Incidence and mortality from malignant mesothelioma 1982-2020 and relationship with asbestos exposure: the Australian Mesothelioma Registry.

OBJECTIVES: Malignant mesothelioma is an uncommon cancer associated with asbestos exposure, predominantly occupational. Asbestos has been banned in Australia since 2003 but mesothelioma has a long latency and incident cases continue to present. The Australian Mesothelioma Registry was incepted to collect systematic data about incidence and mortality alongside asbestos exposure. METHODS: Benefiting from the Australian national system of cancer notification, all incident cases of mesothelioma in all states and territories are fast-tracked and notified regularly. Notified patients are contacted asking for consent to collect exposure information, initially by postal questionnaire and subsequently by telephone interview. Age-standardised annual incidence rates and mortality rates were calculated. Asbestos exposure was categorised as occupational, non-occupational, neither or, both; and as low, or high, probability of exposure. RESULTS: Mesothelioma incidence appears to have peaked. The age-standardised incidence rates have declined steadily since the early 2000s (peaking in males at 5.9/100 000 and in all-persons at 3.2/100 000), driven by rates in males, who comprise the majority of diagnosed cases. Rates in women have remained fairly stable since that time. Age-standardised mortality rates have followed similar trends. Mesothelioma remains the most common in those aged over 80 years. Nearly all (94%) cases were linked with asbestos exposure (78% occupational in men; 6.8% in women). CONCLUSIONS: With effective control of occupational asbestos use, the decline in age-standardised incidence and death rates has occurred. Incidence rates among women, in whom occupational asbestos exposure is rarely detectable, remain unchanged, pointing to the role of household and /or environmental asbestos exposure.

New Insights on Diagnostic Reproducibility of Biphasic Mesotheliomas: A Multi-Institutional Evaluation by the International Mesothelioma Panel From the MESOPATH Reference Center.

INTRODUCTION: The 2015 WHO classification of tumors categorized malignant mesothelioma into epithelioid, biphasic (BMM), and sarcomatoid (SMM) for prognostic relevance and treatment decisions. The survival of BMM is suspected to correlate with the amount of the sarcomatoid component. The criteria for a sarcomatoid component and the interobserver variability between pathologists for identifying this component are not well described. In ambiguous cases, a "transitional" (TMM) subtype has been proposed but was not accepted as a specific subtype in the 2015 WHO classification. The aims of this study were to evaluate the interobserver agreement in the diagnosis of BMM, to determine the nature and the significance of TMM subtype, and to relate the percentage of sarcomatoid component with survival. The value of staining for BRCA-1-associated protein (BAP1) and CDKN2A(p16) fluorescence in situ hybridization (FISH) were also assessed with respect to each of the tumoral components. METHODS: The study was conducted by the International Mesothelioma Panel supported by the French National Cancer Institute, the network of rare cancer (EURACAN) and in collaboration with the International Association for the Study of Lung Cancer (IASLC). The patient cases include a random group of 42 surgical biopsy samples diagnosed as BMM with evaluation of SMM component by the French Panel of MESOPATH experts was selected from the total series of 971 BMM cases collected from 1998 to 2016. Fourteen international pathologists with expertise in mesothelioma reviewed digitally scanned slides (hematoxylin and eosin - stained and pan-cytokeratin) without knowledge of prior diagnosis or outcome. Cases with at least 7 of 14 pathologists recognizing TMM features were selected as a TMM group. Demographic, clinical, histopathologic, treatment, and follow-up data were retrieved from the MESOBANK database. BAP1 (clone C-4) loss and CDKN2A(p16) homozygous deletion (HD) were assessed by immunohistochemistry (IHC) and FISH, respectively. Kappa statistics were applied for interobserver agreement and multivariate analysis with Cox regression adjusted for age and gender was performed for survival analysis. RESULTS: The 14 panelists recorded a total of 544 diagnoses. The interobserver correlation was moderate (weighted Kappa = 0.45). Of the cases originally classified as BMM by MESOPATH, the reviewers agreed in 71% of cases (385 of 544 opinions), with cases classified as pure epithelioid in 17% (93 of 544), and pure sarcomatoid in 12% (66 of 544 opinions). Diagnosis of BMM was made on morphology or IHC alone in 23% of the cases and with additional assessment of IHC in 77% (402 of 544). The median overall survival (OS) of the 42 BMM cases was 8 months. The OS for BMM was significantly different from SMM and epithelioid malignant mesothelioma (p < 0.0001). In BMM, a sarcomatoid component of less than 80% correlated with a better survival (p = 0.02). There was a significant difference in survival between BMM with TMM showing a median survival at 6 months compared to 12 months for those without TMM (p < 0.0001). BAP1 loss was observed in 50% (21 of 42) of the total cases and in both components in 26%. We also compared the TMM group to that of more aggressive patterns of epithelioid subtypes of mesothelioma (solid and pleomorphic of our large MESOPATH cohort). The curve of transitional type was persistently close to the OS curve of the sarcomatoid component. The group of sarcomatoid, transitional, and pleomorphic mesothelioma were very close to each other. We then considered the contribution of BAP1 immunostaining and loss of CDKN2A(p16) by FISH. BAP1 loss was observed in 50% (21 of 41) of the total cases and in both component in 27% of the cases (11 of 41). There was no significant difference in BAP1 loss between the TMM and non-TMM groups. HD CDKN2A(p16) was detected in 74% of the total cases with no significant difference between the TMM and non-TMM groups. In multivariate analysis, TMM morphology was an indicator of poor prognosis with a hazard ratio = 3.2; 95% confidence interval: 1.6 - 8.0; and p = 0.003 even when compared to the presence of HD CDKN2A(p16) on sarcomatoid component (hazard ratio = 4.5; 95% confidence interval: 1.2 - 16.3, p = 0.02). CONCLUSIONS: The interobserver concordance among the international mesothelioma and French mesothelioma panel suggests clinical utility for an updated definition of biphasic mesothelioma that allows better stratification of patients into risk groups for treatment decisions, systemic anticancer therapy, or selection for surgery or palliation. We also have shown the usefulness of FISH detection of CDKN2A(p16) HD compared to BAP1 loss on the spindle cell component for the separation in ambiguous cases between benign florid stromal reaction from true sarcomatoid component of biphasic mesothelioma. Taken together our results further validate the concept of transitional pattern as a poor prognostic indicator.

An RNAi-based screen reveals PLK1, CDK1 and NDC80 as potential therapeutic targets in malignant pleural mesothelioma.

This corrects the article DOI: 10.1038/bjc.2017.85.

An RNAi-based screen reveals PLK1, CDK1 and NDC80 as potential therapeutic targets in malignant pleural mesothelioma.

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.

Restoring expression of miR-16: a novel approach to therapy for malignant pleural mesothelioma.

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.

Facts and fiction: premalignant lesions of lung tissues.

Lung cancer is now the leading cause of death from cancer in Australia. Most patients are diagnosed with late-stage disease. Although diagnosis at pre-invasive stages could theoretically improve outcomes, mooted precursor lesions are often asymptomatic and often undetectable by non-invasive investigations. Nonetheless, they merit study to identify early and essential molecular steps involved in lung carcinoma pathogenesis, with the aim of developing therapies targeted against one or more such steps. Some lung cancers appear to develop via a series of progressive morphological changes with correlating molecular alterations, but others seem to arise in histologically normal epithelium, and these differences may reflect anatomically and functionally distinct epithelial compartments of the respiratory tract. Pre-invasive precursor lesions recognised by the World Health Organization (WHO) include squamous metaplasia with dysplasia and carcinoma in situ, atypical adenomatous hyperplasia, and diffuse idiopathic pulmonary neuroendocrine cell hyperplasia. Other lesions that likely represent pre-invasive lesions, but which are not currently WHO-listed, include human papillomavirus (HPV)-related respiratory papillomatosis and mesothelioma in situ. No single cancer stem cell marker has been identified. Field cancerisation plays an important role in lung cancer development, and includes the spread of pre-invasive clones along the respiratory epithelium or the occurrence of multiple separate foci of pre-invasive abnormalities such as squamous dysplasia and carcinoma in situ.In addition to well-characterised step-wise progression in squamous cell carcinomas and some adenocarcinomas, alternative pathways exist, and are currently being investigated. In addition, molecular techniques, including miRNA screening on blood samples or cytology samples--such as sputum samples--may become clinically relevant and more accurate in predicting lung cancer progression.

Unusual presentation of pulmonary tumor thrombotic microangiopathy with no detectable primary tumor.

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare condition characterized by the presence of diffuse thrombotic microthrombi and fibrocellular intimal proliferation in the pulmonary vasculature. Its development is linked to the presence of pulmonary tumor microemboli (PTM) and should be suspected in patients with unexplained dyspnea, especially in the presence of adenocarcinoma. PTTM presents in a similar fashion to respiratory disease such as pulmonary embolism, pulmonary hypertension or pneumonia and is usually only diagnosed post-mortem. We report a case of PTTM identified ante-mortem by bronchial biopsy in an 82-year-old woman presenting with a clinical picture of atypical pneumonia. Autopsy confirmed PTTM, from an unknown primary neoplasm.

Gene transfer to ovine corneal endothelium.

PURPOSE: Modification of a donor cornea by gene therapy has potential to modulate irreversible rejection, the major cause of corneal graft failure. The sheep is a useful model for the human in this respect, as ovine endothelial cells are amitotic. The aim of the study was to investigate the ability of various non-viral and viral agents to transfer a reporter gene to ovine corneal endothelium. METHODS: The non-viral agents Transfectin-10, Transfectin-20, Transfectin-50, SuperFect, Effectene and CLONfectin were used to deliver the reporter gene, Escherichia coli lacZ, to ovine corneal endothelium in vitro. A Herpes simplex virus-1 and an adenoviral vector each encoding E. coli lacZ were similarly tested. Infected corneas were organ-cutured for up to 7 days in vitro to allow transfection efficiency, duration of gene expression and toxicity attributable to each vector to be compared. RESULTS: Scattered single or clusters of endothelial cells expressing the reporter gene were observed after transfection with CLONfectin, Transfectin-10, Transfectin-20 and Transfectin-50. SuperFect and Effectene were virtually ineffective. At best, the absolute number of infected cells per endothelial monolayer after 3 or 7 days of organ culture was estimated as < 0.01%. The Herpes simplex virus-1 vector also failed to transduce ovine corneal endothelium efficiently. In contrast, transfection rates of up to 70% of endothelial cells were observed with the adenoviral vector. CONCLUSION: Non-viral vectors and Herpes simplex virus-1 are unlikely to be suitable for gene therapy of corneal endothelium, because the efficiency of transfection is low compared with the rates achieved with adenoviral vectors.

Prolongation of sheep corneal allograft survival by ex vivo transfer of the gene encoding interleukin-10.

BACKGROUND: Modification of a donor cornea by gene therapy ex vivo has potential to modulate irreversible rejection, the major cause of corneal graft failure. Our aim was to transfer the gene encoding mammalian IL-10 to ovine donor corneas and to determine subsequent orthotopic corneal allograft survival in an outbred sheep model. METHODS: The replicative capacity of ovine corneal endothelium was determined by autoradiography after deliberate injury. A replication-defective adenovirus was used to deliver the lacZ reporter gene to ovine corneas and transfected corneas were organ-cultured in vitro to allow transfection efficiency, duration of reporter gene expression, and toxicity attributable to the vector to be determined. A cDNA encoding full-length ovine IL-10 was cloned into an adenoviral vector that was used to transfect donor corneas ex vivo before transplantation. Orthotopic penetrating corneal transplantation was performed in outbred sheep. RESULTS: Sheep corneal endothelium was found to be essentially amitotic. Transfection of > 70% corneal endothelial cells was achieved with the viral vector and expression was maintained for 28 days in vitro. IL-10 mRNA was detectable in transfected, organ-cultured corneas for 21 days in vitro. Donor corneas transfected with cDNA encoding IL-10 showed significantly prolonged survival after penetrating keratoplasty (median 55 days, range 19 > or =300 days) compared with control corneas (median 20.5 days, range 18-32 days, P=0.011). CONCLUSION: Local gene therapy-mediated expression of the immunomodulatory cytokine IL-10 has the potential to reduce the incidence of corneal graft rejection and to prolong corneal allograft survival.

Endothelial cell loss after phacoemulsification: relation to preoperative and intraoperative parameters.

PURPOSE: To evaluate the effect of the location of the corneoscleral tunnel incision as well as preoperative and intraoperative parameters on total and localized endothelial cell loss. SETTING: Department of Ophthalmology, Humboldt-University of Berlin, Berlin, Germany. METHODS: Fifty consecutive patients scheduled for routine cataract surgery were selected prospectively for this clinical trial. Preoperatively, the axial length, anterior chamber depth, lens thickness, and astigmatism were measured. Phacoemulsification time and relative energy as well as total surgical time were recorded. With a specular microscope, endothelial cell counts were determined centrally, superiorly, and temporally preoperatively and 6 weeks and 6 and 12 months postoperatively. RESULTS: After 12 months, the mean overall central endothelial cell loss in all eyes was 8.5%. The mean endothelial cell loss was 11.9% in the lateral quadrant and 11.4% in the superior quadrant. There were no significant differences between superior and temporal surgical approaches in intraoperative parameters of phacoemulsification time, relative intensity of phacoemulsification, and surgical time. There were no significant differences in central endothelial cell loss or in the area localized in the quadrant of the positions of the corneal surgical site. The only risk factors found significant for higher endothelial cell loss were shorter axial length and longer phacoemulsification time. CONCLUSIONS: The location of corneoscleral incisions for phacoemulsification can be chosen according to the preoperative astigmatism without inducing additional adverse effects on the corneal endothelium. Shorter eyes have a significantly higher risk for greater endothelial cell loss.