and 21 months for stages II and III, respectively). The 2- and 5-year actuarial survival rates were 60.2% and 23.3%, respectively. Baseline Eastern Cooperative Oncology Group performance status significantly influenced survival time (p = 0.02).

CONCLUSION

The four-modality treatment that we adopted for advanced-stage MPM was feasible, well tolerated by most of the patients, and produced a favorable median survival. This treatment approach warrants further investigation.