Occupational and non-occupational attributable risk of asbestos exposure for malignant pleural mesothelioma.

OBJECTIVES: To estimate the proportion of pleural mesothelioma cases that can be attributed to asbestos exposure in France including non-occupational exposure. METHODS: A population-based case-control study including 437 incident cases and 874 controls was conducted from 1998 to 2002. Occupational and non-occupational asbestos exposure was assessed retrospectively by two expert hygienists. ORs of pleural mesothelioma for asbestos-exposed subjects compared to non-exposed subjects, and population-attributable risk (ARp) of asbestos exposure were estimated using a conditional logistic regression. RESULTS: A clear dose-response relationship was observed between occupational asbestos exposure and pleural mesothelioma (OR=4.0 (99% CI 1.9 to 8.3) for men exposed at less than 0.1 f/mL-year vs. 67.0 (99% CI 25.6 to 175.1) for men exposed at more than 10 f/mL-year). The occupational asbestos ARp was 83.1% (99% CI 74.5% to 91.7%) for men and 41.7% (99% CI 25.3% to 58.0%) for women. A higher risk of pleural mesothelioma was observed in subjects non-occupationally exposed to asbestos compared to those never exposed. The non-occupational asbestos ARp for these subjects was 20.0% (99% CI -33.5% to 73.5%) in men and 38.7% (99% CI 8.4% to 69.0%) in women. When considering all kinds of asbestos exposure, ARp was 87.3% (99% CI 78.9% to 95.7%) for men and 64.8% (99% CI 45.4% to 84.3%) for women. CONCLUSIONS: Our study suggests that the overall ARp in women is largely driven by non-occupational asbestos exposure arguing for the strong impact of such exposure in pleural mesothelioma occurrence. Considering the difficulty in assessing domestic or environmental asbestos exposure, this could explain the observed difference in ARp between men and women.

Two cases of aggressive nontumoral folliculotropic mycosis fungoides with visceral involvement.

Mycosis fungoides (MF) is the most common type of primary cutaneous T-cell lymphoma (CTCL), and folliculotropic MF (FMF) is one clinical variant of classic MF. MF generally has a good prognosis with an indolent clinical course, but for FMF greater therapeutic resistance is suggested. Visceral involvement is very rare in these two clinical forms. We report two exceptional cases of FMF with pulmonary and hepatic involvement. Five years after their initial diagnoses, patient 1 presented with a pulmonary localization of his FMF, and patient 2 with liver involvement, without lymph node or T-cell clones in the blood. These two patients had FMF corresponding to stage T2N0M1B0. These two cases highlight the aggressiveness of this rare variant of MF. They suggest that the T lymphocytes found in the folliculotropic form of CTCL could be characterized by greater visceral tropism. They raise the question of the molecular and functional characteristics of these T lymphocytes, and the possibility of a common target in the hair follicles and certain organs. Studies have shown that chemokine receptors are likely to be involved in the skin tropism that characterizes CTCL. These two cases show the aggressiveness of FMF and point to the interest in comparing the molecular characteristics of T lymphocytes in the folliculotropic and nonfolliculotropic forms of CTCL.

Update on gene fusions and the emerging clinicopathological landscape of peritoneal and pleural mesotheliomas and other neoplasms.

BACKGROUND: Mesothelioma is a rare and aggressive malignant neoplasm arising from mesothelial cells, which occasionally manifests recurrent fusions. EWSR1/FUS-CREB, YY1, MAP3K8, NR4A3, and ALK-rearranged proliferations have been reported in limited series with no clear histological or clinical correlations, limiting clinicians' ability to assess prognosis and integrate these new entities into therapeutic decisions. The aim of this study was to better characterize these rearranged proliferations histologically, molecularly, and clinically. METHODS: Clinical, pathological, and comprehensive transcriptome and mutation data were collected for each case. RESULTS: A total of 41 tumors were included, encompassing 7 ALK, 10 MAP3K8, 4 NR4A3, 8 ESWR1/FUS::ATF1, 8 EWSR1::YY1, and 4 SUFU-fused cases. We found a female predominance, except for cases harboring NR4A3 and SUFU; and most patients were around 60 years of age, but those harboring ALK or EWSR1/FUS::ATF1 gene fusions were younger. Each group exhibited distinct histological, immunohistochemical, molecular features, and oncological courses. Specifically, MAP3K8 and ALK presented PAX8+ papillary proliferations, ESWR1/FUS::ATF1 and EWSR1::YY1 displayed angiomatoid fibrous histiocytoma-like patterns, while SUFU showcased 'tissue culture'-like spindle cell proliferation. Poor prognosis factors were the pleural site, male sex, Ki67 ≥10%, and ESWR1/FUS::ATF1 or SUFU gene fusions. CONCLUSIONS: This study significantly broadens the spectrum of mesothelial tumors associated with fusions, offering insight into novel epithelioid (mesothelial) proliferations with distinctive histological appearances, molecular profiles, and prognoses to guide adapted treatments for patients.

Malignant pleural mesothelioma: from the bench to the bedside.

Optimal management of malignant pleural mesothelioma (MPM), which is mainly based on patient characteristics and clinical stage, is not clearly defined yet, although detailed, practical guidelines for these patients have been proposed by some scientific societies. Translational research, in the field of this disease, is currently in progress and different molecular oncogenic pathways leading to the growth and progression of MPM have been characterized with recent pharmaceutical developments. However, further in-depth analysis still needs to be done for a more advanced deciphering of the step-by-step process leading from early increased mesothelial cell proliferation to invasive mesothelioma, from which we are expecting the development of definitively effective therapy. Thus, this review is an overview of the recent advances in the biology of MPM and their potential therapeutic applications in the field of MPM diagnosis and treatment.

Evolution of pleural cancers and malignant pleural mesothelioma incidence in France between 1980 and 2005.

The evolution of pleural cancers and malignant pleural mesothelioma incidence in France between 1980 and 2005 was analysed using data derived from the French network of cancer registries (FRANCIM) and the French National Mesothelioma Surveillance Program (PNSM). Mesothelioma proportions in pleural cancers were calculated by diagnosis year in the 1980-2000 period. Our results suggest that the incidences of pleural cancer and mesothelioma levelled off in French men since 2000 and continued to increase in French women. A decrease of the annual pleural cancer incidence average in men was noticed (-3.4% of annual rate of change) between 2000 and 2005. The proportion of pleural cancers that were mesothelioma was unchanged between 1980 and 2003 with an average of 86%. The age standardised incidence rate of pleural mesothelioma remained relatively stable between 1998 and 2005 with a slight falling trend. For women, the age standardised incidence rate of pleural cancers and mesothelioma increased during the period 1998-2005. Additionally, the proportion of pleural cancers that were mesothelioma increased during the same period of time. Finally, the increased trend observed in the incidence of pleural mesothelioma and cancers in women is credibly due to their under diagnosis in the 1980-1997 period. The comparison between the French incidence and the American and British ones shows that the decreasing trend in incidence of mesothelioma and pleural cancers in French men since 2000 is potentially associated with a lower amphibole consumption and by the implementation of safety regulations at work from 1977.

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

Malignant pleural mesothelioma (MPM) is a rare tumour but with increasing incidence and a poor prognosis. In 2008, the European Respiratory Society/European Society of Thoracic Surgeons Task Force brought together experts to propose practical and up-to-dated guidelines on the management of MPM. To obtain an earlier and reliable diagnosis of MPM, the experts recommend performing thoracoscopy, except in cases of pre-operative contraindication or pleural symphysis. The standard staining procedures are insufficient in approximately 10% of cases. Therefore, we propose using specific immunohistochemistry markers on pleural biopsies. In the absence of a uniform, robust and validated staging system, we advice use of the most recent TNM based classification, and propose a three step pre-treatment assessment. Patient's performance status and histological subtype are currently the only prognostic factors of clinical importance in the management of MPM. Other potential parameters should be recorded at baseline and reported in clinical trials. MPM exhibits a high resistance to chemotherapy and only a few patients are candidates for radical surgery. New therapies and strategies have been reviewed. Because of limited data on the best combination treatment, we emphasise that patients who are considered candidates for a multimodal approach should be included in a prospective trial at a specialised centre.

[Cranial fasciitis of childhood]. / Fasciite crâniale.

OBJECTIVE: To describe the clinical and pathological features of cranial fasciitis of childhood, and to review and compare this case with those of international literature. METHODS: We report a case of cranial fasciitis of childhood located on the face of a 13-month-old boy. A complete review was performed from the database "Pub Med", looking for the key words "head and neck inflammatory myofibroblastic tumour", "nodular fasciitis", "cranial fasciitis of childhood". RESULTS: Cranial fasciitis is benign rapidly growing fibroblastic tumour, belonging to the group of nodular fasciitis, and has a predilection for the head and neck region of young children. This tumour is highly cellular and often show striking erosion of bone often misdiagnosed as a sarcoma. Surgery with adequate resection margin is the best treatment. There is no tendency for local recurrence. CONCLUSION: Positive pathological diagnosis of cranial fasciitis is uncommon and may be difficult.

Incidence and survival of peritoneal malignant mesothelioma between 1989 and 2015: A population-based study.

BACKGROUND: Peritoneal malignant mesothelioma is a rare disease for which few population-based studies are available. The aim of this study was to describe the evolution of the incidence and survival of peritoneal malignant mesothelioma in France between 1989 and 2015, using data derived from the French network of cancer registries. METHODS: Age world-standardized incidence rates and overall survival were calculated using data from 16 French cancer registries. Log-linear Poisson regression analysis was used to estimate the average annual percentage change in incidence rates. Overall survival was performed using age-adjusted Cox proportional hazards model. RESULTS: In French men, the incidence has increased quietly over the reporting period from 0.07 to 0.10 with a maximum of 0.16 per 100,000 persons-years in 2001-2003. For women, the increase in incidence has been lower than for men over the period 1989-2015, ranging from 0.04 to 0.11. A better prognosis was associated with a diagnosis made after 2000 (HR = 1.76; p = 0.013), the epithelioid histological type (p = 0.003), and the fact of being a woman, which has a 5-year risk of death half that of men (HR = 0.55; p = 0.001), regardless of age, diagnosis period or histology. CONCLUSION: Our results are similar to those currently available for other countries. In France, peritoneal mesothelioma remains a rare and fatal cancer with a small increase in the incidence rate since 1989 and a median survival of 1 year; it seemed to develop equally in women and men over this period of time.

Integrative and comparative genomic analyses identify clinically relevant pulmonary carcinoid groups and unveil the supra-carcinoids.

The worldwide incidence of pulmonary carcinoids is increasing, but little is known about their molecular characteristics. Through machine learning and multi-omics factor analysis, we compare and contrast the genomic profiles of 116 pulmonary carcinoids (including 35 atypical), 75 large-cell neuroendocrine carcinomas (LCNEC), and 66 small-cell lung cancers. Here we report that the integrative analyses on 257 lung neuroendocrine neoplasms stratify atypical carcinoids into two prognostic groups with a 10-year overall survival of 88% and 27%, respectively. We identify therapeutically relevant molecular groups of pulmonary carcinoids, suggesting DLL3 and the immune system as candidate therapeutic targets; we confirm the value of OTP expression levels for the prognosis and diagnosis of these diseases, and we unveil the group of supra-carcinoids. This group comprises samples with carcinoid-like morphology yet the molecular and clinical features of the deadly LCNEC, further supporting the previously proposed molecular link between the low- and high-grade lung neuroendocrine neoplasms.

EGFR and PDGFR differentially promote growth in malignant epithelioid mesothelioma of short and long term survivors.

BACKGROUND: Malignant pleural mesothelioma (MPM) is an asbestos related tumour difficult to detect early and treat effectively. Asbestos causes genetic modifications and cell signalling events that favour the resistance of MPM to apoptosis and chemotherapy. Only a small number of patients, approximately 10%, survive more than 3 years. The aim of our study was to assess possible differences within signalling pathways between short term survivors (survival <3 years; STS) and long term survivors (survival >3 years; LTS) of MPM. METHODS: 37 antibodies detecting proteins engaged in cell signalling pathways, enforcing proliferation, antiapoptosis, angiogenesis and other cellular activities were investigated by tissue microarray (TMA) technology. RESULTS: Epidermal growth factor receptor (EGFR) was expressed stronger in LTS whereas platelet derived growth factor receptor (PDGFR) signalling was more abundant in STS. Expression of TIE2/Tek, a receptor for tyrosine kinases involved in angiogenesis, was differentially regulated via PDGFR and thus is more important in STS. Antiapoptosis was upregulated in STS by signal transducer and activator of transcription 1 (STAT1)-survivin and related molecules, but not in LTS. Our study provides novel insights into the regulatory mechanisms of signalling pathways in MPM, which differentially promote tumour growth in LTS and STS. CONCLUSION: We have demonstrated that small scale proteomics can be carried out by powerful linkage of TMA, immunohistochemistry and statistical methods to identify proteins which might be relevant targets for therapeutic intervention.

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.

[Compensation of malignant mesothelioma as an occupational disease in Lower Normandy, from 1995 to 2002]. / L'indemnisation du mésothéliome malin professionnel en Basse-Normandie entre 1995 et 2002.

BACKGROUND: Despite the close relation between occupational exposure to asbestos and malignant mesothelioma, the compensation of this disease is still far from being the rule. The objective of this study is to assess the compensation process of all the cases of occupational mesothelioma recorded by the regional mesothelioma registry between September 1995 and August 2002, and to make suggestions for improvement of the compensation of future cases. METHODS: Lifetime exposure to asbestos was assessed for each of the 141 mesothelioma cases observed in Lower Normandy during this time period, and 105 cases could be related to a possible, probable, or very probable occupational exposure to this mineral. Data about notification and compensation of these occupational diseases were gathered with the help of all health insurance organisms concerned. RESULTS: Except for five cases in which insurance conditions did not allow any compensation, compensation of occupational mesothelioma occurred in 85% of the cases. This high rate was probably the result of the existence of an early asbestos industry in this region, and of the particular awareness of the Norman population about asbestos-related diseases, as well as of the epidemiological follow-up of mesothelioma in Lower Normandy. When notified for compensation, all cases but one were actually compensated, and the lag-time between notification and compensation proved to decrease since 1995, with an average delay reaching 91,1 days in 2002. Patients who did not report their disease were older than those who did, and the lack of knowledge of medical practitioners about compensation procedures seems to be an important matter in this issue. CONCLUSION: In order to improve the rate of compensation of occupational malignant mesothelioma cases, information about the usual occupational origin of the disease should be delivered systematically to the general practitioner of each patient. This could be done by pathologists, when they diagnose malignant mesothelioma, and/or by medical examiners when sickness benefits are sought, or even by the epidemiological center of death causes (INSERM, CépiDc), for the beneficiaries of patients who died from malignant mesothelioma.

[Epidemiology, molecular biology, diagnostic and therapeutic strategy of malignant pleural mesothelioma in 2007 - an update]. / Prise en charge dignostique et thérapeutique du mésothéliome pleural malin en 2007.

Malignant pleural mesothelioma (MPM) is a rare tumour due to occupational asbestos exposure. The incidence of MPM will continue to increase until 2020-2030. The incidence reaches 100 cases/million/year in occupationally exposed populations as opposed to 1 case/million/year in the general population, leading to 800 to 1,000 cases per year in France. The molecular carcinogenesis of MPM is incompletely understood but alterations to genes NF2, c-met, WT1 RASSF and p16 have been described. These genes are involved in cell invasion and motility, cell division and apoptosis control. Histological diagnosis remains difficult and depends on immunohistochemical analysis as described by the French Mesopath group. Clinical diagnosis relies on thoracoscopy and large pleural biopsies, with increasing use of CT-PET for the evaluation of disease extent. Therapeutic strategy includes prophylactic irradiation following drainage or thoracoscopy to prevent tumour nodule development along drainage channels and puncture sites. In selected patients, extensive extra-pleural pneumonectomy can be performed with curative intent. First line chemotherapy is based on a combination of pemetrexed and cisplatin that has demonstrated an improvement in overall survival and quality of life in phase 3 trials. Antiangiogenic agents such as bevacizumab (Avastatin) may be of interest but need to be tested in phase 3 trials. The Mesothelioma Avastatin Pemetrexed Study (MAPS) is ongoing, coordinated by the French Thoracic Cancer Intergroup (IFCT).

[Benign asbestos-related pleuropulmonary diseases]. / Affections pleuropulmonaires bénignes liées à l'amiante.

Among the non malignant diseases related to asbestos exposure, pleural plaques are the most frequent. Pleural effusion and diffuse pleural thickening, as well as asbestosis, are uncommon nowadays in asbestos-exposed screened populations. Despite the absence of any useful treatment, accurate diagnoses of these diseases are needed for two reasons: on the one hand in order to save patients from anxiety related to diagnostic and prognostic discrepancies, and on the other hand in order to ensure a proper attribution of the high social and financial compensations which are provided in France for asbestos affected patients. CT scan of the thorax is the most sensitive and specific tool for a precise diagnosis of these lesions, but it often displays minute abnormalities which may give rise to major diagnostic discordances, owing to the absence of any tomodensitometric reference in populations proved to be free from any asbestos exposure. There is a need to seek for a suitable standardization of imaging technique and interpretation, for a consensus in the characterization of CTscan abnormalities that warrant compensation, and for a careful medico-psychologic assistance for patients affected by asbestos-related benign diseases.

[Primitive metastasizing bronchial carcinoid with long survival]. / Carcinoïde bronchique d'emblée multimétastatique et survie prolongée. Une entité anatomo-clinique peu connue: place de l'imagerie fonctionnelle.

BACKGROUND: Metastatic bronchial carcinoid tumours are rare but some patients have a prolonged survival. A new functional imagery now makes it possible to supplement the assessment of the extent of disease. OBSERVATION: A 57 year old patient was referred for dyspnoea on exertion revealing an upper left lobar tumour, with carcinoid syndrome. The assessment enabled to find out a bronchial carcinoid tumour with liver and bone metastases, highlighted by positron-emission tomography and pentetreotide SPECT. A chemotherapy proved to be ineffective and upper left lobectomy was carried out because of the risk of pulmonary atelectasis. The patient was treated by somatostatin analogues then underwent liver transcatheter arterial chemo-embolization. The patient was alive 44 months after diagnosis (56 months after first computed tomography). CONCLUSION: Metastatic bronchial carcinoid tumours are rare. They keep a metastatic potential, the histological type remaining the major prognosis factor. Carcinoid syndrome is suggestive. The assessment of extra-thoracic disease extent benefits by contribution of new functional imagery techniques such as the pentetreotide SPECT and positron-emission tomography. The management is essentially symptomatic since there is no effective chemotherapy. However survival can be prolonged, even in multimetastatic patients.

The French National Mesothelioma Surveillance Program.

OBJECTIVES: The French National Mesothelioma Surveillance Program (NMSP) was established in 1998 by the National Institute for Health Surveillance (InVS). Its objectives are to estimate the trends in mesothelioma incidence and the proportion attributable to occupational asbestos exposure, to help improve its pathology diagnosis, to assess its compensation as an occupational disease, and to contribute to research. METHODS: The NMSP records incident pleural tumours in 21 French districts that cover a population of approximately 16 million people (a quarter of the French population). A standardised procedure of pathological and clinical diagnosis ascertainment is used. Lifetime exposure to asbestos and to other factors (man made mineral fibres, ionising radiation, SV40 virus) is reconstructed, and a case-control study was also conducted. The proportion of mesothelioma compensated as an occupational disease was assessed. RESULTS: Depending on the hypothesis, the estimated number of incident cases in 1998 ranged from 660 to 761 (women: 127 to 146; men: 533 to 615). Among men, the industries with the highest risks of mesothelioma are construction and ship repair, asbestos industry, and manufacture of metal construction materials; the occupations at highest risk are plumbers, pipe-fitters, and sheet-metal workers. The attributable risk fraction for occupational asbestos exposure in men was 83.2% (95% CI 76.8 to 89.6). The initial pathologist's diagnosis was confirmed in 67% of cases, ruled out in 13%, and left uncertain in the others; for half of the latter, the clinical findings supported a mesothelioma diagnosis. In all, 62% applied for designation of an occupational disease, and 91% of these were receiving workers' compensation. CONCLUSIONS: The NMSP is a large scale epidemiological surveillance system with several original aspects, providing important information to improve the knowledge of malignant pleural mesothelioma, such as monitoring the evolution of its incidence, of high risk occupations and economic sectors, and improving pathology techniques.

Management of giant cell arteritis: Recommendations of the French Study Group for Large Vessel Vasculitis (GEFA).

PURPOSE: Management of giant cell arteritis (GCA, Horton's disease) involves many uncertainties. This work was undertaken to establish French recommendations for GCA management. METHODS: Recommendations were developed by a multidisciplinary panel of 33 physicians, members of the French Study Group for Large Vessel Vasculitis (Groupe d'étude français des artérites des gros vaisseaux [GEFA]). The topics to be addressed, selected from proposals by group members, were assigned to subgroups to summarize the available literature and draft recommendations. Following an iterative consensus-seeking process that yielded consensus recommendations, the degree of agreement among panel members was evaluated with a 5-point Likert scale. A recommendation was approved when ≥ 80% of the voters agreed or strongly agreed. RESULTS: The 15 retained topics resulted in 31 consensus recommendations focusing on GCA nomenclature and classification, the role of temporal artery biopsy and medical imaging in the diagnosis, indications and search modalities for involvement of the aorta and its branches, the glucocorticoid regimen to prescribe, treatment of complicated GCA, indications for use of immunosuppressants or targeted biologic therapies, adjunctive treatment measures, and management of relapse and recurrence. CONCLUSIONS: The recommendations, which will be updated regularly, are intended to guide and harmonize the standards of GCA management.

Effect of simian virus large T antigen expression on cell cycle control and apoptosis in rat pleural mesothelial cells exposed to DNA damaging agents.

Cell cycle progression and apoptosis are controlled by regulatory proteins, including p53, of which functional alterations are linked to carcinogenesis. Recently, malignant mesothelioma (MM), a primary tumour related to asbestos exposure, alternatively to post therapeutic radiations, has proven to be an important problem in oncogenesis. The p53 protein does not seem mutated or deleted in MM but a possible inactivation by binding to other proteins [mdm2; SV40 large T antigen (Tag)] has been suggested. The present work investigated cell cycle regulation in normal rat pleural mesothelial cells (RPMC) and in RPMC expressing Tag (RPMC-TSV40), under exposure to asbestos and radiations. In RPMC, these agents induced activation of cell cycle checkpoints located at G1/S and G2/M and/or mitosis but a lack of control at G1/S was found in RPMC-TSV40. A loss of G2/M control may account for the formation of micronuclei observed after exposure of RPMC-TSV40 to radiations. In RPMC-TSV40 the enhancement of abnormal mitoses and apoptosis after asbestos exposure, in comparison with RPMC, suggests a loss of mitotic control and a p53-independent mechanism of apoptosis. Thus Tag expression in mesothelial cells might have both adverse and beneficial effects by impairing the control of DNA integrity and enhancing apoptosis respectively.

Immunodetection of SV40 large T antigen in human central nervous system tumours.

BACKGROUND/AIMS: DNA sequences from Simian virus 40 (SV40) have been previously isolated from various human tumours of the central nervous system (CNS). This study aimed to investigate a series of tumours of the CNS for the expression of the SV40 large T antigen (Tag), which is an oncogenic protein of the virus. METHODS: A French series of 82 CNS tumours was investigated for Tag expression using a monoclonal antibody and immunohistochemistry. A Tag positive hepatocellular carcinoma cell line from transgenic mice and a kidney biopsy from a patient infected by SV40 were used as positive controls. RESULTS: None of the tumours (20 ependymomas, 20 glioblastomas, 12 oligodendrogliomas, three plexus choroid adenomas, two plexus choroid carcinomas, 15 meningiomas, and 10 medulloblastomas) contained SV40 Tag positive cells. CONCLUSIONS: The lack of SV40 Tag in 82 CNS tumours of various types is at variance with previous studies from different countries, and suggests that the virus may not be an important factor in CNS tumorigenesis, at least in French cases.