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Background and Objectives: Due to difficulties in identifying sufficient-sized cohorts there remains uncertainty about prognostic and clinical differences that may be unique to asbestos-related lung cancer (ARLC). In this study, we use the Helsinki Criteria to define a group of ex-workers with lung cancer attributable to asbestos exposure and investigate differences that may exist., Methods: A total of 529 patients seeking workers' compensation for their lung cancer were assigned to either ARLC or the non-ARLC based on parameters defined in the Helsinki Criteria. Clinical and survival details were collected and analyzed., Results: In our study population, ARLC patients were on average older (72.1 ± 7.8) than non-ARLC patients (66.5 ± 10.2, P < 0.001) and were more likely to be diagnosed as a result of incidental findings or screening program (P < 0.001). The groups were similar in terms of clinical characteristics with the only difference being that plaques were more prevalent among ARLC patients (P < 0.001). Differences were observed for median overall survival (OS), ARLC (9 months) and non-ARLC (13 months, P = 0.005), as well for treatment (P = 0.01). After adjusting for age, however, these differences disappeared., Conclusions: Age at diagnosis, pleural plaques, and asymptomatic presentation were the attributes that we identified as significantly different between asbestos-related cancer and other lung cancers. In this cohort, ARLC patients were older diagnosis and with worse overall survival., (© 2022 John Wiley & Sons Australia, Ltd.)

Objective: Malignant pleural mesothelioma (MPM) is a cancer that primarily affects older adults. However this patient population is frequently under-represented in clinical studies. Therefore, we studied the impact of advancing age on treatment utilisation and clinical outcomes in an extensive series of minimally selected MPM patients., Materials and Methods: Patients with MPM receiving compensation from the New South Wales (NSW) Dust Diseases Authority (2002-2009) were assessed. They were categorised by age (<70 years, 70-80 years or > 80 years) and chi-square testing was used to assess the relationship between clinical and demographic variables, age, treatment and overall survival (OS)., Results: We identified 910 patients; 41% were aged <70 years, 40% were aged 70-80 years, and 19% were aged >80 years old. Median OS decreased with increasing age: 13.5 months in <70 years, 9.5 months in 70-80 years and 7.1 months in >80 years as did chemotherapy use (66%, 35% and 8% respectively). Radical surgical intervention, adjuvant, and palliative radiotherapy were less frequently used with advanced age. A Kaplan Meier analysis revealed that there was a significant survival advantage (p < .001) for patients <70 and 70-80 years receiving chemotherapy (16.8 vs 7.0 months; 13.9 vs 5.8 months respectively), but not for patients >80 years., Conclusion: Advancing age group of NSW patients with MPM was associated with reduced treatment utilisation and a decline in OS. Prospective studies are warranted to verify if current treatment guidelines are relevant for the older adults with MPM., (Copyright © 2019. Published by Elsevier Ltd.)

Malignant pleural mesothelioma (MPM), an aggressive malignancy affecting pleural surfaces, occurs in three main histological subtypes. The epithelioid and sarcomatoid subtypes are characterized by cuboid and fibroblastoid cells, respectively. The biphasic subtype contains a mixture of both. The sarcomatoid subtype expresses markers of epithelial-mesenchymal transition (EMT) and confers the worst prognosis, but the signals and pathways controlling EMT in MPM are not well understood. We demonstrate that treatment with FGF2 or EGF induced a fibroblastoid morphology in several cell lines from biphasic MPM, accompanied by scattering, decreased cell adhesion and increased invasiveness. This depended on the MAP-kinase pathway but was independent of TGFβ or PI3-kinase signaling. In addition to changes in known EMT markers, microarray analysis demonstrated differential expression of MMP1, ESM1, ETV4, PDL1 and BDKR2B in response to both growth factors and in epithelioid versus sarcomatoid MPM. Inhibition of MMP1 prevented FGF2-induced scattering and invasiveness. Moreover, in MPM cells with sarcomatoid morphology, inhibition of FGF/MAP-kinase signaling induced a more epithelioid morphology and gene expression pattern. Our findings suggest a critical role of the MAP-kinase axis in the morphological and behavioral plasticity of mesothelioma.

Introduction: Malignant pleural mesothelioma (MPM) is an aggressive malignancy linked to asbestos exposure. On a genomic level, MPM is characterized by frequent chromosomal deletions of tumor suppressors, including microRNAs. MiR-137 plays a tumor suppressor role in other cancers, so the aim of this study was to characterize it and its target Y-box binding protein 1 (YBX1) in MPM., Methods: Expression, methylation, and copy number status of miR-137 and its host gene MIR137HG were assessed by polymerase chain reaction. Luciferase reporter assays confirmed a direct interaction between miR-137 and Y-box binding protein 1 gene (YBX1). Cells were transfected with a miR-137 inhibitor, miR-137 mimic, and/or YBX1 small interfering RNA, and growth, colony formation, migration and invasion assays were conducted., Results: MiR-137 expression varied among MPM cell lines and tissue specimens, which was associated with copy number variation and promoter hypermethylation. High miR-137 expression was linked to poor patient survival. The miR-137 inhibitor did not affect target levels or growth, but interestingly, it increased miR-137 levels by means of mimic transfection suppressed growth, migration, and invasion, which was linked to direct YBX1 downregulation. YBX1 was overexpressed in MPM cell lines and inversely correlated with miR-137. RNA interference-mediated YBX1 knockdown significantly reduced cell growth, migration, and invasion., Conclusions: MiR-137 can exhibit a tumor-suppressive function in MPM by targeting YBX1. YBX1 knockdown significantly reduces tumor growth, migration, and invasion of MPM cells. Therefore, YBX1 represents a potential target for novel MPM treatment strategies., (Copyright © 2017 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)

Malignant pleural mesothelioma (MPM) is an aggressive malignancy with very limited therapeutic options. Fibroblast growth factor (FGF) signals play important roles in mesothelioma cell growth. Several FGFs and FGF receptors (FGFRs) are predicted targets of the miR-15/16 family, which is downregulated in MPM. The aim of this study was to explore the link between the miR-15/16 family and the FGF axis in MPM. Expression analyses via RT-qPCR showed downregulation of the FGF axis after transfection with miR-15/16 mimics. Direct interaction was confirmed by luciferase reporter assays. Restoration of miR-15/16 led to dose-dependent growth inhibition in MPM cell lines, which significantly correlated with their sensitivity to FGFR inhibition. Treatment with recombinant FGF2 prevented growth inhibition and further reduced the levels of FGF/R-targeting microRNAs, indicating a vicious cycle between miR-15/16 down- and FGF/FGFR signaling upregulation. Combined inhibition of two independent miR-15/16 targets, the FGF axis and Bcl-2, resulted in additive or synergistic activity. Our data indicate that post-transcriptional repression of FGF-mediated signals contributes to the tumor suppressor function of the microRNA-15/16 family. Inhibiting hyperactivated FGF signals and Bcl-2 might serve as a novel therapeutic combination strategy in MPM., (© 2017 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.)

Objective: MicroRNAs are frequently downregulated in cancer, and restoring expression has tumour suppressive activity in tumour cells. Our recent phase I clinical trial investigated microRNA-based therapy in patients with malignant pleural mesothelioma. Treatment with TargomiRs, microRNA mimics with novel sequence packaged in EGFR antibody-targeted bacterial minicells, revealed clear signs of clinical activity. In order to detect delivery of microRNA mimics to tumour cells in future clinical trials, we tested hydrolysis probe-based assays specific for the sequence of the novel mimics in transfected mesothelioma cell lines using RT-qPCR., Results: The custom assays efficiently and specifically amplified the consensus mimics. However, we found that these assays gave a signal when total RNA from untransfected and control mimic-transfected cells were used as templates. Further investigation revealed that the reverse transcription step using stem-loop primers appeared to introduce substantial non-specific amplification with either total RNA or synthetic RNA templates. This suggests that reverse transcription using stem-loop primers suffers from an intrinsic lack of specificity for the detection of highly similar microRNAs in the same family, especially when analysing total RNA. These results suggest that RT-qPCR is unlikely to be an effective means to detect delivery of microRNA mimic-based drugs to tumour cells in patients.

Background: TargomiRs are minicells (EnGeneIC Dream Vectors) loaded with miR-16-based mimic microRNA (miRNA) and targeted to EGFR that are designed to counteract the loss of the miR-15 and miR-16 family miRNAs, which is associated with unsuppressed tumour growth in preclinical models of malignant pleural mesothelioma. We aimed to assess the safety, optimal dosing, and activity of TargomiRs in patients with malignant pleural mesothelioma., Methods: In this first-in-man, open-label, dose-escalation phase 1 trial at three major cancer centres in Sydney (NSW, Australia), we recruited adults (aged ≥18 years) with a confirmed diagnosis of malignant pleural mesothelioma, measurable disease, radiological signs of progression after previous chemotherapy, Eastern Cooperative Oncology Group performance status of 0 or 1, life expectancy of 3 months or more, immunohistochemical evidence of tumour EGFR expression, and adequate bone marrow, liver, and renal function. Patients were given TargomiRs via 20 min intravenous infusion either once or twice a week (3 days apart) in a traditional 3 + 3 dose-escalation design in five dose cohorts. The dose-escalation steps planned were 5 × 10 9 , 7 × 10 9 , and 9 × 10 9 TargomiRs either once or twice weekly, but after analysis of data from the first eight patients, all subsequent patients started protocol treatment at 1 × 10 9 TargomiRs. The primary endpoints were to establish the maximum tolerated dose of TargomiRs as measured by dose-limiting toxicity, define the optimal frequency of administration, and objective response (defined as the percentage of assessable patients with a complete or partial response), duration of response (defined as time from the first evidence of response to disease progression in patients who achieved a response), time to response (ie, time from start of treatment to the first evidence of response) and overall survival (defined as time from treatment allocation to death from any cause). Analyses were based on the full analysis set principle, including every patient who received at least one dose of TargomiRs. The study was closed for patient entry on Jan 3, 2017, and registered with ClinicalTrials.gov, number NCT02369198, and the Australian Registry of Clinical Trials, number ACTRN12614001248651., Findings: Between Sept 29, 2014, and Nov 24, 2016, we enrolled 27 patients, 26 of whom received at least one TargomiR dose (one patient died before beginning treatment). Overall, five dose-limiting toxicities were noted: infusion-related inflammatory symptoms and coronary ischaemia, respectively, in two patients given 5 × 10 9 TargomiRs twice weekly; anaphylaxis and cardiomyopathy, respectively, in two patients given 5 × 10 9 TargomiRs once weekly but who received reduced dexamethasone prophylaxis; and non-cardiac pain in one patient who received 5 × 10 9 TargomiRs once weekly. We established that 5 × 10 9 TargomiRs once weekly was the maximum tolerated dose. TargomiR infusions were accompanied by transient lymphopenia (25 [96%] of 26 patients), temporal hypophosphataemia (17 [65%] of 26 patients), increased aspartate aminotransferase or alanine aminotranferase (six [23%] of 26 patients), and increased alkaline phosphatase blood concentrations (two [8%]). Cardiac events occurred in five patients: three patients had electrocardiographic changes, one patient had ischaemia, and one patient had Takotsubo cardiomyopathy. Of the 22 patients who were assessed for response by CT, one (5%) had a partial response, 15 (68%) had stable disease, and six (27%) had progressive disease. The proportion of patients who achieved an objective response was therefore one (5%) of 22, and the duration of the objective response in that patient was 32 weeks. Median overall survival was 200 days (95% CI 94-358). During the trial, 21 deaths occurred, of which 20 were related to tumour progression and one was due to bowel perforation., Interpretation: The acceptable safety profile and early signs of activity of TargomiRs in patients with malignant pleural mesothelioma support additional studies of TargomiRs in combination with chemotherapy or immune checkpoint inhibitors., Funding: Asbestos Diseases Research Foundation., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Introduction: The upregulation of programmed death ligand 1 (PD-L1) is found in many cancers and contributes to evasion of the host's immune defense. In malignant pleural mesothelioma (MPM), PD-L1 expression is associated with the nonepithelioid histological subtype and poor prognosis, but the pathways involved in control of PD-L1 expression in MPM are poorly understood. To address one possible means of PD-L1 regulation we investigated the relationship between dysregulated microRNA levels and PD-L1 expression., Methods: PD-L1 expression was analyzed by immunohistochemistry in tissue microarrays prepared from samples from patients undergoing an operation (pleurectomy with or without decortication). MicroRNA expression was analyzed by reverse-transcriptase quantitative polymerase chain reaction. Regulation of PD-L1 expression in cell lines was assessed after transfection with microRNA mimics and small interfering RNAs. Interaction between microRNAs and PD-L1 was analyzed by using argonaute-2 immunoprecipitation and a luciferase reporter assay., Results: In a series of 72 patients with MPM, 18 (25%) had positive PD-L1 staining, and this was more common in patients with the nonepithelioid subtype (p = 0.01). PD-L1 expression was associated with poor survival (median overall survival 4.0 versus 9.2 months with positive versus negative PD-L1 expression [p < 0.001]), and in multivariate analyses, PD-L1 expression remained a significant adverse prognostic indicator (hazard ratio = 2.2, 95% confidence interval: 1.2-4.1, p < 0.01). In the same patient series, PD-L1 expression was also associated with downregulation of microRNAs previously shown to have tumor suppressor activity in MPM. The median microRNA expression levels of miR-15b, miR-16, miR-193a-3p, miR-195, and miR-200c were significantly lower in the PD-L1-positive samples. Transfecting MPM cell lines with mimics corresponding to miR-15a and miR-16, both of which are predicted to target PD-L1, led to downregulation of PD-L1 mRNA and protein. In addition, miR-193a-3p, with an alternative G-U-containing target site, also caused PD-L1 downregulation., Conclusions: Together, these data suggest that tumor suppressor microRNAs contribute to the regulation of PD-L1 expression in MPM., (Copyright © 2017 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.)

Background and Objective: Whilst the impact of clinicopathological factors on the prognosis of malignant pleural mesothelioma (MPM) is well understood, socioeconomic and geographic factors have received less attention. We analysed the relationship between geographic and socioeconomic factors upon survival and treatment provision in a large series of patients with MPM., Methods: We assessed MPM patients awarded compensation between 2002 and 2009 with additional MPM incidence data from the New South Wales (NSW) Cancer Registry. The impact of geographic remoteness, distance from oncological multidisciplinary team (MDT) and Index of Relative Socioeconomic Advantage and Disadvantage (IRSAD) upon survival, clinical features and treatment received was analysed., Results: We identified 910 patients (67% residing in major cities; 92% <50 km from MDT). Median overall survival was 10.0 months. On multivariate analysis, age >70 (hazard ratio (HR) = 1.39), male gender (HR =1.36), non-epithelioid histological subtype (HR = 2.18) and IRSAD status by decreasing quintile (HR = 1.06) were independent prognostic factors. There was no significant advantage for patients residing in major cities (10.6 months vs 8.8 months; P = 0.162) or within 50 km of MDT (10.3 months vs 7.8 months; P = 0.539). Patient's geographic location and distance to MDT did not impact chemotherapy, adjuvant radiotherapy or extrapleural pneumonectomy provision. Socioeconomically disadvantaged patients were significantly less likely to receive chemotherapy (37.4% vs 54.8%; P = 0.001)., Conclusion: This study provides evidence for differences in the treatment and survival according to socioeconomic status for compensated MPM patients in NSW. Further research is warranted to seek additional explanations for the differences noted by comparing the treatments and outcomes of compensated and non-compensated MPM patients in NSW., (© 2017 Asian Pacific Society of Respirology.)

miRNAs are responsible for post-transcriptional control of gene expression, and are frequently downregulated in cancer. It has become well established that restoring miRNA levels can inhibit tumor growth, and many studies have demonstrated this in preclinical models. This in turn has led to the first clinical trials of miRNA replacement therapy. This special report focuses on the development of TargomiRs - miRNA mimics delivered by targeted bacterial minicells - and the very first clinical experience of a miRNA replacement therapy in thoracic cancer patients in the Phase I MesomiR-1 trial.

Introduction: The deregulation of activin expression is often observed in various malignancies. Previous studies indicate that activin A plays a protumourigenic role in malignant pleural mesothelioma (MPM). The aim of the study was to evaluate circulating activin A level as a biomarker in MPM., Methods: Plasma samples were collected from 129 MPM patients in four institutions at the time of diagnosis or before surgical resection. Samples from 45 healthy individuals and from 16 patients with non-malignant pleural diseases served as controls. Circulating activin A was measured by enzyme-linked immunosorbent assay and correlated to clinicopathological variables., Results: Plasma activin A level was significantly elevated in MPM patients (862 ± 83 pg/ml) when compared to healthy controls (391 ± 21 pg/ml; P < 0.0001). Patients with pleuritis or fibrosis only showed a modest increase (versus controls; 625 ± 95 pg/ml; P = 0.0067). Sarcomatoid (n = 10, 1629 ± 202 pg/ml, P = 0.0019) and biphasic (n = 23, 1164 ± 233 pg/ml, P = 0.0188) morphology were associated with high activin A levels when compared to epithelioid histology (n = 94, 712 ± 75 pg/ml). The tumour volume showed a positive correlation with increased circulating activin A levels. MPM patients with below median activin A levels had a significantly longer overall survival when compared to those with high activin A levels (median survival 735 versus 365 d, P < 0.0001). Importantly, circulating activin A levels were exclusively prognostic in epithelioid MPM., Conclusions: Our findings suggest that the measurement of circulating activin A may support the histological classification of MPM and at the same time help to identify epithelioid MPM patients with poor prognosis., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Introduction: Malignant pleural mesothelioma (MPM) and malignant peritoneal mesothelioma (MPeM) are often grouped together in descriptive epidemiological analyses, resulting in limited understanding of epidemiological patterns for these tumour types., Methods: We studied patterns in the incidence, mortality and survival of people diagnosed with MPM (n=4,076) and MPeM (n=293) in New South Wales (NSW), Australia, 1972-2009. We also calculated 5-year relative survival for people diagnosed 1972-2006 followed up to 2007. We assessed patterns for each tumour type and histological subtype and, where possible, by combination of these categories., Results: Annual MPM cases steadily increased over time (n=208 in 2009). There was an increasing trend in the MPM age-standardised incidence rate from 1972 up to 1994. This rate increase has levelled off in the past 10 years. Since 1999, 11 cases of MPeM were diagnosed each year, on average. Five-year relative survival remained stable for MPM and MPeM. However, 5-year relative survival in 2002-2006 was substantially higher for people with MPM epithelioid histological subtype (11.7% [95%CI 6.8-18.2%]) compared to all other non-epithelioid histological subtypes (6.9% [95%CI 5.0-9.1%]), a 70% difference. Survival was also greater for women with MPM (13.4% [95%CI 8.5-19.4%]) compared to men (7.0% [95%CI 5.1-9.2%])., Interpretation: MPM incidence rates have stabilised since the mid-1990s, suggesting that maximum incidence levels have been reached. When more up-to-date data are available, survival estimates should be reanalysed to include people likely to benefit from the wide introduction of combination chemotherapy in 2007, including pemetrexed., (© 2015 Public Health Association of Australia.)

Background: Malignant pleural mesothelioma (MPM) is an aggressive, locally invasive, cancer elicited by asbestos exposure and almost invariably a fatal diagnosis. To date, we are one of the leading laboratory that compared microRNA expression profiles in MPM and normal mesothelium samples in order to identify dysregulated microRNAs with functional roles in mesothelioma. We interrogated a significant collection of MPM tumors and normal pleural samples in our biobank in search for novel therapeutic targets., Methods: Utilizing mRNA-microRNA correlations based on differential gene expression using Gene Set Enrichment Analysis (GSEA), we systematically combined publicly available gene expression datasets with our own MPM data in order to identify candidate targets for MPM therapy., Results: We identified enrichment of target binding sites for the miR-17 and miR-30 families in both MPM tumors and cell lines. RT-qPCR revealed that members of both families were significantly downregulated in MPM tumors and cell lines. Interestingly, lower expression of miR-17-5p (P = 0.022) and miR-20a-5p (P = 0.026) was clearly associated with epithelioid histology. We interrogated the predicted targets of these differentially expressed microRNA families in MPM cell lines, and identified KCa1.1, a calcium-activated potassium channel subunit alpha 1 encoded by the KCNMA1 gene, as a target of miR-17-5p. KCa1.1 was overexpressed in MPM cells compared to the (normal) mesothelial line MeT-5A, and was also upregulated in patient tumor samples compared to normal mesothelium. Transfection of MPM cells with a miR-17-5p mimic or KCNMA1-specific siRNAs reduced mRNA expression of KCa1.1 and inhibited MPM cell migration. Similarly, treatment with paxilline, a small molecule inhibitor of KCa1.1, resulted in suppression of MPM cell migration., Conclusion: These functional data implicating KCa1.1 in MPM cell migration support our integrative approach using MPM gene expression datasets to identify novel and potentially druggable targets.

Introduction: Global asbestos consumption has shifted toward lower income countries, particularly in the Asian region including Vietnam where asbestos and asbestos-containing products have been imported since the late 1960s., Methods: This pilot descriptive epidemiological study aimed to provide contemporary estimates of malignant mesothelioma incidence (histological subtype M9050/3; ICD-O-3) by gender and age group as recorded across nine cancer registries in Vietnam., Results: We identified 148 incident cases of malignant mesothelioma during 1987-2013. The majority of cases were recorded in the Hanoi region (n = 93) and were aged 55 years or older (n = 96)., Discussion: By carefully reviewing existing cancer registry records in Vietnam, we identified a larger number of malignant mesothelioma cases than previously estimated. We recommend the use of cancer registry data in tracking future asbestos-related disease in Vietnam.

Background: We aimed to identify prognostic blood biomarkers using proteomics-based approaches in malignant pleural mesothelioma (MPM)., Methods: Plasma samples from 12 MPM patients were used for exploratory mass spectrometry and ELISA analyses. The significance of secreted protein acidic and rich in cysteine (SPARC) was examined in sera from a Dutch series (n=97). To determine the source of the circulating SPARC, we investigated SPARC expression in MPM tumours and healthy controls, as well as the expression and secretion from cell lines and xenografts., Results: Secreted protein acidic and rich in cysteine was identified as a putative prognostic marker in plasma. Validation in the Dutch series showed that the median survival was higher in patients with low SPARC compared with those with high SPARC (19.0 vs 8.8 months; P=0.01). In multivariate analyses, serum SPARC remained as an independent predictor (HR 1.55; P=0.05). In MPM tumour samples, SPARC was present in the tumour cells and stromal fibroblasts. Cellular SPARC expression was higher in 5 out of 7 cell lines compared with two immortalized mesothelial lines. Neither cell lines nor xenograft tumours secreted detectable SPARC., Conclusions: Low circulating SPARC was associated with favourable prognosis. Secreted protein acidic and rich in cysteine was present in both tumour cells and stromal fibroblasts; and our in vitro and in vivo experiments suggest that stromal fibroblasts are a potential source of circulating SPARC.

Background: Australia is known to have had one of the highest per-capita asbestos consumption rates, yet there are few contemporary reports on malignant mesothelioma trends., Methods: Data on 10 930 people with malignant pleural mesothelioma (MPM) and 640 people with malignant peritoneal mesothelioma diagnosed in Australia during 1982-2009 were analysed. Observed incidence rate trends were quantified. Incidence rates were projected up to 2030 using observed incident cases during 1982-2012. The relative per-decade change in excess mortality during 1999-2009 was estimated., Results: During 1982-2009, acceleration in MPM age-standardised incidence rates were highest for women and those aged 75 years and above, with average annual percentage changes of +4.9 (95% CI 3.6 to 6.2) and +7.2 (95% CI 5.4 to 9.0), respectively. Age-standardised incidence rates for men with MPM aged 0-64 years decelerated rapidly during 2003-2009, an average annual percentage change of -5.1% (95% CI -7.6% to -2.5%). Overall, male age-specific MPM incidence rates in the age group of 65-74 year during 2010-2030 are projected to decline with rates projected to increase for older men and women with MPM. There was a statistically significant 16% relative reduction in the excess mortality rate (EMR) up to 5 years postdiagnosis for people diagnosed with malignant pleural and peritoneal mesothelioma combined in 2009 compared with those diagnosed in 1999, an EMR ratio of 0.84 (95% CI 0.77 to 0.92)., Conclusions: Australia's malignant mesothelioma incidence rates appear to have reached maximum levels but with differences over time by age, gender and tumour location. Improvements over time in survival provide a glimpse of hope for this almost invariably fatal disease., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Australia is known to have had the highest per-capita asbestos consumption level of any nation, reaching a peak in the 1970s. Although crocidolite was effectively banned in the late 1960s, and amosite use ceased in the mid 1980s, a complete asbestos ban was not implemented until 2003. This resulted in an epidemic of asbestos-related disease, which has only now reached its peak. Between 1982 and 2011, 13,036 individuals were newly diagnosed with malignant mesothelioma, with 690 diagnosed in 2011. A further 778 cases were identified between 1945 and 1981 from retrospective searches and the first 2 years of the Australian Mesothelioma Program. The age-standardized malignant mesothelioma incidence rate has leveled off in the last 10 years (2.8 per 100,000 in 2011). There has been a marked increase over time in the age-specific incidence rates for individuals aged 75 years or older. Data from the current Australian Mesothelioma Registry on asbestos exposure history in Australia is available for 449 subjects diagnosed between July 1, 2010, and April 1, 2015. This asbestos exposure history data show that 60% (n = 268) of cases had probable or possible occupational asbestos exposure, with trade-based jobs being the most frequent sources of occupational asbestos exposure. In addition, out of the 449 cases, 377 were recorded as having probable or possible nonoccupational asbestos exposure. Continuous vigilance toward changes over time in the settings in which people are exposed to asbestos and in the descriptive epidemiology of malignant mesothelioma is recommended to enable a comprehensive understanding of the current and future impact of asbestos-related diseases in Australia.

Background: Fibulin-3 (FBLN3) was recently presented as a promising novel biomarker for malignant pleural mesothelioma (MPM), warranting independent validation studies., Methods: ELISA was used to measure cellular and secreted FBLN3 in cell lines, in plasma of xenograft tumour-bearing mice, in plasma from two independent series of MPM and non-MPM patients and in pleural fluid from a third series. Diagnostic and prognostic potential of FBLN3 was assessed by receiver operating characteristics curve analysis and Kaplan-Meier method, respectively., Results: FBLN3 was expressed in all MPM and benign mesothelial cell lines tested, and a correlation was observed between cellular protein expression and secreted levels. Human FBLN3 was detectable in plasma of tumour-bearing mice, suggesting that MPM cells contribute to levels of circulating FBLN3. Plasma FBLN3 was significantly elevated in MPM patients from the Sydney cohort, but not the Vienna cohort, but the diagnostic accuracy was low (63%, (95% CI: 50.1-76.4) and 56% (95% CI: 41.5-71.0), respectively). Although FBLN3 levels in pleural effusions were not significantly different between cases and controls, FBLN3 levels in pleural effusion fluid were found to be independently associated with prognosis (hazard ratio of 9.92 (95% CI: 2.14-45.93))., Conclusions: These data confirm the potential prognostic value of pleural effusion FBLN3, but question the diagnostic value of this protein in MPM patients.

Malignant pleural mesothelioma (MPM) is an asbestos-induced cancer with poor prognosis that displays characteristic alterations in microRNA expression. Recently it was reported that the expression of a subset of microRNAs can distinguish between MPM and adenocarcinoma of the lung. However, the functional importance of these changes has yet to be investigated. We compared expression of miR-192, miR-193a-3p and the miR-200 family in normal pleura and MPM tumor specimens and found a statistically significant reduction in the levels of miR-193a-3p (3.1-fold) and miR-192 (2.8-fold) in MPM. Transfection of MPM cells with a miR-193a-3p mimic resulted in inhibition of growth and an induction of apoptosis and necrosis in vitro. The growth inhibitory effects of miR-193a-3p were associated with a decrease in MCL1 expression and were recapitulated by RNAi-mediated MCL1 silencing. Targeted delivery of miR-193a-3p mimic using EDV minicells inhibited MPM xenograft tumour growth, and was associated with increased apoptosis. In conclusion, miR-193a-3p appears to have importance in the biology of MPM and may represent a target for therapeutic intervention.

Aims: Chemotherapy with cisplatin and pemetrexed has been shown to provide a survival benefit and improvement in quality of life in patients with malignant pleural mesothelioma (MPM). The reported chemotherapy utilization rates range from 18% to 61%. This study aimed to estimate the proportion of MPM patients that should receive chemotherapy based on best available evidence., Methods: An optimal chemotherapy utilization model for MPM was constructed using indications for chemotherapy identified from evidence-based MPM treatment guidelines. Epidemiological data on the proportion of patients and their tumor-related attributes were combined with the chemotherapy indications to estimate the optimal chemotherapy utilization rate using decision analysis software (TreeAge Pro 2007). Sensitivity analyses were performed to assess the impact of major variations in the epidemiological data on the optimal chemotherapy utilization rate. The optimal rate was compared with the actual rate reported in the literature., Results: Chemotherapy is recommended at least once during the disease trajectory in 65% of MPM patients. Sensitivity analyses indicate an optimal utilization rate ranging from 50% to 65%. This optimal rate is relatively comparable to the rates mentioned in contemporary reports from Canada (61% between 2003 and 2005) and Australia (54% between 2007 and 2009) and high when compared with data from the Netherlands (36% during 2005-2006)., Conclusion: An evidence-based model provided an optimal chemotherapy utilization rate of 65% for patients with MPM. Chemotherapy for MPM may be underutilized and barriers are likely multifactorial., (© 2014 Wiley Publishing Asia Pty Ltd.)

Background: Prognosis of malignant pleural mesothelioma (MPM) is poor, and predicting the outcomes of treatment is difficult. Here we investigate the potential of microRNA expression to estimate prognosis of MPM patients., Methods: Candidate microRNAs from microarray profiling of tumor samples from 8 long (median: 53.7 months) and 8 short (median: 6.4 months) survivors following extrapleural pneumonectomy (EPP) were validated by RT-qPCR in 48 additional EPP samples. Kaplan-Meier log ranking was used to further explore the association between microRNA expression and overall survival (OS). Binary logistic regression was used to construct a microRNA signature (miR-Score) that was able to predict an OS of ≥20 months. Performance of the miR-Score was evaluated by receiver operating characteristic (ROC) curve analysis and validated in a series of 43 tumor samples from patients who underwent palliative surgery [pleurectomy/decortication (P/D)]., Results: The miR-Score, using expression data of six microRNAs (miR-21-5p, -23a-3p, -30e-5p, -221-3p, -222-3p, and -31-5p), enabled prediction of long survival with an accuracy of 92.3% for EPP and 71.9% for palliative P/D. Hazard ratios for score-negative patients were 4.12 (95% CI: 2.03-8.37) for EPP and 1.93 (95% CI: 1.01-3.69) for P/D. Importantly, adding the miR-Score to a set of clinical selection criteria (histology, age, gender) increased predictive accuracy in the independent validation set from 76.3% for clinical factors only to 87.3%., Conclusions: This study has identified a novel 6-microRNA signature (miR-Score) that can accurately predict prognosis of MPM patients., (Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

Background: Although the prognosis of most patients presenting with malignant pleural mesothelioma (MPM) is poor, a small proportion survives long term. We investigated factors associated with survival in a large patient series., Methods: All patients registered with the NSW Dust Diseases Board (2002-2009) were included in an analysis of prognostic factors using Kaplan-Meier and Cox regression analysis. On the basis of these analyses, we developed a risk score (Prognostic Index (PI))., Results: We identified 910 patients: 90% male; histology (epithelioid 60%; biphasic 13%; sarcomatoid 17%); stage (Tx-I-II 48%; III-IV 52%); and calretinin expression (91%)., Treatment: chemotherapy(CT) 44%, and extrapleural-pneumonectomy (EPP) 6%. Median overall survival (OS) was 10.0 months. Longer OS was associated with: age <70 (13.5 vs 8.5 months; P<0.001); female gender (12.0 vs 9.9 months; P<0.001); epithelioid subtype (13.3 vs 6.2 months; P<0.001); ECOG status 0 (27.4 vs 9.7 months; P=0.015), calretinin expression (10.9 vs 5.5 months; P<0.001); neutrophil-lymphocyte ratio (NLR) <5 (11.9 vs 7.5 months; P<0.001); platelet count <400 (11.5 vs 7.2 months; P<0.001); and normal haemoglobin (16.4 vs 8.8 months; P<0.001). On time-dependent analysis, patients receiving pemetrexed-based chemotherapy (HR=0.83; P=0.048) or EPP (HR=0.41; P<0.001) had improved survival. Age, gender, histology, calretinin and haematological factors remained significant on multivariate analysis. In all, 24% of patients survived >20 months: 16% of these receiving EPP, and 66% CT. The PI offered improved prognostic discrimination over one of the existing prognostic models (EORTC)., Conclusions: We identified calretinin expression, age, gender, histological subtype, platelet count and haemoglobin level as independent prognostic factors. Patients undergoing EPP or pemetrexed-based chemotherapy demonstrated better survival, but 84% and 34% of long survivors, respectively, did not receive radical surgery or chemotherapy.

Malignant pleural mesothelioma (MPM) is an almost invariably fatal, asbestos-related malignancy arising from the mesothelial membrane lining the thoracic cavities. Despite some improvements in treatment, therapy is not considered curative and median survival following diagnosis is less than 1 year. Although still classed as a rare cancer, the incidence of MPM is increasing, and the limited progress in treating the disease makes the identification of new therapies a priority. As there is evidence for expression of the integrins αvβ3 and αvβ5 in MPM, there is a rationale for investigating the effects on MPM of cilengitide, a synthetic peptide inhibitor of integrin αv heterodimer with high specificity for αvβ3 and αvβ5. In mesothelial cells (MC) and 7 MPM cell lines, growth inhibition by cilengitide was associated with the expression level of its target integrins. Furthermore, cilengitide caused cell detachment and subsequent death of anoikis-sensitive cells. It also suppressed invasion of MPM cells in monolayer and three-dimensional cultures. Gene knockdown experiments indicated that these effects of cilengitide were, at least partly, due to antagonism of αvβ3 and αvβ5.

Background: Malignant pleural mesothelioma (MPM) is an aggressive tumour originating in the thoracic mesothelium. Prognosis remains poor with 9- to 12-month median survival, and new targets for treatments are desperately needed., Methods: Utilising an RNA interference (RNAi)-based screen of 40 genes overexpressed in tumours, including genes involved in the control of cell cycle, DNA replication and repair, we investigated potential therapeutic targets for MPM. Following in vitro characterisation of the effects of target silencing on MPM cells, candidates were assessed in tumour samples from 154 patients., Results: Gene knockdown in MPM cell lines identified growth inhibition following knockdown of NDC80, CDK1 and PLK1. Target knockdown induced cell-cycle arrest and increased apoptosis. Using small-molecule inhibitors specific for these three proteins also led to growth inhibition of MPM cell lines, and Roscovitine (inhibitor of CDK1) sensitised cells to cisplatin. Protein expression was also measured in tumour samples, with markedly variable levels of CDK1 and PLK1 noted. PLK1 expression in over 10% of cells correlated significantly with a poor prognosis., Conclusion: These results suggest that RNAi-based screening has utility in identifying new targets for MPM, and that inhibition of NDC80, CDK1 and PLK1 may hold promise for treatment of this disease.

Background: Malignant pleural mesothelioma (MPM) is recalcitrant to treatment and new approaches to therapy are needed. Reduced expression of miR-15/16 in a range of cancer types has suggested a tumour suppressor function for these microRNAs, and re-expression has been shown to inhibit tumour cell proliferation. The miR-15/16 status in MPM is largely unknown., Materials and Methods: MicroRNA expression was analysed by TaqMan-based RT-qPCR in MPM tumour specimens and cell lines. MicroRNA expression was restored in vitro using microRNA mimics, and effects on proliferation, drug sensitivity and target gene expression were assessed. Xenograft-bearing mice were treated with miR-16 mimic packaged in minicells targeted with epidermal growth factor receptor (EGFR)-specific antibodies., Results: Expression of the miR-15 family was consistently downregulated in MPM tumour specimens and cell lines. A decrease of 4- to 22-fold was found when tumour specimens were compared with normal pleura. When MPM cell lines were compared with the normal mesothelial cell line MeT-5A, the downregulation of miR-15/16 was 2- to 10-fold. Using synthetic mimics to restore miR-15/16 expression led to growth inhibition in MPM cell lines but not in MeT-5A cells. Growth inhibition caused by miR-16 correlated with downregulation of target genes including Bcl-2 and CCND1, and miR-16 re-expression sensitised MPM cells to pemetrexed and gemcitabine. In xenograft-bearing nude mice, intravenous administration of miR-16 mimics packaged in minicells led to consistent and dose-dependent inhibition of MPM tumour growth., Conclusions: The miR-15/16 family is downregulated and has tumour suppressor function in MPM. Restoring miR-16 expression represents a novel therapeutic approach for MPM.

Introduction: Epigenetic inactivation of tumor suppressor genes is involved in the development of malignant pleural mesothelioma (MPM). ZIC1, a potential tumor suppressor gene involved in regulating cell growth and apoptosis, was investigated in MPM cell lines and tumors., Methods: ZIC1 expression and promoter methylation were evaluated in MPM cell lines and tumor samples by quantitative polymerase chain reaction (PCR), Combined Bisulfite Restriction Analysis, and methylation-specific PCR. ZIC1 was reexpressed in cell lines and functional effects were assessed. miRNA expression was quantified by microarray and reverse transcription quantitative PCR. ZIC1 knockdown and miRNA inhibitors were used to study the relationship between ZIC1 and miRNA expression and confirmed by chromatin immunoprecipitation PCR., Results: ZIC1 expression was low in MPM cells, and was correlated with ZIC1 promoter methylation and reversed upon decitabine treatment. ZIC1 reexpression inhibited proliferation and invasion in MPM cells whereas knockdown enhanced the growth of MeT-5A. In MPM tumor samples ZIC1 expression was either low or undetectable, with promoter methylation observed in 16 of 24 cases. The overexpression of miR-23a and miR-27a was reduced by ZIC1 reexpression, with inhibitors of miR-23a or miR-27a reducing colony formation. miR-23a overexpression was also associated with shorter survival of MPM patients., Conclusion: ZIC1 is down-regulated in MPM through promoter methylation and acts as a tumor suppressor through down-regulation of its direct targets miR-23a and miR-27a.

Pleural malignant mesothelioma (MM) includes several unusual and even rare but distinctive histological subtypes, in addition to the usual subdivision into epithelioid, biphasic and sarcomatoid MM. Criteria for discrimination between fibrous pleuritis versus desmoplastic mesothelioma include evidence of neoplastic invasion for diagnosis of desmoplastic MM, but this histological assessment is complicated by the recently-described 'fake fat phenomenon' in cases of fibrous pleuritis. The distinction between biphasic and monophasic synovial sarcoma of the pleura versus biphasic and sarcomatoid MM can be problematical and is most cogently based upon molecular detection of the t(X;18) translocation, whereas a clear diagnosis of MM for a pleural tumour histologically resembling synovial sarcoma is favoured by a negative result for this translocation and, probably, microRNA evidence supportive of a diagnosis of MM. Aquaporin-1 (AQP1) is a molecule involved in the growth of MM cells, and yet is a factor reported to correlate with improved survival rates for MM with an epithelioid component, in comparison to AQP1-poor MM, as assessed from AQP1 expression by epithelioid MM cells only (apart from co-expression by stromal endothelial cells in addition to the tumour cells). Recent reports have also focused upon germline mutations in the BRCA1-associated protein 1 (BAP1), not only in cases of familial mesothelioma, but also BAP1 deletion in sporadic MM. Prognostic factors for MM include not only the histological subtypes, but other independent variables that include (among others), AQP1 expression by mesothelioma cells, the clinical status of the patient, the serum neutrophil:lymphocyte ratio and blood thrombocytosis.

The detection of neoplastic invasion remains the linchpin for a clear diagnosis of malignant mesothelioma. Cytology-only diagnosis of epithelioid mesothelioma on aspirated effusion fluid remains controversial. A major problem is poor sensitivity, although cytodiagnosis is achievable in many cases at a high order of specificity, especially when a large volume of effusion fluid is submitted for cytological evaluation, enabling the preparation of cell-block sections for immunohistochemical investigation and when the cytological findings can be correlated with imaging studies to assess the anatomical distribution of the lesion and evidence of nodularity of the pleural disorder and, in some cases, to demonstrate evidence of invasion. Although 'positive' and 'negative' immunohistochemical markers have proved remarkably effective in distinguishing between epithelioid mesothelioma and secondary carcinoma and other malignant tumours metastatic to serosal membranes, no mesothelial marker has 100% sensitivity and specificity for mesothelioma diagnosis, so that panels of 'positive' antibodies and markers with negative predictive value are required. At present, no tissue or serum marker (including the molecular detection of p16/CDKN2A) has been proved to have sufficient specificity, consistency and reproducibility that it can replace evidence of invasion as the decisive marker for diagnosis when there is any uncertainty concerning a diagnosis of epithelioid mesothelioma and in the case of atypical fibrous lesions of the pleura (especially collagen-rich lesions, namely fibrous pleuritis vs desmoplastic mesothelioma), in which even the assessment of invasion can be problematical as illustrated in part 2 of this review.

Aims: The accurate diagnosis of malignant pleural mesothelioma (MPM) is essential for therapeutic and legal reasons. In 2006 the International Mesothelioma Panel advocated the use of a panel, including two mesothelial and two non-mesothelial immunohistochemical (IHC) markers. We assessed the changing use of IHC for the diagnosis of MPM in Australia over two decades in the context of current best practice., Methods: Patients with a confirmed clinico-pathological diagnosis of MPM who underwent extrapleural pneumonectomy or pleurectomy and/or decortication between 1988 and 2006 were identified from the cardiothoracic database at Royal Prince Alfred Hospital and combined with consecutive patients reviewed by the Dust Diseases Board between March 2007 and March 2009. Initial diagnostic pathology reports were reviewed., Results: A total of 289 patients were identified. A median of six IHC stains per sample was performed (range 0-18): two (range 0-5) mesothelial markers, two (0-6) carcinoma markers and two epithelial markers. A trend to the higher usage of antibodies in epithelioid tumors versus biphasic and sarcomatoid tumors was noted (P = 0.148 and 0.389, respectively). Testing increased from a median of three stains per sample (1988-1997) to seven (2006-2009). Labeling specimens with > 2 mesothelial markers and > 2 carcinoma markers increased to 72 and 67 percent, respectively, after 2006., Conclusion: Reflecting the acceptance of diagnostic panels and increased availability of antibodies, an increase in the use of IHC stains for MPM diagnosis has occurred over the past two decades although uncertainty persists as to the optimal panel composition., (© 2012 Wiley Publishing Asia Pty Ltd.)

Malignant Pleural Mesothelioma (MPM) is an aggressive cancer that is often diagnosed at an advanced stage and is characterized by a long latency period (20-40 years between initial exposure and diagnosis) and prior exposure to asbestos. Currently accurate diagnosis of MPM is difficult due to the lack of sensitive biomarkers and despite minor improvements in treatment, median survival rates do not exceed 12 months. Accumulating evidence suggests that aberrant expression of long non-coding RNAs (lncRNAs) play an important functional role in cancer biology. LncRNAs are a class of recently discovered non-protein coding RNAs >200 nucleotides in length with a role in regulating transcription. Here we used NCode long noncoding microarrays to identify differentially expressed lncRNAs potentially involved in MPM pathogenesis. High priority candidate lncRNAs were selected on the basis of statistical (P<0.05) and biological significance (>3-fold difference). Expression levels of 9 candidate lncRNAs were technically validated using RT-qPCR, and biologically validated in three independent test sets: (1) 57 archived MPM tissues obtained from extrapleural pneumonectomy patients, (2) 15 cryopreserved MPM and 3 benign pleura, and (3) an extended panel of 10 MPM cell lines. RT-qPCR analysis demonstrated consistent up-regulation of these lncRNAs in independent datasets. ROC curve analysis showed that two candidates were able to separate benign pleura and MPM with high sensitivity and specificity, and were associated with nodal metastases and survival following induction chemotherapy. These results suggest that lncRNAs have potential to serve as biomarkers in MPM.

Purpose: Malignant pleural mesothelioma (MPM) is considered a treatment-resistant disease. We determined the proportion of patients who received treatment in the last month of life and potential factors associated with use of chemotherapy at the end of life., Methods: Consenting MPM patients compensated by the Dust Diseases Board (DDB) were included. Patient, treatment and outcome details were obtained through the DDB, treating physicians and Medicare Australia. The association between potential factors (age, gender, geographical location, disease stage, histological subtype, palliative care referral, length of first line chemotherapy and lines of treatment) and chemotherapy use in the last month of life was determined., Results: A total of 147 MPM patients were included in the analysis: 78 received chemotherapy, 50 had radiotherapy and 116 had surgery (77 received more than one treatment modality whilst 56 received one treatment modality). Twenty-one patients received treatment in their last month of life: nine received chemotherapy; six, radiotherapy and six had surgery. Those who were treated with second or subsequent lines of chemotherapy were more at risk of receiving chemotherapy until the end of life (six of 19 patients, i.e., 32 %) compared to those who were only treated with first-line therapy (three of 59 patients, i.e., 5 %; p < 0.01). Patients who received chemotherapy at the end of life had shorter survival compared to those who did not receive chemotherapy at the end of life (5.3 vs. 12.5 months, respectively; p = 0.01)., Conclusions: Chemotherapy utilisation in the last month of life is not uncommon in this series of MPM patients. Patients who failed previous chemotherapy were more likely to receive chemotherapy near the end of life. More careful consideration of when to cease chemotherapy needs to be made as patients who received chemotherapy at the end of life had poorer survival outcome.

Background: The silent epidemic of mesothelioma in Australia is steadily increasing, and 30% of cases occur in New South Wales (NSW)., Aim: To describe the patterns of care and outcomes of patients with malignant pleural mesothelioma (MPM) in NSW., Methods: MPM patients in NSW applying for compensation at the NSW Dust Diseases Board from 2007 to 2009 were included. Survival from time of diagnosis was determined by the Kaplan-Meier method. The Chi-squared test was used to determine if there was an association between utilisation of treatment and geographical location., Results: A total of 138 patients was included: median age was 72.5; 91.3% male; 60.1% epithelial subtype; and 65.2% lived in major cities. All patients had at least one chest X-ray and computed tomography scan, and 21% had a positron emission tomography scan; 93.5% and 4.3% had histological or cytological confirmation respectively. Thoracoscopy (59.4%) was the most commonly used diagnostic procedure. Treatment utilisation: 53.6% chemotherapy; 35.5% radiotherapy; 9.4% extrapleural pneumonectomy (EPP); and 72.5% had palliative care involvement. There were no major differences in treatment utilisation between patients living in major cities and those in regional NSW (chemotherapy P = 0.42; radiotherapy P = 0.13 and palliative care P = 0.60), except for a higher rate of EPP in regional patients (16.7% vs 5.6%; P = 0.03). Median survival was 9.7 versus 12.3 months for city and regional patients respectively (P = 0.22)., Conclusion: Survival and treatment utilisation was not significantly different between MPM patients living in major cities and regional NSW, except for a higher rate of EPP in patients in regional NSW., (© 2012 The Authors; Internal Medicine Journal © 2012 Royal Australasian College of Physicians.)

Purpose: Malignant pleural mesothelioma (MPM) is a highly aggressive and symptomatic disease. We examined the relationship between health-related quality of life (HRQoL) and inflammatory markers, and the prognostic role of HRQoL in MPM patients., Methods: MPM patients from two parallel phase II studies (thalidomide alone or thalidomide with chemotherapy) were included. HRQoL was assessed at baseline using the modified Lung Cancer Symptom Scale (LCSS). Baseline inflammatory markers and cytokines were measured. Spearman correlation was used to examine the relationship between inflammatory markers and HRQoL measures. The prognostic value of the HRQoL domains was examined using Cox proportional hazard model., Results: Sixty-three patients were included: median age 61 years (range 44-79); 82% male; 77% Eastern Cooperative Oncology Group (ECOG) performance status 0-1; 44% epithelial histology subtype. Baseline systemic symptoms of anorexia and fatigue, the summation symptoms of overall symptomatic distress, interference with normal activity and global QoL and the aggregate score of total LCSS score were all associated with elevated neutrophil-to-lymphocyte ratio, C-reactive protein and vascular endothelial growth factor levels at baseline (rho ≥ 0.25; p < 0.05). Baseline anorexia, fatigue, cough, dyspnoea, pain, overall symptomatic distress, interference with normal activity, global QoL and total LCSS score were all significantly related to survival (p < 0.05) after adjusting for established prognostic factors (age, gender, histological subtype and performance status) and treatment effect., Conclusions: In conclusion, HRQoL seems to relate to a patient's systemic inflammatory status and is associated with survival in MPM patients.

Background: We hypothesized that in patients with malignant pleural mesothelioma (MPM) undergoing extrapleural pneumonectomy (EPP), high expression of excision repair cross complementation group 1 (ERCC1) and low expression of thymidylate synthase (TS) are associated with prolonged survival., Patients and Methods: Consecutive patients undergoing EPP at our institutions were reviewed. Tissue microarrays were constructed using five 1-mm cores per patient. TS and ERCC1 protein expression was evaluated by immunohistochemical techniques. The average percentage scores from evaluable cores were assessed and the median score was used to divide the group. Overall survival (OS) from the time of surgery was determined by the Kaplan-Meier method and results were compared by the log-rank test., Results: Eighty patients were included: median age, 58 years; 79% men; 76% epithelial and 24% biphasic subtypes; 25% and pathologic stage I/II and 73% stage III/IV. The median OS was 18.2 months (80% deceased at the censor date). Nineteen patients received neoadjuvant chemotherapy; 2 patients received chemotherapy with adjuvant intent and 28 patients received palliative chemotherapy. The median score was 10.2% for TS and 35% for ERCC1. There was no correlation between TS expression and OS (13.7 vs. 21.6 months for low and high levels, respectively; P = .32). There was a trend between high ERCC1 expression and longer OS (27.6 vs. 10.3 months; P = .06)., Conclusion: In this series of patients with MPM undergoing EPP, TS expression was not associated with prolonged survival, but there was a trend for longer survival in patients with high ERCC1 expression., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Introduction: We aimed to examine the prognostic values of established risk factors and to validate the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) in an independent series of patients with malignant pleural mesothelioma (MPM)., Patients and Methods: A total of 148 patients who applied for compensation at the Dust Diseases Board from 2007 to 2009 were included in this study. Overall survival was determined by the Kaplan-Meier method, and NLR was defined as the absolute neutrophil divided by the lymphocyte count. The prognostic value of the variables was examined by using Cox regression analysis, and all factors were entered into a multivariate model to determine their independent effect., Results: The patient characteristics were median age of 73 years; 93% men; 59% epithelial subtype; median NLR of 3.5 at diagnosis (n = 79); median overall survival of 10.6 months. The following variables were predictive of longer overall survival in univariate analysis: younger age, epithelial subtype, lower tumor stage, low white cell count, low platelet count, low hemoglobin level, and low NLR. Multivariate analysis confirmed that nonepithelial vs. epithelial subtype (hazard ratio [HR], 3.0; P < .001), tumor stage (HR, 1.6; P < .001), hemoglobin level difference ≥10 vs. <10 (HR, 2.0; P = .03), no chemotherapy vs. use of chemotherapy (HR, 2.4; P < .001), and NLR ≥3 vs. <3 (HR, 2.2; P < .01) were independently associated with prognosis., Conclusions: Apart from previously recognized factors, such as histosubtype, tumor stage, and hemoglobin level difference, NLR, an index of systemic inflammation bears prognostic significance that shows that a snapshot of immune status is able to convey important prognostic information., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The relationship between asbestos exposure and malignant mesothelioma (MM) has been well established. Despite bans on asbestos use in an increasing number of nations, the prolonged latency from exposure to diagnosis, and the ongoing presence and use of these dangerous fibres, have led to the increasing prevalence of this deadly disease worldwide. Whilst occupational contact has been implicated in the bulk of diagnosed cases over the past 50 years, a significant proportion of disease has been linked to para-occupational, domestic and environmental exposure. In this review, we will provide an update on the impact of historical and ongoing asbestos contact in both occupational and non-occupational settings. Furthermore, we will address the unresolved controversies surrounding the use of chrysotile asbestos, the effect of gender and genetics on development of this disease, childhood mesothelioma and co-aetiological factors including SV40 exposure., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

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.

Introduction: Survival after extrapleural pneumonectomy (EPP) is variable in patients with malignant pleural mesothelioma (MPM), and there are no validated prognostic factors that could be used preoperatively. We investigated the calretinin and D2-40 expression and the neutrophil-to-lymphocyte ratio (NLR), an index of systemic inflammation as potential preoperative prognostic factors., Methods: Consecutive patients who underwent EPP were included in this retrospective study. Potential prognostic factors such as age, gender, histological subtype, baseline laboratory parameters including NLR, and immunohistochemical staining for calretinin and D2-40 were evaluated. Overall survival (OS) from the date of surgery was determined by the Kaplan-Meier method. The prognostic value of the variables was examined using Cox regression, and significant factors (p < 0.05) were entered into a multivariate model to determine their independent effect., Results: A total of 85 patients were included: median age 58 years; 80% men; 77% epithelial and 23% biphasic MPM. The median OS was 19.7 months. The following variables were predictive of longer OS: female gender (p = 0.02), epithelial subtype (p = 0.04), low NLR (p < 0.01), and high calretinin score (p < 0.001). In a multivariate analysis, only NLR ≥3 (hazard ratio 1.79; 95% confidence interval: 1.04-3.07; p = 0.04) and calretinin score ≤33 versus more than 67% (hazard ratio 4.72; 95% confidence interval: 1.97-11.32; p < 0.01) remained independent predictors. The addition of calretinin score increased the explained variation by 10.1%., Conclusions: Both low calretinin expression and high NLR were independently associated with poor prognosis in patients with MPM undergoing EPP, and the calretinin score seemed to improve the accuracy of the prognostic model.

Aims: We previously established the use of a minimal panel of antibodies as sufficient to diagnose most epithelial malignant mesothelioma (MPM). We aimed to validate this approach and investigate the utility of a D2-40 antibody., Methods: A series of 80 MPM patients selected for surgery and 21 consecutive patients with pleural metastatic carcinoma were included. A minimal panel of antibodies, consisting of calretinin, BG8 and CD15, and D2-40 was investigated., Results: There were 61 epithelial and 19 biphasic MPM as well as 12 metastatic lung, six breast (5 ductal adenocarcinomas, 1 mixed ductal/lobular adenocarcinoma), two serous papillary ovarian carcinomas and one moderately differentiated colorectal adenocarcinoma. The sensitivity of positive calretinin labelling to confirm the diagnosis of MPM was 97.5%, while the 'diagnostic sensitivities' of lack of labelling for BG8 and CD15 were 91.3% and 97.5%, respectively. The use of calretinin, BG8 and CD15 resulted in correct classification in 97.5% of all MPMs. All MPM cases investigated showed at least focal positive D2-40 labelling., Conclusions: We have validated the usefulness of a minimal panel of antibodies with calretinin, BG8 and CD15 as the initial step to the diagnosis of MPM. D2-40 emerged as a helpful diagnostic tool for cases where our initial approach failed to conclusively diagnose MPM.

Malignant mesothelioma (MM) is an aggressive tumour affecting the mesothelial surfaces of the pleural and peritoneal cavities and, rarely, the pericardium and the tunica vaginalis testis. Despite a ban of asbestos in many industrialised nations, the present high incidence of MM is expected to continue, due to the long latency period between first asbestos exposure and occurrence of disease, making it an important health issue for the future. The diagnosis of MM can be difficult, both from a clinical and pathological perspective. It is not unusual for patients to undergo several medical investigations without definitive diagnosis early in their course of illness. Understandably, there is intense interest in the discovery of markers that can be assessed in pleural effusions, histological specimens, and serum to assist with the difficult early diagnosis of MM. Considering the primary aetiological role of asbestos, there is theoretically an easily identifiable target population for screening with a biomarker with adequate sensitivity and specificity or with a combination of biomarkers. In this review we focus on biomarkers that have been examined in the setting of either early diagnosis of MM in symptomatic patients or screening of asbestos-exposed individuals.

Introduction: Histological subtype is an established prognostic factor in malignant pleural mesothelioma (MPM). We retrospectively investigated the accuracy of classifying histological subtype on diagnostic biopsies and examined the impact of different diagnostic procedures on the outcome., Methods: Consecutive patients with histologically confirmed MPM who underwent extrapleural pneumonectomy (EPP) from 1994 to 2009 were included. Patient records were reviewed, and the initial diagnoses of histological subtype were obtained. The archival EPP specimens were reviewed by a panel of pathologists. The histological subtype obtained at review was compared with the initial diagnosis., Results: Eighty-five patients underwent EPP. Two patients achieved a pathological complete response after neoadjuvant chemotherapy, leaving 83 patients to be included in this review. Different diagnostic methods were used before EPP: 81% thoracoscopy; 7% thoracotomy; 11% computed tomography-guided procedure; and 1% other. Patients determined to have an epithelial subtype (n = 64) at EPP were diagnosed correctly at initial diagnostic biopsy in 84% of cases, whereas patients considered to have a biphasic subtype (n = 19) at EPP were diagnosed correctly at diagnostic biopsy in 26% of cases. The sensitivity and specificity of diagnostic biopsy for epithelial MPM was 93% and 31%, respectively. The overall subtype misclassification rate was 20%. Biopsy by thoracotomy was most accurate in subtype classification (83%) compared with thoracoscopy (74%) and computed tomography-guided procedure (44%)., Conclusions: The determination of histological subtype from a diagnostic biopsy is difficult due to sampling error, but an adequate specimen obtained from surgical biopsy increases the accuracy of subtype classification compared with radiological-guided biopsies.

Aims: Tissue microarray (TMA) technology has been utilised for assessment of cancers including malignant pleural mesothelioma (MPM). Given the intralesional heterogeneity of MPM, it is questionable if TMAs can adequately represent MPMs. We here investigate the validity of TMAs for MPM., Methods: TMAs were constructed from at least five cores for each of 80 archival tumours processed by two centres between 1994 and 2009. The percentage of cases correctly subtyped on TMAs compared with whole sections, in relation to the number of cores analysed, was calculated. Immunohistochemical labelling for calretinin and D2-40 was performed on TMAs and whole sections. To evaluate the validity of quantitative immunohistochemistry, percentages of positive cells were recorded and two-way analysis of variance (ANOVA) performed., Results: Five cores were assessable for 91% of patients. Four cores were sufficient to reach concordance with the whole-section result in 98% of cases for calretinin and 99% for D2-40. The correlation of the quantitative scores between the whole section and TMA cores was statistically significant (D2-40, rho = 0.84, p < 2.2e-16; calretinin, rho = 0.65, p = 7.9e-11). Neither the origin nor age of the blocks affected the results., Conclusion: If a minimum of four cores is used, TMA is an appropriate method for immunohistochemistry in MPM.

Purpose: Asbestos-induced chronic inflammation is implicated in the pathogenesis of malignant mesothelioma (MM). We have investigated blood neutrophil-to-lymphocyte ratio (NLR), an index of systemic inflammation, as a prognostic factor in MM patients., Experimental Design: Patients with MM who had systemic therapy at participating institutes were studied. Potential prognostic factors such as age, gender, performance status, histologic subtype, and baseline laboratory parameters, including NLR, were analyzed. Overall survival from commencement of therapy was determined by the Kaplan-Meier method. Multivariate analyses using Cox Regression model were performed with significant factors (P ≤ 0.05) to determine their independent effect., Results: A total of 173 MM patients undergoing systemic therapy including 119 patients receiving first-line therapy and 54 patients receiving second- or third-line therapy were included in this retrospective evaluation. Forty-two percent of patients had an elevated NLR at baseline. The following variables were predictive of survival: female gender (P = 0.044), epithelioid histologic subtype (P < 0.001), baseline white blood cell count less than 8.3 × 10⁹/L (P = 0.008), baseline platelet count 400 × 10⁹/L or less (P = 0.05), and NLR of 5 or less (P < 0.001). After multivariate analysis, histologic epithelioid subtype [hazard ratio (HR) = 2.0; 95% confidence interval (CI) = 1.3-2.9; P = 0.001], and NLR less than 5 (HR = 2.7; 95% CI = 1.8-3.9; P < 0.001) remained independent predictors. The 1-year survival rate was 60% versus 26%, whereas the 2-year survival rate was 34% versus 10% for NLR less than 5 and 5 or greater, respectively. In the separate analyses of chemotherapy-naive and previously treated patient groups, NLR was an independent predictor of survival in both groups., Conclusion: Our results indicate that NLR is an independent predictor of survival for patients with MM undergoing systemic therapy., (©2010 AACR.)

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., (© 2010 The Authors. Internal Medicine Journal © 2010 Royal Australasian College of Physicians.)