Management of malignant pleural mesothelioma: a critical review

Thiolate DNAzymes on Gold Nanoparticles for Isothermal Amplification and Detection of Mesothelioma-derived Exosomal PD-L1 mRNA

Catalytic DNAzymes have been used for isothermal amplification and rapid detection of nucleic acids, holding the potential for point-of-care testing applications. However, when Subzymes (universal substrate and DNAzyme) are tethered to the polystyrene magnetic microparticles via biotin-streptavidin bonds, the residual free Subzymes are often detached from the microparticle surface, which causes a significant degree of false positives. Here, we attached dithiol-modified Subzyme to gold nanoparticle and improved the limit of detection (LoD) by 200 times compared to that using magnetic microparticles. As a proof of concept, we applied our new method for the detection of exosomal programed cell-death ligand 1 (PD-L1) RNA. As the classical immune checkpoint, molecule PD-L1, found in small extracellular vesicles (sEVs, traditionally called exosomes), can reflect the antitumor immune response for predicting immunotherapy response. We achieved the LoD as low as 50 fM in detecting both the RNA homologous to the PD-L1 gene and exosomal PD-L1 RNAs extracted from epithelioid and nonepithelioid subtypes of mesothelioma cell lines, which only takes 8 min of reaction time. As the first application of isothermal DNAzymes for detecting exosomal PD-L1 RNA, this work suggests new point-of-care testing potentials toward clinical translations.

Cytoreductive Surgical Treatment of Pleural Mesothelioma in a Porcine Model Using Magnetic-Resonance-Guided Focused Ultrasound Surgery (MRgFUS) and Radiofrequency Ablation (RFA)

A combination of surgery and chemotherapy is the most effective treatment available for Malignant Pleural Mesothelioma (MPM). However, both cause significant collateral damage and cannot eliminate residual microscopic disease. This investigation aimed to compare and determine the feasibility of utilizing Radiofrequency Ablation (RFA) and Magnetic-Resonance-guided Focused Ultrasound Surgery (MRgFUS) as alternative treatments for MPM. A large animal tumor model was developed in 13 Yorkshire female pigs using the MSTO211H cell line. Two pigs were initially used to determine the cyclosporine dose required for immunosuppression and tumor development. Subsequently, 11 other pigs underwent tumor development. Of these 11, 2 died during cell inoculation. Small tumor masses and adhesions were present in the other 9, indicating mesothelioma development. Five pigs then received RFA treatment, and 4 pigs received MRgFUS treatment. Tumor model development and effect of the two treatments were examined using MRI and by necropsy. RFA and MRgFUS both successfully ablated approximately the same sized area in the same treatment time. This study demonstrates that RFA and MRgFUS are feasible for tumor debulking, and while MRgFUS requires more pretreatment planning compared to RFA, MRgFUS is a completely noninvasive procedure.

Malignant Pleural Effusions-A Review of Current Guidelines and Practices

Malignant pleural effusion (MPE) occurs in 15% of all cancer patients and usually portends poor prognosis while also serving to limit the patient's quality of life. Palliation of symptoms has been the goal for the management of these effusions while keeping the patient's hospital stay to a minimum. Traditionally, this has been achieved by chest tube drainage followed by the instillation of sclerosing agents, such as talc, in the pleural space. A recent increase in evidence for the effectiveness and convenience of indwelling pleural catheters has changed the management of MPE, which is reflected in the guidelines released by the American Thoracic Society as well their European Counterpart (ERS/BTS). In this article, we aim to review the current management practices and guidelines for MPE.

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.

Epirubicin and Gemcitabine as First-Line Treatment in Malignant Pleural Mesothelioma

Malignant pleural mesothelioma represents a rare disease, for which chemotherapy actually remains unsatisfactory. From August 1998 to November 2001, 28 chemo-radio-immunonaive patients were consecutively enrolled in the trial: 22/6 males/females; median age 63 years (range, 45-79); median ECOG PS 1 (range, 0-2). They were treated with epirubicin (100 mg/m2 iv on day 1) plus gemcitabine (1000 mg/m2 iv on days 1 and 8) every 4 weeks for 6 cycles. Patients who responded to chemotherapy (n = 6) were subsequently treated with interleukin-2 (4,500,000 IU) subcutaneously every other day, until progression. A total of 124 epirubicin-gemcitabine cycles were administered (median, 6/patient; range, 2-6). Twenty-six patients were evaluated for toxicity. According to WHO criteria, we observed grade III-IV hematological and gastrointestinal toxicity respectively in 3 patients (11%) and 1 patient (3%). No red cell transfusions were required and no toxic deaths occurred. Two patients (8%) could not be evaluated for response (no therapy performed). According to WHO criteria, the final responses were: partial in 4 patients (14%), stable disease in 19 patients (69%), and progression in 3 patients (10%). In 26 patients, the median survival was 55 weeks (range, 7-222) and median time to progression 30 weeks (range, 4-156). At the time of this writing, no patient is alive. The 1-year survival was 32%, 2-year survival 11%, and 4% at 3 and 4 years. All patients were at stage III, and time to progression was 58 weeks and survival 63.5 weeks, without any toxicity. This multi-center phase II clinical trial showed that epirubicin plus gemcitabine, as a first-line treatment in malignant pleural mesothelioma, has promising activity with a good tolerability profile and symptom palliation. The role of interleukin-2 in maintenance therapy for malignant pleural mesothelioma is encouraging and requires further study.

Pleural Mesothelioma with No Asbestos Exposure: A Case Report

Malignant Pleural Mesothelioma (MPM) is the primary malignant tumour of the pleura. It is highly aggressive and linked to the exposure to asbestos fibers. The prognosis of this cancer is bad with a median of survival around 12 months. The diagnosis of pleural mesothelioma is often done at an advanced stage of the disease because of the lack of specific clinical and radiological signs differentiating it from any malignant pleural effusion. The absence of an explicit asbestos exposure is another diagnosis problem. We report the case of a 60-year-old patient without any prior exposure to asbestos who presented for pleural effusion and a nodular thickening of the pleura on the CT scan. The diagnosis of MPM was confirmed after pathology study of the biopsies obtained by video assisted thoracoscopy.

Diagnosis and management options in malignant pleural effusions

Malignant pleural effusion (MPE) denotes an advanced malignant disease process. Most of the MPE are metastatic involvement of the pleura from primary malignancy at lung, breast, and other body sites apart from lymphomas. The diagnosis of MPE has been traditionally made on cytological examination of pleural fluid and/or histological examination of pleural biopsy tissue that still remains the initial approach in these cases. There has been tremendous advancement in the diagnosis of MPE now a day with techniques i.e. characteristic Ultrasound and computed tomography features, image guided biopsies, fluorodeoxyglucose-positron emission tomography imaging, thoracoscopy with direct biopsy under vision, tumor marker studies and immunocytochemical analysis etc., that have made possible an early diagnosis of MPE. The management of MPE still remains a challenge to pulmonologist and oncologist. Despite having various modalities with better tolerance such as pleurodesis and indwelling pleural catheters etc., for long-term control, all the management approaches remain palliative to improve the quality of life and reduce symptoms. While choosing an appropriate management intervention, one should consider the clinical status of the patient, life expectancy, overall cost, availability and comparative institutional outcomes, etc.

Modern management of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a deadly disease that produces a significant worldwide health care burden. The majority of cases are associated with prior asbestos exposure, but recent studies have identified a possible genetic predisposition in a minority of patients. Historically, obtaining a pathologic diagnosis of MPM was challenging, but with current pathological techniques, a secure diagnosis is possible in the majority of patients. Curative therapy for MPM remains elusive, and the primary treatment option for fit patients is platinum-based chemotherapy. Encouraging recent reports suggest that there may be a benefit to the addition of bevacizumab to standard chemotherapy as well as with the use of immune checkpoint inhibitors in MPM. Selected patients may be considered for aggressive surgical approaches, but there is considerable controversy regarding the true benefit of surgery and multimodality therapy in this disease.

Surgical Management of Malignant Pleural Mesothelioma: An Update of Clinical Evidence

To investigate the surgical management of malignant pleural mesothelioma, 2 randomized controlled trials have been completed. We discuss the findings from these trials and the current evidence of various surgical techniques to treat this challenging disease.

Pleural effusion: diagnosis, treatment, and management

A pleural effusion is an excessive accumulation of fluid in the pleural space. It can pose a diagnostic dilemma to the treating physician because it may be related to disorders of the lung or pleura, or to a systemic disorder. Patients most commonly present with dyspnea, initially on exertion, predominantly dry cough, and pleuritic chest pain. To treat pleural effusion appropriately, it is important to determine its etiology. However, the etiology of pleural effusion remains unclear in nearly 20% of cases. Thoracocentesis should be performed for new and unexplained pleural effusions. Laboratory testing helps to distinguish pleural fluid transudate from an exudate. The diagnostic evaluation of pleural effusion includes chemical and microbiological studies, as well as cytological analysis, which can provide further information about the etiology of the disease process. Immunohistochemistry provides increased diagnostic accuracy. Transudative effusions are usually managed by treating the underlying medical disorder. However, a large, refractory pleural effusion, whether a transudate or exudate, must be drained to provide symptomatic relief. Management of exudative effusion depends on the underlying etiology of the effusion. Malignant effusions are usually drained to palliate symptoms and may require pleurodesis to prevent recurrence. Pleural biopsy is recommended for evaluation and exclusion of various etiologies, such as tuberculosis or malignant disease. Percutaneous closed pleural biopsy is easiest to perform, the least expensive, with minimal complications, and should be used routinely. Empyemas need to be treated with appropriate antibiotics and intercostal drainage. Surgery may be needed in selected cases where drainage procedure fails to produce improvement or to restore lung function and for closure of bronchopleural fistula.

OccIDEAS: An Innovative Tool to Assess Past Asbestos Exposure in the Australian Mesothelioma Registry

Malignant mesothelioma is an uncommon but rapidly fatal disease for which the principal aetiological agent is exposure to asbestos. Mesothelioma is of particular significance in Australia where asbestos use was very widespread from the 1950s until the 1980s. Exposure to asbestos includes occupational exposure associated with working with asbestos or in workplaces where asbestos is used and also 'take-home' exposure of family members of asbestos exposed workers. Asbestos exposure may also be non-occupational, occurring as a consequence of using asbestos products in non-occupational contexts and passive exposure is also possible, such as exposure to asbestos products in the built environment or proximity to an environmental source of exposure, for example an asbestos production plant. The extremely long latency period for this disease makes exposure assessment problematic in the context of a mesothelioma registry. OccIDEAS, a recently developed online tool for retrospective exposure assessment, has been adapted for use in the Australian Mesothelioma Registry (AMR) to enable systematic retrospective exposure assessment of consenting cases. Twelve occupational questionnaire modules and one non-occupational module have been developed for the AMR, which form the basis of structured interviews using OccIDEAS, which also stores collected data and provides a framework for generating metrics of exposure.

PET-guided dose escalation tomotherapy in malignant pleural mesothelioma

PURPOSE

To test the feasibility of salvage radiotherapy using PET-guided helical tomotherapy in patients with progressive malignant pleural mesothelioma (MPM).

PATIENTS AND METHODS

A group of 12 consecutive MPM patients was treated with 56 Gy/25 fractions to the planning target volume (PTV); FDG-PET/CT simulation was always performed to include all positive lymph nodes and MPM infiltrations. Subsequently, a second group of 12 consecutive patients was treated with the same dose to the whole pleura adding a simultaneous integrated boost of 62.5 Gy to the FDG-PET/CT positive areas (BTV).

RESULTS

Good dosimetric results were obtained in both groups. No grade 3 (RTOG/EORTC) acute or late toxicities were reported in the first group, while 3 cases of grade 3 late pneumonitis were registered in the second group: the duration of symptoms was 2-10 weeks. Median overall survival was 8 months (1.2-50.5 months) and 20 months (4.3-33.8 months) from the beginning of radiotherapy, for groups I and II, respectively (p=0.19). A significant impact on local relapse from radiotherapy was seen (median time to local relapse: 8 vs 17 months; 1-year local relapse-free rate: 16% vs 81%, p=0.003).

CONCLUSIONS

The results of this pilot study support the planning of a phase III study of combined sequential chemoradiotherapy with dose escalation to BTV in patients not able to undergo resection.

Malignant pleural mesothelioma: clinicopathologic and survival characteristic in a consecutive series of 40 patients

INTRODUCTION

Pleural malignant mesothelioma is an uncommon but extremely invasive tumor which originates from mesothelial cells and usually occurs after prolonged exposure to asbestos. Different types of surgical and oncological therapeutic methods have been used resulting in various outcomes. The aim of this study was to evaluate, clinicopathologically, 40 patients with pleural malignant mesothelioma and the main factors influencing their prognosis.

METHODS

In this study, 40 patients with a definitive diagnosis, who had been followed up for at least 3 years were studied according to these: epidemiologic factors, stage and pathological types, treatment method and complications, and by using factors that influence patients survival, we evaluated them statistically.

RESULTS

The M/F ratio was l3/1 with an average age of 55 years. Chest pain was the most common symptom. In 55% of patients, the lesions were localized in the left site and most were in Buchart stage I or II. The epithelial form was the most common pathological pattern (62.5%). 47.5% of patients only received radiotherapy and chemotherapy. Of patients who underwent decortication and pleurectomy with adjuvant therapy, extrapleural was performed in 20% of patients, and pneumonectomy, in 17.5%; and 15% refused any type of treatment. One patient died from the surgery. The most common surgical complication was wound infection. The average survival was 10.5 months, and the main factors influencing the survival were physiologic status, pathological form of disease, stage of disease and the pattern of pleural involvement.

CONCLUSION

Because of the low survival after multimodality invasive treatments in mesothelioma, aggressive therapeutic methods were recommended in patients with good physiological status and early clinical stage with a good pathology type.

Recent advances in the diagnosis and management of malignant pleural effusions

Malignant pleural effusions (MPEs) are an important complication for patients with intrathoracic and extrathoracic malignancies. Median survival after diagnosis of an MPE is 4 months. Patients can present with an MPE as a complication of far-advanced cancer or as the initial manifestation of an underlying malignancy. Common cancer types causing MPEs include lymphomas, mesotheliomas, and carcinomas of the breast, lung, gastrointestinal tract, and ovaries. However, almost all tumor types have been reported to cause MPEs. New imaging modalities assist the evaluation of patients with a suspected MPE; however, positive cytologic or tissue confirmation of malignant cells is necessary to establish a diagnosis. Even in the presence of known malignancy, up to 50% of pleural effusions are benign, underscoring the importance of a firm diagnosis to guide therapy. Rapidly evolving interventional and histopathologic techniques have improved the diagnostic yield of standard cytology and biopsy. Management of an MPE remains palliative; it is critical that the appropriate management approach is chosen on the basis of available expertise and the patient's clinical status. This review summarizes the pathogenesis, diagnosis, and management of MPE. Studies in the English language were identified by searching the MEDLINE database (1980-2007) using the search terms pleura, pleural, malignant, pleurodesis, and thoracoscopy.

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.

Accuracy and reproducibility of pleural effusion cytology

The increasing number of Malignant Mesothelioma (MM) cases that arrive for expert examinations to court for compensation reasons in subjects exposed to asbestos, in many instances rely exclusively on cytological smears of pleural effusion. We evaluated the accuracy and reproducibility of cytological pleural effusions, based on morphological criteria alone. Nine pathologists and eight residents from seven institutions in north-east Italy blindly examined 45 smears of MM (17), metastases (14) and benign effusions (14), in two rounds. Diagnoses had been confirmed by immunohistochemical and clinical follow-up, and eventually at autopsy. Diagnostic accuracy, interobserver and intraobserver agreement in the distinction of benign vs malignant cases, and in the differentiation of primary from metastatic malignancies, were evaluated. The distinction of benign from malignant smears resulted rather satisfactory (k=0.514), but markedly decreased in differentiation of MM from metastases (overall agreement: k=0.343), as well as when readings from residents were analyzed (k=0.132). Cytology is a useful and reliable tool in the identification of malignancies, but when the distinction of primary from metastatic tumors is addressed morphological criteria alone are not sufficient for a definite diagnosis of MM and the use of cell blocks, immunohistochemistry (IHC) and molecular ancillary techniques are recommended.

Induction chemotherapy, extrapleural pneumonectomy (EPP) and adjuvant hemi-thoracic radiation in malignant pleural mesothelioma (MPM): Feasibility and results

BACKGROUND

Trimodality therapy seems to be the best treatment for malignant pleural mesothelioma (MPM). A large experience served to evaluate the efficacy of surgery followed by adjuvant chemo-radiotherapy. Trimodality therapy results have led us to test induction chemotherapy followed by EPP and adjuvant radiotherapy in stages I-III of MPM. The aim of our study was to evaluate the feasibility of this protocol and to estimate survival.

METHODS

From 2000 to 2003, 21 patients with MPM (14 males and 7 females, median age 59 years) were enrolled in the prospective study. Induction chemotherapy consisted of Carboplatin (AUC 5mg/mL/min on Day 1) and Gemcitabine (1000mg/m(2) on Days 1, 8, 15) for three to four cycles. EPP was performed 3-5 weeks after induction therapy, while post-operative RT was given 4-6 weeks after operation.

RESULTS

Ten patients received three cycles of chemotherapy, 10 patients received four cycles and 1 patient had two cycles. Grades 3-4 haematological toxicity occurred in eight (38.1%) patients. Chemotherapy response rate was: complete 0%, partial 33.3% and stable disease 66.7%. Seventeen (80.9%) out of 21 patients underwent EPP with no intra or post-operative mortality with an overall major and minor morbidity rate at 52.4%. Median survival was 25.5 months, with an overall 1, 3 and 5-year survival rate of 71, 33 and 19%, respectively.

CONCLUSIONS

In MPM, the combined modality approach using the Carboplatin/Gemcitabine combination as induction chemotherapy is feasible, with good results in terms of survival and morbidity. Our results are similar to those of other studies using a heavier modality treatment.

Pathogenesis of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) results from neoplastic transformation of mesothelial cells. Past asbestos exposure represents the major risk factor for MPM, as the link between asbestos fibres and MPM has been largely proved by epidemiological and experimental studies. Asbestos fibres induce DNA and chromosome damage linked to oxidative stress following phagocytosis. Recently, simian virus 40 (SV40) has been implicated in the aetiology of MPM. The origin of human infection has been associated with SV40-contaminated polio vaccines, although to date, no epidemiological data supports this hypothesis. SV40 may act as a coactivator of asbestos in mesothelial oncogenesis. The transforming potency of SV40 results from the activity of two viral proteins, large T and small t antigens. SV40 infection stimulates production of growth factors elsewhere implicated in autocrine growth of mesothelioma cells and inactivates RASSF1, a gene silenced in MPM. Roles for ionising radiation, chemicals or genetic factors have also been suggested from the observation of sporadic MPM cases or animal studies. Genetic alterations in the tumour suppressor genes, P16/CDKN2A and neurofibromatosis 2 (NF2), are found both in human MPM and in asbestos-exposed Nf2-deficient mice. MPM is still of great international concern. Despite a ban on asbestos use in Western countries, the incidence of MPM is increasing, due to the long delay between asbestos exposure and diagnosis. Moreover, asbestos is still used in developing countries. The implication of other risk factors, especially SV40, supports a need for further research into MPM.

Expression of the secreted frizzled-related protein gene family is downregulated in human mesothelioma

Secreted frizzled-related proteins (sFRPs) comprise a family of five secreted glycoproteins that antagonize Wnt signaling. Aberrant activation and upregulation of the Wnt pathway is a key feature of many cancers. Thus, role of sFRP as a negative regulator of Wnt signaling may have important implications in tumorigenesis, and its downregulation has been correlated with human cancers. Recently, we reported Wnt signaling and dishevelled (Dvl) overexpression in malignant pleural mesothelioma (MM). Here, we report significant transcriptional downregulation of the SFRP gene family in MM primary tissues and cell lines as well as several other cancer cell lines (breast, lung, glioma, and cervical) compared to normal cells. One or more SFRPs were downregulated in approximately 85% (18 of 21) of primary MM tumor specimens compared to normal pleural tissue. Eight of the nine cancer cell lines we examined showed silencing of the SFRP family. Methylation-specific PCR (MSP) analysis showed that SFRP1, SFRP4, and SFRP5 gene promoters are frequently methylated in MM primary tissue (>80%). Furthermore, transfection of the SFRP gene construct into MM cell lines lacking SFRP expression resulted in apoptosis and growth suppression. Our results suggest that methylation silencing of SFRPs may be one of the important mechanisms of aberrant Wnt signaling activation in MM.

Gene expression profiles in human mesothelioma cell lines in response to interferon-γ treatment

Interferon-gamma (IFN-gamma) has been found to be antiproliferative and antitumoral in malignant mesothelioma (MM), but the MM cell response to IFN-gamma has not been fully characterized so far. We investigated gene expression profiles in human MM cell lines (HMCLs) exposed to IFN-gamma. Four HMCLs showing different sensitivities to the antiproliferative effect of IFN-gamma, two of them presenting a defect in the JAK/STAT signaling pathway, were treated with 500 IU/mL of IFN-gamma. Gene expression patterns were studied at 6 and 72 hours after exposure to the IFN-gamma, using a cDNA array technique. Six genes were studied with real-time reverse transcription-polymerase chain reaction. The gene expression profiles in response to IFN-gamma were shown to differ in different HMCLs. Numerous genes involved in cell proliferation and cell adhesion were regulated by IFN-gamma in JAK/STAT-deficient HMCLs. Genes possibly involved in regulation of cell proliferation included CDC2, PLK1, and IGFBP4, as well as several genes involved in cell-cell interactions and cell adhesion. The cDNA array technique revealed differences in expression pathways, especially those involved in cell growth, cell adhesion, and cell proliferation, between IFN-gamma-resistant and -sensitive MM cell lines. We found that the changes in gene expression profiles of HMCLs exposed to IFN-gamma were also related to features other than the antiproliferative response.

Experimental therapy of malignant mesothelioma: new perspectives from anti-angiogenic treatments

We reviewed the published literature of clinical studies in malignant mesothelioma (MM), including phase II as well as older single-agent and combination chemotherapy trials with more than 15 patients. While response rates exceeding 30% have been achieved with established cytotoxic drugs in MM therapy, novel chemotherapeutic agents and their combinations appear more promising. This applies especially to the anti-metabolites (i.e. pemetrexed) that produced response rates of up to 45% in combination with platinum compounds. Moreover, agents targeting novel proliferative and survival pathways in MM are developed to improve treatment outcomes. Here, we focused on the role of several angiogenic growth factors in MM biology and the data of MM-oriented studies on angiostatic agents tested in a phase I-II trial. It seems likely that no single treatment modality will be effective by itself. Studies that use combinations of the newer agents, including angiostatic drugs, with chemotherapy, should be conducted.

Preclinical evaluation of the nonsteroidal anti-inflammatory agent celecoxib on malignant mesothelioma chemoprevention

Malignant mesothelioma (MM) remains the most lethal pleural, peritoneal and pericardial cancer. Here, we characterize the effects of nonsteroidal anti-inflammatory agents (NSAIDs) on in vitro and in vivo experimental MM models. Unlike primary normal mesothelial cells, the selective cyclooxygenase (COX)-2 inhibitor celecoxib reduced the in vitro proliferation of several MM cells derived from previously untreated MM patients. Moreover, celecoxib significantly inhibited MM cell colony formation in soft agarose (63-78% at 5 x 10(-5) M; p < or = 0.05) and it elicited remarkable antitumor activity, leading to long-term survival in >37% of nude mice bearing intraperitoneal MM. Celecoxib was more efficient in inhibiting MM cell growth than acetylsalicylic acid (10(-6) M-10(-2) M), indometacin (10(-6) M-10(-2) M) and the COX-2 inhibitor NS-398 (10(-6) M-10(-4) M). Efficacy of these different compounds was not related to the amount of COX-2 protein levels present on MM cells. Celecoxib, in a dose- and time-dependent manner, induced MM cell apoptosis, which involved decreased Akt phosphorylation, loss of Bcl-2 and Survivin protein expression and caspase-3 activation. Furthermore, vascular endothelial growth factor (VEGF), an MM autocrine growth factor and Akt inducer, rescued celecoxib-induced apoptosis and Akt dephosphorylation. When the VEGF receptor (KDR/Flk-1) inhibitor, SU-1498, was used in combination with celecoxib, IC50 of celecoxib in vitro was reduced up to 65%. These data demonstrate that celecoxib may have antitumor properties in MM and provide a rationale for the therapeutic use of celecoxib in combination with a selective VEGF inhibitor.

Cross‐talk between vascular endothelial growth factor and semaphorin‐3A pathway in the regulation of normal and malignant mesothelial cell proliferation

Vascular endothelial growth factor (VEGF) and semaphorin-3A (Sema-3A) play important roles in the transduction of promitotic and antimitotic signals, respectively. Here, we report that these conflicting signals are integrated via negative feedback between VEGF and Sema-3A pathways in several primary normal, but not malignant, mesothelial cells. Unlike malignant mesothelial (MM) cells, in which VEGF induces cell proliferation, normal mesothelial (NM) cell growth was repressed by VEGF. Although both cell-types expressed an overlapping set of VEGF tyrosine-kinase receptors, only in NM cells VEGF exposure entails a p38 mitogen-activated protein kinase (MAPK)-dependent increased of Sema-3A production. Inhibition of p38 MAPK (by SB202190 and SB203580) or a dominant-negative mutant of Sema-3A receptor plexin-A1 reversed the inhibitory effects of VEGF in NM cells, increasing cyclin D1 synthesis and cell growth. Conversely, sustained activation of p38 MAPK by the p38 MAPK-activating kinases MKK3 and MKK6 or transfection with Sema-3A inhibited VEGF-induced cyclin D1 up-regulation and MM cell proliferation. Therefore, these results delineate a new role of Sema-3A in VEGF function mediated by p38 MAPK and suggest that the abrogation of regulated Sema-3A expression is responsible for VEGF-driven growth of tumor cells.

Diffuse malignant pleural mesothelioma: Part I. An overview of diagnosis, staging, and treatment options

Diffuse malignant mesothelioma is an uncommon, aggressive malignancy that occurs most often in the pleura of the lung. This article reviews the risk factors, incidence, signs, symptoms, diagnosis, staging, treatment options, and follow-up care of diffuse malignant pleural mesothelioma (DMPM). Curative approaches for treating DMPM are limited, and survival rates rarely exceed two years. Treatments such as surgery, chemotherapy, and radiotherapy have shown limited benefit in improving survival. Extrapleural pneumonectomy combined with multimodal treatments provides a potentially curative approach, and newer efforts in multimodality therapy are promising. Clinical trials utilizing intrapleural chemo-photodynamic, gene, and immunotherapies currently are under way.

Transfer into a mesothelioma cell line of tumor suppressor gene p16 by cholesterol-based cationic lipids

In this work, the tumor suppressor gene p16 was efficiently transferred into FR cells isolated from a patient with malignant mesothelioma using cationic liposomes prepared from trimethyl aminoethane carbamoyl cholesterol (TMAEC-Chol) and triethyl aminopropane carbamoyl cholesterol (TEAPC-Chol). This transfer was performed after preliminary assays were undertaken to find the optimal transfection conditions. Results showed that an efficient transfer of plasmids containing the reporter gene pCMV-beta galactosidase vectorized by TMAEC-Chol/DOPE and TEAPC-Chol/DOPE liposomes into mesothelioma FR cells was obtained as assessed by luminometric measurements of beta-galactosidase activity. Cytotoxicity studied by MTT test showed that at concentrations used for this study, the cationic liposomes have no effect on cell growth. Transfer into mesothelioma FR cells of a plasmid construct containing the tumor suppressor gene p16 was carried out with these liposomes. Western blotting and immunofluorescence showed the presence of p16 in treated cells. An inhibition of cell growth was observed, indicating that efficient tumor suppressor gene transfer can be performed by using cationic liposomes.

Cytoreductive surgery combined with intraoperative hyperthermic intrathoracic chemotherapy for stage I malignant pleural mesothelioma

BACKGROUND

Malignant pleural mesothelioma (MPM) is a disease mostly confined to the thoracic cavity. Untreated, the median survival is <1 year. Cytoreductive surgery combined with intraoperative hyperthermic intrathoracic chemotherapy is used to kill residual tumor cells on the surface of the thoracic cavity while having limited systemic side effects.

METHODS

From August 1998 to August 2001, 22 patients with stage I MPM were included in this study. Two patients were irresectable at operation because of extrathoracic tumor growth. Twenty procedures were performed. After cytoreduction, a perfusion was performed with cisplatin and doxorubicin at 40 degrees C to 41 degrees C for 90 minutes. Adjuvant radiotherapy was given to surgical scars and drainage tracts.

RESULTS

There was no perioperative mortality, but significant morbidity was seen in 13 patients (65%), including bronchopleural fistula, diaphragm rupture, wound dehiscence, persistent air leakage, and chylous effusion. No hair loss or leucopenia was noticed. The median follow-up was 14 months. The median survival (Kaplan-Meier) was 11 months, with a 1-year survival of 42%. A favorable pharmacokinetic ratio was observed for both cisplatin and doxorubicin.

CONCLUSIONS

Cytoreductive surgery combined with hyperthermic intrathoracic chemotherapy for stage I MPM is feasible. However, this treatment is accompanied by considerable morbidity. Survival data were less encouraging.

Surgical treatment of malignant pleural mesothelioma: a review

Despite many years of clinical research, there is still no effective therapy for malignant pleural mesothelioma (MPM). Untreated, the prognosis is poor, with a median survival of < 1 year. Single-agent or combination chemotherapy as well as radiotherapy have not shown persistent improvements in response or survival. In general, MPM is a disease confined to the pleural cavity for a long time before metastasizing. Therefore, focus on local treatment seems rational. Surgical resection has been considered the mainstay of treatment by some. However, surgery alone results in high recurrence rates, and the survival benefit remains questionable. In recent years, the emphasis has been on surgery combined with adjuvant therapies. In this article, the present state of surgical management of MPM will be reviewed.

The role of imaging in the management of primary pleural malignancies

Malignant pleural mesothelioma is a rare tumour, but its incidence is increasing. Imaging is invariably involved in its diagnosis, staging, and follow-up. Although there are some characteristic radiological signs, none are pathognomonic. Computed tomography (CT) and magnetic resonance (MR) have similar local staging accuracies, but have distinct limitations; MR has marginal superiority in specific areas and should probably be offered to surgical candidates. The capabilities of multidector CT await evaluation. The role of positron emission tomography (PET), and PET-CT is undefined, but will likely have a major contribution. The challenges in imaging are matched by controversies in staging and treatment, which require future close multidisciplinary and multicentre collaboration.

Phase II trial of ZD0473 as second-line therapy in mesothelioma

A phase II, open-label, non-comparative, multicentre trial of the platinum analogue ZD0473 as second-line therapy for pleural mesothelioma has been completed. The objectives were to evaluate the activity and tolerability of ZD0473 in patients with relapsed or progressive disease who had received one prior chemotherapy regimen. Forty-seven patients were recruited onto the trial, all aged > 18 years with a life-expectancy > 12 weeks, and World Health Organization (WHO) performance status < or = 2. A starting dose of 120 mg/m2 was administered to 14 patients, six of whom subsequently had their dose escalated to 150 mg/m2. Thirty-three patients received a starting dose of 150 mg/m2. In total, 147 treatment cycles were administered (median number of cycles 3 [range 1-6]). The main toxicity of ZD0473 was haematological (thrombocytopenia) and the most common non-haematological adverse event was nausea. There was no clinically significant nephro-, neuro-, or oto-toxicity. Of the 43 patients evaluable for response, 12% had a minor response (defined by a reduction in lesion size > or = 10% but < 50%), 44% had stable disease, 40% had disease progression, and two patients died before an objective response could be assigned. Median time to progression and death in evaluable patients was 77 days (95% confidence interval [CI]: 44, 105 days) and 203 days (95% CI: 165, 277 days), respectively. In conclusion, although ZD0473 demonstrated a manageable tolerability profile, no complete or partial responses were seen in second-line treatment of mesothelioma. This trial also demonstrates that clinical trials in second-line mesothelioma patients are feasible.

Synergistic effect of the anti-HER-2/neu antibody and cisplatin in immortalized and primary mesothelioma cell lines

Malignant mesothelioma (MM) still remains a therapeutic and diagnostic problem to which new therapeutic perspectives are being continuously tried and tested. Three different primary cultures (MMGe-1, MES MM 98, and MES 1) and one immortalized cell line (MSTO 211 H) of human MM were studied in order to evaluate the HER-2/neu expression. Three out of four cell lines showed a different level of c-erbB-2 expression, the highest being detected on the MSTO 211 H cell line (fibroblastic phenotype), whereas MMGe-1 resulted negative. The effect of the anti-HER-2/neu antibody (Trastuzumab) alone, and in combination with cisplatin (CDDP) at different doses (ranging from 0.1 to 100 microg/ml), was studied on all the c-erB-2 positive cell lines. Trastuzumab was able to inhibit cell proliferation in a time-dependent manner, with growth inhibition also obtained at low concentrations (0.1-1 microg/ml). Combined treatment with Trastuzumab (10 microg/ml) and CDDP (1 microg/ml) showed synergism. Our results were encouraging, and suggest a rationale for further investigations in a clinical setting.

Cancer testis antigens expression in mesothelioma: role of DNA methylation and bioimmunotherapeutic implications

Recent evidences suggest that malignant mesothelioma may be sensitive to immunotherapy; however, little is known about malignant mesothelioma-associated tumour antigens. Focusing on cancer/testis antigens, the expression of well-characterised immunogenic tumour-associated antigens was investigated in malignant mesothelioma cells. At variance with MAGE-4 and NY-ESO-1, malignant mesothelioma cells frequently expressed MAGE-1, -2 and -3, GAGE 1-2, GAGE 1-6, SSX-2 and SSX 1-5, and distinct malignant mesothelioma cells concomitantly expressed at least four cancer/testis antigens. Additionally, the tumour-associated antigens RAGE-1 was expressed at high levels in both benign and malignant mesothelial cells. Lastly, treatment with the DNA hypomethylating agent 5-aza-2'-deoxycytidine induced and up-regulated the expression of the cancer/testis antigen examined in malignant mesothelioma cells. Overall, these findings strongly suggest that cancer/testis antigens-based immunotherapy may represent a suitable therapeutic approach to malignant mesothelioma, and foresee the clinical use of 5-aza-2'-deoxycytidine to design new chemo-immunotherapeutic strategies in malignant mesothelioma patients.

Cytoreductive surgery and intraoperative hyperthermic intrathoracic chemotherapy in patients with malignant pleural mesothelioma or pleural metastases of thymoma

STUDY OBJECTIVES

No established curative treatment is available for pleural thymoma metastases and malignant pleural mesothelioma (MPM). Recently, peritoneal malignancies have been treated by cytoreductive surgery and intraoperative hyperthermic intracavitary perfusion chemotherapy (HIPEC). We investigated the feasibility and safety of this multimodality treatment in the thoracic cavity.

DESIGN

Patients with pleural thymoma metastases or early-stage MPM were enrolled in a feasibility study. Morbidity, recurrence, and survival rates were recorded.

SETTING

The Netherlands Cancer Institute.

PATIENTS

Three patients with pleural thymoma metastases and 11 patients with pleural mesothelioma were treated.

INTERVENTIONS

Cytoreductive surgery and intraoperative hyperthermic intrathoracic perfusion chemotherapy (HITHOC) with cisplatin and adriamycin were performed. The mesothelioma patients received adjuvant radiotherapy on the thoracotomy wound and drainage tracts.

MEASUREMENTS AND RESULTS

Morbidity and mortality rates were 47% and 0%, respectively. Reoperation was necessary in four cases. Severe chemotherapy-related complications were not observed. A solitary mediastinal and a contralateral pleural thymoma recurrence were successfully treated by radiotherapy and a contralateral HITHOC procedure. All thymoma patients were alive and free of disease after a mean follow-up period of 18 months. After a mean follow-up period of 7.4 months, nine mesothelioma patients are alive. Two mesothelioma patients died of contralateral pleural and peritoneal recurrent disease, while one patient is alive with locoregional recurrence.

CONCLUSIONS

Cytoreductive surgery and HITHOC with cisplatin and adriamycin is feasible in patients with pleural thymoma metastases and early-stage MPM, and is associated with acceptable morbidity rates. Early data on locoregional disease control are encouraging, and a phase II study will be conducted.