Cases Of Malignant Pleural Mesothelioma Research Articles

Mesothelin methylation, soluble mesothelin related protein levels and inflammation profiling in workers chronically exposed to naturally occurring asbestos fibers

Exposure to asbestiform fibers, including chrysotile and amphibole, is carcinogenic, causing malignant pleural mesothelioma (MPM) when inhaled. Some populations globally face Naturally Occurring Asbestos (NOA) exposure, leading to MPM cases like in Biancavilla, Italy, from Fluoro-edenite (FE) contamination. Studies show NOA exposure causes epigenetic changes, focusing on mesothelin methylation, an MPM marker, and altered inflammation, emphasizing the health risks of FE and asbestos. This research, conducted from February 2022 to October 2022, studied 125 construction workers from Biancavilla and 125 controls from 40 km away without Biancavilla work history. With at least ten years in construction and no respiratory conditions, participants underwent medical assessments and gave blood samples for analysis, including inflammation markers, mesothelin methylation, and soluble mesothelin-related protein levels. The results showed similar demographics but differing inflammation and methylation levels in exposed workers, suggesting long-term cellular changes. Pearson correlation showed intricate biomarker relationships. Significant inflammatory differences were found between FE exposed and non-exposed workers, indicating potential health impacts from FE. This raises concerns for communities like Biancavilla, emphasizing the importance of extensive epigenetic research for public health.

LAG3 is an independent prognostic biomarker and potential target for immune checkpoint inhibitors in malignant pleural mesothelioma: a retrospective study

BackgroundLymphocyte-activation gene 3 (LAG3) is an immune checkpoint receptor; novel LAG3 immune checkpoint inhibitors (ICIs) exhibit therapeutic activity in melanoma. The role of LAG3and ICIs of LAG3 are unknown in malignant pleural mesothelioma (MPM). This study aimed to uncover the prognostic landscape of LAG3 in multiple cancers and investigate the potential of using LAG3 as an ICIs target in patients with MPM.MethodsWe used The Cancer Genome Atlas (TCGA) cohort for assessing mRNA expression and our cohort for immunohistochemical expression. TCGA cohort were analyzed using the Wilcoxon rank-sum test to compare mRNA expression between normal and tumor tissues in multiple cancers. We used 86 MPM cases from TCGA and 38 MPM cases from our cohort to analyze the expression of LAG3 in tumor-infiltrating lymphocytes. The mean LAG3 mRNA expression was set as the cut-off and samples were classified as positive/negative for immunohistochemical expression. Overall survival (OS) of patients with MPM was determined using the Kaplan–Meier method based on LAG3 mRNA and immunohistochemical expression. OS analysis was performed using the multivariate Cox proportional hazards model. The correlation of LAG3 expression and mRNA expression of tumor immune infiltration cells (TIICs) gene markers were estimated using Spearman correlation. To identify factors affecting the correlation of LAG3 mRNA expression, a multivariate linear regression model was performed.ResultsLAG3 mRNA was associated with prognosis in multiple cancers. Elevated LAG3 mRNA expression was correlated with a better prognosis in MPM. LAG3 expression was detected immunohistochemically in the membrane of infiltrating lymphocytes in MPM. LAG3 immunohistochemical expression was correlated with a better prognosis in MPM. The multivariate Cox proportional hazards model revealed that elevated LAG3 immunohistochemical expression indicated a better prognosis. In addition, LAG3 mRNA expression was correlated with the expression of various gene markers of TIICs, the most relevant to programmed cell death 1 (PD-1) with the multivariate linear regression model in MPM.ConclusionsLAG3 expression was correlated with prognosis in multiple cancers, particularly MPM; LAG3 is an independent prognostic biomarker of MPM. LAG3 regulates cancer immunity and is a potential target for ICIs therapy. PD-1 and LAG3 inhibitors may contribute to a better prognosis in MPM.Trial registrationThis study was registered with UMIN000049240 (registration day: August 19, 2022) and approved by the Institutional Review Board (approval date: August 22, 2022; approval number: 2022–0048) at Tokyo Women’s Medical University.

Safety and efficacy of helical tomotherapy following lung-sparing surgery in locally advanced malignant pleural mesothelioma

PurposeTo assess the value of radiation therapy (RT) with helical tomotherapy (HT) in the management of locally advanced malignant pleural mesothelioma (MPM) receiving no or lung-sparing surgery.MethodsConsecutive MPM cases not undergoing extrapleural pneumonectomy and receiving intensity-modulated (IM) HT were retrospectively evaluated for local control, distant control, progression-free survival (PFS), and overall survival (OS). Impact of age, systemic treatment, RT dose, and recurrence patterns was analyzed by univariate and multivariate analysis. As a secondary endpoint, reported toxicity was assessed.ResultsA total of 34 localized MPM cases undergoing IMHT were identified, of which follow-up data were available for 31 patients. Grade 3 side effects were experienced by 26.7% of patients and there were no grade 4 or 5 events observed. Median PFS was 19 months. Median OS was 20 months and the rates for 1‑ and 2‑year OS were 86.2 and 41.4%, respectively. OS was significantly superior for patients receiving adjuvant chemotherapy (p = 0.008).ConclusionIMHT of locally advanced MPM after lung-sparing surgery is safe and feasible, resulting in satisfactory local control and survival. Adjuvant chemotherapy significantly improves OS. Randomized clinical trials incorporating modern RT techniques as a component of trimodal treatment are warranted to establish an evidence-based standard of care pattern for locally advanced MPM.

Mesothelin expression remodeled the immune-matrix tumor microenvironment predicting the risk of death in patients with malignant pleural mesothelioma.

The combination of immunobiological agents with immune checkpoint proteins is a promising treatment for malignant pleural mesothelioma (MPM). Mesothelin and anti-PD-L1 antibody-drug conjugates specifically target malignant neoplastic cells, inhibit the migration and invasion of neoplastic cells, and restore the immune landscape. In this study, we confirmed the importance of mesothelin and examined the relationship between mesothelin and the immune landscape of the tumor microenvironment (TME) in two MPM cohorts. The discovery cohort included 82 MPM cases. Tissue microarray slides were generated, and samples were processed for hematoxylin & eosin staining, immunohistochemistry, and immunofluorescence assays. The relationship between mesothelin, biomarkers of histogenesis, histological aggressiveness, PD-L1, immune cells (CD4, CD8, CD20, CD68), and collagen type I and type V fibers was evaluated by quantitative digital analyses. The outcome was the survival time until death from disease recurrence. The exploratory cohort included 87 malignant mesothelioma (MESO) patients from The Cancer Genome Atlas database. Most patients were male (70.7%) with a history of asbestos exposure (53.7%) and with the epithelioid subtype (89%). Surgical resection was performed in 85.4% of patients, and 14.6% received chemotherapy; 59.8% of patients died from disease extension to the mediastinum. Low tumor mesothelin expression was associated with tumor necrosis and nuclear grade 1, whereas high mesothelin expression was significantly associated with the epithelioid histotype and high density of T cells CD8+, macrophages CD68+, and collagen type I fibers. Cox multivariate analysis showed a high risk of death for non-operated patients [hazard ratio (HR), 3.42 (1.15-10.16)] with low tumor mesothelin levels [HR, 2.58 (1.09-6.10)] and high PD-L1 and low infiltration of T cells CD4+ [HR, 3.81 (1.58-9.18)]. In the exploratory cohort, low mesothelin and high COL1A1 and COL5A1 expression were associated with poor overall survival. Tumor mesothelin expression associated with the TME immune landscape predicts the risk of death for patients with MPM and could be a new target for immunotherapy in MPM.

Analysis of clinicopathological features of 68 cases of malignant pleural mesothelioma

Objective: To analyze the clinicopathological characteristics of diffuse malignant pleural mesothelioma (MPM), and explore the diagnostic methods in order to improve the early diagnosis rate. Methods: In January 2019 to January 2022, the clinical features, auxiliary examination and immunohistochemical results of 68 cases of MPM were analyzed retrospectively. The pathogenic features, histopathological morphology and the expression of related antibodies including Calretinin (CR), D2-40 and WT-1 were summarized. Results: Among the 68 patients, 40 male (58.82%), 28 female (41.18%), male to female ratio was 1.43%, median age was 58 years old; 50% of patients in Dayao County, epithelial mesothelioma 59 cases (86.76%), occurred in right chest in 39 cases (57.35%), left chest in 25 cases (36.76%), and 4 cases in both sides (5.89%). The most common initial clinical manifestations were pleural effusion (95.59%), chest pain (36.75%), chest tightness and shortness of breath (30.88%). The main imaging findings were pleural effusion in 49 cases (98.00%) and pleural thickening in 46 cases (92.00%). MPM tumor cells often expressed Calretinin, CK5/6, WT1 and D2-40, while TTF-1, NapsinA and CEA, the main markers differentiated from lung adenocarcinoma were negative. Serum CYFRA21-1 and CEA have high value in differential diagnosis of benign and malignant pleural effusions. Conclusion: Diffuse MPM has diverse histological and cytological morphology, which needs to be differentiated from a variety of diseases. Correct diagnosis of diffuse MPM through immunohistochemistry requires the combined application of a group of Mesothelium related antibodies.

KRAS Mutations Are Associated with Shortened Survival in Patients with Epithelioid Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive malignancy of the pleural surface that includes three major histologic subtypes, epitheliod, sarcomatoid and biphasic. Epithelioid mesothelioma is usually associated with better prognosis. The genetic mechanisms driving MPM, the possible target mutations and the correlation with overall survival remain largely unsettled. We performed target exome sequencing in 29 cases of MPM aimed at identifying somatic mutations and, eventually, their correlation with phenotypic traits and prognostic significance. We found that KRAS mutations, occurring in 13.7% of cases, were associated with shortened median survival (7.6 versus 32.6 months in KRAS wild-type; p = 0.005), as it was the occurrence of any ≥3 mutations (7.6 versus 37.6 months; p = 0.049). Conversely, the presence of KDR single nucleotide polymorphism p.V297I (rs2305948) resulted in a favorable variable for survival (NR versus 23.4 months; p = 0.026). With the intrinsic limitations of a small number of cases and patient heterogeneity, results of this study contribute to the characterization of the mutation profile of MPM and the impact of selected somatic mutations, and possibly KDR polymorphism, on prognosis.

Malignant pleural mesothelioma characteristics and outcomes: A SEER-Medicare analysis.

Pleural mesothelioma is rare cancer linked to asbestos exposure. Previous research has indicated that female individuals have better survival than male individuals, but this has never been examined in the Surveillance, Epidemiology, and End Results(SEER)-Medicare database. Malignant pleural mesothelioma cases diagnosed from 1992 to 2015 were queried from the linked SEER-Medicare database. Multivariable logistic regression was used to assess the clinical and demographic factors associated with sex. A multivariable Cox proportional hazards model and propensity matching methods were used to assess sex differences in overall survival (OS) while accounting for potential confounders. Among 4201 patients included in the analysis, 3340 (79.5%) were males and 861 (20.5%) females. Females were significantly older, with more epithelial histology than males were, and had significantly better OS, adjusted for confounders (adjusted hazard ratio, 0.83, 95% confidence interval: 0.76-0.90). Other variables independently associated with improved survival included younger age at diagnosis, having a spouse/domestic partner, epithelial histology, lower comorbidity score, and receipt of surgery or chemotherapy. The study describes sex differences in mesothelioma occurrence, treatment, and survival and is the first to examine SEER-Medicare. It provides directions for future research into potential therapeutic targets.

Serum Extracellular Vesicle-Derived microRNAs as Potential Biomarkers for Pleural Mesothelioma in a European Prospective Study.

Malignant pleural mesothelioma (MPM) is an aggressive cancer with a dismal prognosis. Early therapeutic interventions could improve patient outcomes. We aimed to identify a pattern of microRNAs (miRNAs) as potential early non-invasive markers of MPM. In a case-control study nested in the European Prospective Investigation into Cancer and Nutrition cohort, we screened the whole miRNome in serum extracellular vesicles (EVs) of preclinical MPM cases. In a subgroup of 20 preclinical samples collected five years prior MPM diagnosis, we observed an upregulation of miR-11400 (fold change (FC) = 2.6, adjusted p-value = 0.01), miR-148a-3p (FC = 1.5, p-value = 0.001), and miR-409-3p (FC = 1.5, p-value = 0.04) relative to matched controls. The 3-miRNA panel showed a good classification capacity with an area under the receiver operating characteristic curve (AUC) of 0.81 (specificity = 0.75, sensitivity = 0.70). The diagnostic ability of the model was also evaluated in an independent retrospective cohort, yielding a higher predictive power (AUC = 0.86). A signature of EV miRNA can be detected up to five years before MPM; moreover, the identified miRNAs could provide functional insights into the molecular changes related to the late carcinogenic process, preceding MPM development.

Blood cell DNA methylation biomarkers in preclinical malignant pleural mesothelioma: The EPIC prospective cohort.

Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer mainly caused by asbestos exposure. Specific and sensitive noninvasive biomarkers may facilitate and enhance screening programs for the early detection of cancer. We investigated DNA methylation (DNAm) profiles in MPM prediagnostic blood samples in a case-control study nested in the European Prospective Investigation into Cancer and nutrition (EPIC) cohort, aiming to characterise DNAm biomarkers associated with MPM. From the EPIC cohort, we included samples from 135 participants who developed MPM during 20 years of follow-up and from 135 matched, cancer-free, controls. For the discovery phase we selected EPIC participants who developed MPM within 5 years from enrolment (n=36) with matched controls. We identified nine differentially methylated CpGs, selected by 10-fold cross-validation and correlation analyses: cg25755428 (MRI1), cg20389709 (KLF11), cg23870316, cg13862711 (LHX6), cg06417478 (HOOK2), cg00667948, cg01879420 (AMD1), cg25317025 (RPL17) and cg06205333 (RAP1A). Receiver operating characteristic (ROC) analysis showed that the model including baseline characteristics (age, sex and PC1wbc) along with the nine MPM-related CpGs has a better predictive value for MPM occurrence than the baseline model alone, maintaining some performance also at more than 5 years before diagnosis (area under the curve [AUC] < 5 years=0.89; AUC 5-10 years=0.80; AUC >10 years=0.75; baseline AUC range=0.63-0.67). DNAm changes as noninvasive biomarkers in prediagnostic blood samples of MPM cases were investigated for the first time. Their application can improve the identification of asbestos-exposed individuals at higher MPM risk to possibly adopt more intensive monitoring for early disease identification.

Assessment of miR-103a-3p in leukocytes-No diagnostic benefit in combination with the blood-based biomarkers mesothelin and calretinin for malignant pleural mesothelioma diagnosis.

Malignant pleural mesothelioma (MPM) is a cancer associated with asbestos exposure and its diagnosis is challenging due to the moderate sensitivities of the available methods. In this regard, miR-103a-3p was considered to increase the sensitivity of established biomarkers to detect MPM. Its behavior and diagnostic value in the Mexican population has not been previously evaluated. In 108 confirmed MPM cases and 218 controls, almost all formerly exposed to asbestos, we quantified miR-103-3a-3p levels in leukocytes using quantitative Real-Time PCR, together with mesothelin and calretinin measured in plasma by ELISA. Sensitivity and specificity of miR-103-3a-3p alone and in combination with mesothelin and calretinin were determined. Bivariate analysis was performed using Mann-Whitney U test and Spearman correlation. Non-conditional logistic regression models were used to calculate the area under curve (AUC), sensitivity, and specificity for the combination of biomarkers. Mesothelin and calretinin levels were higher among cases, remaining as well among males and participants ≤60 years old (only mesothelin). Significant differences for miR-103a-3p were observed between male cases and controls, whereas significant differences between cases and controls for mesothelin and calretinin were observed in men and women. At 95.5% specificity the individual sensitivity of miR-103a-3p was 4.4% in men, whereas the sensitivity of mesothelin and calretinin was 72.2% and 80.9%, respectively. Positive correlations for miR-103a-3p were observed with age, environmental asbestos exposure, years with diabetes mellitus, and glucose levels, while negative correlations were observed with years of occupational asbestos exposure, creatinine, erythrocytes, direct bilirubin, and leukocytes. The addition of miR-103a-3p to mesothelin and calretinin did not increase the diagnostic performance for MPM diagnosis. However, miR-103a-3p levels were correlated with several characteristics in the Mexican population.

Sarcomatoid malignant pleural mesothelioma treated with nivolumab: A case series.

Immune checkpoint therapy (ICT) with nivolumab has been widely used to treat malignant pleural mesothelioma (MPM) since clinical trials confirmed its efficacy. However, only a few clinical trials have been conducted for the treatment of sarcomatoid MPM, which is a rare histological type of MPM. Additionally, clinical reports of sarcomatoid MPM are scarce. Therefore, the benefits and risks of nivolumab treatment for sarcomatoid MPM remain unclear. The present report describes the treatment of 3 cases of sarcomatoid MPM (all 3 were men) with nivolumab monotherapy. In all three cases, nivolumab was effective despite variations in the duration of treatment, although side effects were observed in 2 patients. Programmed death ligand 1 (PD-L1) expression was positive in all 3 cases. In particular, the patient with the highest PD-L1 expression had the most rapid response of the 3 patients, and the effect lasted as long as those of the other 2, despite receiving the smallest number of doses of nivolumab. It has been reported that sarcomatoid MPM tends to respond poorly to chemotherapy and express higher levels of PD-L1 than epithelial MPM; thus, ICT may be necessary in these cases. This case series suggests that ICT with nivolumab is a promising treatment option for sarcomatoid MPM.

EP07.01-015 Multimodality Imaging for Characterization, Classification, and Staging of Malignant Pleural Mesothelioma, Focusing on MR Imaging

Malignant pleural mesothelioma (MPM) is the most common primary malignancy of the pleura and the prognosis for MPM patients is still dismal despite the progress of treatment. Early diagnosis at a potentially curative stage is crucial to prolong patient survival and reduce morbidity and mortality. Here, we review the imaging findings of surgically confirmed MPM cases at preoperative CT and MR imaging.

Improving outcomes in malignant pleural mesothelioma in an integrated health care system.

BackgroundMalignant pleural mesothelioma (MPM) is a rare and aggressive tumor that should be managed by an experienced surgical and multidisciplinary group. Our objective was to determine the impact of proficient surgeons and MPM bi-disciplinary review on outcomes of patients with MPM.MethodsThrough this cohort study, electronic medical records of 368 adult patients with MPM from 1/1/2009 to 12/31/2020 were reviewed and compared before and after MPM surgeries were regionalized to specialized surgeons and bi-disciplinary review of MPM patient treatment options. We used the Kaplan-Meier method and log-rank tests to compare survival rates by period, by treatment type, and by stage. Patients were followed from cancer diagnosis date until they died or end of study follow-up, whichever occurred first. We also conducted Cox proportional hazards regression model to examine the overall survival (OS) with adjustments for age, histology, stage, and Charlson comorbidity index (CCI).ResultsDespite similar staging, more patients received any MPM directed treatment from 2015–2020 compared with those patients from 2009–2014. Specifically, there was an increase in patients who received pleurectomy/decortication (PD) from 2015–2020 compared to those who received PD in 2009–2014. Patients with similar age, CCI, stage, and histology had an increase in OS of 12 months with multimodality therapy (surgery, systemic therapy, +/− radiation) compared to those patients who received no treatment.ConclusionsConsolidating mesothelioma surgery to a specialized surgical team and regular bi-disciplinary review of MPM cases to determine appropriate multimodality therapy, increases the incorporation of surgical treatments in the management of patients with MPM.

A phase 1, first-in-human study of IK-930, an oral TEAD inhibitor targeting the Hippo pathway in subjects with advanced solid tumors.

TPS3168 Background: The transcriptional enhanced associate domain (TEAD) family of proteins are key transcription factors in the Hippo signaling pathway and play a critical role in cell proliferation, migration, angiogenesis, and apoptosis. Published literature demonstrates that approximately 10% of all solid tumors present with a dysregulated Hippo pathway and subsequent constitutive activation of TEAD, which drives gene expression involved in cell growth and pro-survival signaling. Deficiencies in neurofibromin 2 (NF2), a key regulator of the Hippo pathway, can be found in over 40% of cases of malignant pleural mesothelioma (MPM). NF2 deficiency also occurs at high incidence in meningiomas, cholangiocarcinomas, thymoma, and schwannoma. Gene fusions in in Yes1 associated transcriptional regulator (YAP1) or WW domain containing transcription regulator 1 (TAZ/WWTR1) are also indicative of high TEAD activation and can be seen in solid tumors including epithelioid hemangioendothelioma (EHE) where &gt;90% of cases are associated with TAZ-CAMTA1 gene fusion and the other 10% of cases have YAP1/TFE3 gene fusion. IK-930 is a novel, selective, small molecule inhibitor of TEAD that prevents palmitate binding and thereby disrupts aberrant TEAD-dependent transcription. In preclinical models, IK-930 demonstrates antitumor activity in mouse xenograft models with Hippo pathway genetic alterations. IK-930 is under clinical investigation as an oral agent in patients with advanced solid tumors. Methods: This is a phase 1, first-in-human, open-label, multicenter dose escalation and dose expansion study to evaluate the safety and tolerability of IK-930 as monotherapy, and to determine the recommended phase 2 dose (RP2D) and/or maximum tolerated dose (MTD) using the Bayesian Optimal Interval Design (BOIN). Eligible participants in dose escalation include adult patients with advanced or metastatic solid tumors for whom there is no available therapy known to confer clinical benefit. Patients will receive escalating doses of IK-930 starting at 25mg daily. IK-930 will be administered initially in a 28-day cycle and will progress to a 21-day cycle when evaluated as safe and well-tolerated. A dose expansion phase will follow with four genetically defined cohorts of solid tumors, including: NF2-deficient MPM (Cohort 1), other NF2-deficient solid tumors agnostic to tumor type (Cohort 2), EHE with TAZ-CAMTA1 or YAP1-TFE3 gene fusions (Cohort3), and solid tumors with YAP1/TAZ gene fusions agnostic to tumor type (Cohort 4). Primary endpoints include evaluation of dose-limiting toxicities and treatment-emergent adverse events and determination of RP2D and/or MTD. Secondary objectives include evaluation of preliminary antitumor activity by RECIST 1.1 and pharmacokinetic (PK) parameters. The study began in January 2022 and is currently enrolling. Clinical trial information: NCT05228015.

Malignant pleural mesothelioma in Brazil: An analysis of public databases between 2000 and 2017.

e20597 Background: malignant mesothelioma is a rare tumor with about 31,000 new cases diagnosed annually worldwide. Malignant pleural mesothelioma (MPM) is recognized as an occupational cancer, and past exposure to asbestos represents its main risk factor. Little is known about the epidemiological and clinicopathological profile in developing countries. Methods: this is a cross-sectional study that analyzed the incidence and mortality rates and the clinicopathological profile of MPM in Brazil, from Brazilian public databases: Population-Based Cancer Registries (PBCRs - for incidence), Hospital Cancer Registry (HCR - for clinicopathological profile) and National Mortality Information System (SIM - for mortality). Results: In thirty PBCRs, from 23 of 26 states (average covered of 17% of the Brazilian population), 310 new MPM cases were reported, from 2000 to 2015. The mean age at diagnosis was 62.8 years. Incidence crude rate reached its maximum of 8.96 per 1.000.000 men in the 75-79 age group, and of 3.34 per 1.000.000 women in the 80+ age group. The clinicopathological profile registered in the HCR, from 2000 to 2017, showed a majority of men (70.2%), smoker/former smoker (62.7%) and alcohol users (58.2%). Regarding histology, 59% were described as mesothelioma, NOS (not otherwise specified), 30.6% as epithelioid, 7% as fibrous mesothelioma and 3.4% as biphasic. 54.4% were stage IV at diagnosis, 27.5% stage III and 18.1% stages I or II. A quarter of the patients received neither local nor systemic treatment. From 2000 to 2017 512 deaths related to MPM were registered in SIM database, an average of 28 deaths per year (mean age of death 63.7 years). The age-adjusted mortality rate remained statistically stable over all analyzed period. Conclusions: According to our study, most MPM patients in Brazil are elderly men, stage IV at diagnosis, with mesothelioma NOS. A considerable percentage do not receive any specific treatment for the disesase. Understanding the scenario of MPM in Brazil is important to design prevention, diagnosis and treatment strategies.

Occupations and geographical distribution of mesothelioma in Switzerland 1989–2018 – record linkage of an asbestos-exposed population with the Swiss National Cohort

We investigated the possibility of linking the data of the Swiss Laboratory for Particle Analysis (Silag), a valuable but incomplete data source in the field of asbestos-related diseases, to the Swiss National Cohort (SNC). With the resulting comprehensive dataset, we intended to provide a source for further research in the field. We also conducted preliminary analyses of data focusing on occupations and regional distribution of malignant pleural mesothelioma cases. Data of asbestos-exposed individuals available from the Silag were anonymously linked with the SNC by means of deterministic record linkage. From this linkage, data on occupation classified according to the international standard classification of occupations (ISCO) as well as the canton of residence in Switzerland could be retrieved. Of 838 eligible individuals from the Silag data, 788 (94.0%) could be linked to the SNC database, including 476 mesothelioma cases. In 340 cases of the latter, data on occupation and industries were available. Although the majority of them were blue-collar workers, a significant proportion (n = 44, 12.9%) had executive professions. The Canton of residence in 1990 was established in 430 of subjects with mesothelioma. A cluster could be identified in eastern Switzerland, especially in the canton of Glarus. It was possible to link the datasets to a large extent thereby creating a data source for further research. Of note, the linkage provided data on occupation of a selection of mesothelioma cases in Switzerland.

Asbestos Exposure in Patients with Malignant Pleural Mesothelioma included in the PRIMATE Study, Lombardy, Italy.

The PRIMATE study is an Italian translational research project, which aims to identify personalized biomarkers associated with clinical characteristics of malignant pleural mesothelioma (MPM). For this purpose, characteristics of MPM patients with different degrees of asbestos exposure will be compared to identify somatic mutations, germline polymorphism, and blood inflammatory biomarkers. In this framework, we assessed exposure to asbestos for 562 cases of MPM extracted from the Lombardy region Mesothelioma Registry (RML), for which a complete interview based on a standardized national questionnaire and histopathological specimens were available. Exposure assessment was performed: (1) through experts' evaluation (considered as the gold standard for the purpose of this study), according to the guidelines of the Italian National Mesothelioma Registry (ReNaM) and (2) using a job-exposure matrix (SYN-JEM) to obtain qualitative (ever/never) and quantitative estimates of occupational asbestos exposure (cumulative exposure expressed in fibers per mL (f/mL)). The performance of SYN-JEM was evaluated against the experts' evaluation. According to experts' evaluation, occupational asbestos exposure was recognized in 73.6% of men and 23.6% of women; furthermore, 29 men (7.8%) and 70 women (36.9%) had non-occupational exposure to asbestos. When applying SYN-JEM, 225 men (60.5%) and 25 women (13.2%) were classified as occupationally exposed, with a median cumulative exposure higher for men (1.7 f/mL-years) than for women (1.2 f/mL-years). The concordance between the two methods (Cohen’s kappa) for occupational exposure assessment was 0.46 overall (0.41 in men, and 0.07 in women). Sensitivity was higher in men (0.73) than in women (0.18), while specificity was higher in women (0.88) than in men (0.74). Overall, both methods can be used to reconstruct past occupational exposure to asbestos, each with its own advantages and limitations.

Investigation of pd-l1 (cd274), pd-l2 (pdcd1lg2), and ctla-4 expressions in malignant pleural mesothelioma by immunohistochemistry and real-time polymerase chain reaction methods.

Malignant pleural mesothelioma (MPM) is an aggressive malignant disease with apoor prognosis, which affects the surface mesothelium of the pleural cavity. Immune checkpoints are responsible for controlling the immune system to avoid autoimmunity and prevent tissue damage. In this study, we aimed to investigate the expression of cytotoxic T lymphocyte antigen-4 (CTLA-4), programmed death ligand 1 (PD-L1), and programmed death ligand 2 (PD-L2) immuno-control receptors in MPM patients and the relationship of the expression with tumour types and prognostic parameters. In this study, we evaluated 50 MPM cases. Immunohistochemically CTLA-4, PD-L1, and PD-L2 were detected by using monoclonal anti-CTLA-4, anti-PD-L1, and anti-PD-L2. Real-time polymerase chain reaction (RT-PCR) analysis was performed with the primers CTLA-4, PD-L1, and PD-L2. Statistically, no significant relation was determined between the PD-L1, PD-L2, and CTLA-4 expressions (immunohistochemical and RT-PCR methods) and the MPM histological type. Interestingly significant correlation was observed between the mean survival time and immunohistochemical PD-L2 expression; thus, long-term survival was observed in cases with PD-L2 expression. Programmed death ligand 1, PD-L2, and CTLA-4 expression were observed in some MPM cases, suggesting that treatments targeting immune checkpoints may be effective. Because immunohistochemical expression of PD-L2 is associated with better prognosis, it may provide useful clues in the follow-up of patients.

Anticancer agent α-sulfoquinovosyl-acylpropanediol enhances the radiosensitivity of human malignant mesothelioma in nude mouse models.

Malignant pleural mesothelioma (MPM) is a highly malignant disease that develops after asbestos exposure. Although the number of MPM cases is predicted to increase, no effective standard therapies have been established. The novel radiosensitizer α-sulfoquinovosyl-acylpropanediol (SQAP) enhances the effects of γ-radiation in human lung and prostate cancer cell lines and in animal models. In this study, we explored the radiosensitizing effect of SQAP and its mechanisms in MPM. The human MPM cell lines MSTO-211H and MESO-4 were implanted subcutaneously into the backs and thoracic cavities of immunodeficient KSN/Slc mice, then 2 mg/kg SQAP was intravenously administered with or without irradiation with a total body dose of 8 Gy. In both the orthotopic and ectopic xenograft murine models, the combination of irradiation plus SQAP delayed the implanted human MSTO-211H tumor growth. The analysis of the changes in the relative tumor volume of the MSTO-211H indicated a statistically significant difference after 8 Gy total body combined with 2 mg/kg SQAP, compared to both the untreated control (P = 0.0127) and the radiation treatment alone (P = 0.0171). After the treatment in each case, immunostaining of the harvested tumors revealed decreased cell proliferation, increased apoptosis and normalization of tumor blood vessels in the SQAP- and irradiation-treated group. Furthermore, hypoxia-inducible factor (HIF) 1 mRNA and protein expression were decreased, indicating reoxygenation in this group. In conclusion, SQAP improved hypoxic conditions in tumor tissue and may elicit a radiosensitizing effect in malignant mesothelioma models.

Thoracic mesenchymal malignant tumors and programed cell death ligand-1 status: Clinicopathologic and prognostic analysis of eight pulmonary sarcomatoid carcinomas and eight malignant mesotheliomas.

BackgroundThe current study aimed to evaluate the significance of clinicopathological factors, particularly the immunohistochemistry of programed cell death ligand‐1 (PD‐L1), in eight cases each of pulmonary sarcomatoid carcinoma (PSC) and malignant pleural mesothelioma (MPM) at our hospital.MethodsFrom January 2004 to December 2020, a total of 16 consecutive patients (eight with PSC and eight with MPM diagnosed via surgical resection or biopsy) were included in this study. After retrospectively reviewing the patient characteristics, the associations between PD‐L1 status and age, sex, stage, histological type, and prognosis were investigated.ResultsPD‐L1‐positive staining was observed in four (50%) PSC cases and one (12.5%) MPM case. Among the four PD‐L1‐positive PSC cases, two showed high PD‐L1 expression in the vimentin‐positive sarcomatoid compartment. Moreover, among those with PSC, two survived for about 10 years, whereas the others died within 5 years. No clear correlation was found between PD‐L1 expression and prognosis. Among the patients with MPM, four survived for more than 2 years, with the longest being 9 years. Among MPM cases who received nivolumab, one patient with positive PD‐L1 staining in the sarcomatoid survived, whereas the other with negative PD‐L1 staining did not.ConclusionThe present study showed that sarcomatoid carcinoma had a higher PD‐L1 expression compared to non‐small‐cell lung cancer and that both PSC and MPM tended to exhibit PD‐L1 positivity in the sarcomatoid compartment. Moreover, while immune checkpoint inhibitors may somewhat prolong the prognosis of both tumors, further studies with a larger cohort are necessary to confirm our results.