The genetic susceptibility in the development of malignant pleural mesothelioma

Mesothelioma among seamen: a systematic review and meta-analysis

OBJECTIVES

Navy personnel and seafarers live and work 24 h per day in the shipboard environment and they are exposed to asbestos fibers released into the confined spaces aboard ships. We conducted a systematic review and meta-analysis to quantify the mesothelioma risk of seamen working aboard ships, either commercial or naval vessels, as compared to that of the general population.

METHODS

We carried out a literature search in MEDLINE through PubMed and EMBASE, from inception to 31 December 2021, of all studies on seamen working aboard ships, either commercial or naval vessels, characterized by exposure to asbestos and providing mesothelioma risk estimates. The Newcastle-Ottawa Scale was used to assess the quality of the studies included. The pooled standardized mortality ratio (SMR) was computed across eligible studies. The study protocol was registered on PROSPERO and reporting followed the preferred reporting items for systematic reviews and meta-analyses guidelines.

RESULTS

A total of 10 studies published from 1990 to 2020 were considered eligible and included in the systematic review and meta-analysis. All the included studies were of good quality, with a median score of seven out of nine. Overall, there were 235 mesothelioma cases/deaths in the included studies versus 115.6 expected, with a pooled SMR of 2.11 (95% confidence intervals, 1.70-2.62), in the absence of a significant between-study heterogeneity ( I2  = 39%, P  = 0.11).

CONCLUSION

A more than double excess risk for mesothelioma among seamen working aboard ships emerged from our meta-analysis.

A Rare Presentation of Minimally Invasive Mesothelioma as a Large Tension Pneumothorax

Development of mesothelioma is associated with asbestos exposure. Common presentations are with pleural-based plaques invading the chest wall and/or pleural effusion on chest imaging. The intent of this case report is to describe a rare presentation of mesothelioma, which presented atypically as a large tension pneumothorax. A 93-year-old male presented with a history of dyspnea that started after a coughing episode. On physical examination he was hemodynamically stable, but was hypoxic requiring 2L of supplemental oxygen. Computed tomography of the chest revealed a large right tension pneumothorax. A chest tube was placed and connected to suction (-20cmH20), but he continued to have an unresolving air leak over the following 2-week period. Upon video-assisted thoracotomy there were no blebs or adhesions seen. Right apical wedge resection and talc pleurodesis were performed. Pathologic examination revealed an atypical mesothelial cell proliferation with minimal, focal invasion into the pulmonary parenchyma. Tumor spread along the visceral pleura was thought to be the underlying cause of the pneumothorax. The surgical margins were uninvolved by the tumor, and the patient was later discharged home in stable condition. This was a rare presentation of what could best be described as minimally invasive mesothelioma arising in a background of probable mesothelioma in situ, which presented atypically as a large tension pneumothorax. This case highlighted the importance of establishing a pathologic diagnosis from pleural effusion cytology and/or pleural biopsy in persons presenting with spontaneous pneumothorax, and the difficulty in confirming a pathologic diagnosis of early mesothelial neoplasia.

The association of genetic factors with serum calretinin levels in asbestos-related diseases

BACKGROUND

Asbestos exposure is associated with different asbestos-related diseases, including malignant mesothelioma (MM). MM diagnosis is confirmed with immunohistochemical analysis of several markers, including calretinin. Increased circulating calretinin was also observed in MM. The aim of the study was to determine if CALB2 polymorphisms or polymorphisms in genes that can regulate calretinin expression are associated with serum calretinin levels or MM susceptibility.

SUBJECTS AND METHODS

The study included 288 MM patients and 616 occupationally asbestos-exposed subjects without MM (153 with asbestosis, 380 with pleural plaques and 83 without asbestos-related disease). Subjects were genotyped for seven polymorphisms in CALB2, E2F2, MIR335, NRF1 and SEPTIN7 genes using competitive allele-specific polymerase chain reaction (PCR). Serum calretinin was determined with ELISA in 545 subjects. Nonparametric tests, logistic regression and receiver operating characteristic (ROC) curve analysis were used for statistical analysis.

RESULTS

Carriers of at least one polymorphic CALB2 rs889704 allele had lower calretinin levels (P = 0.036). Carriers of two polymorphic MIR335 rs3807348 alleles had higher calretinin (P = 0.027), while carriers of at least one polymorphic NRF1 rs13241028 allele had lower calretinin levels (P = 0.034) in subjects without MM. Carriers of two polymorphic E2F2 rs2075995 alleles were less likely to develop MM (odds ratio [OR] = 0.64, 95% confidence interval [CI] = 0.43-0.96, P = 0.032), but the association was no longer significant after adjustment for age (P = 0.093). Optimal serum calretinin cut-off values differentiating MM patients from other subjects differed according to CALB2, NRF1, E2F2, and MIR335 genotypes.

CONCLUSIONS

The results of presented study suggest that genetic variability could influence serum calretinin levels. These findings could contribute to a better understanding of calretinin regulation and potentially to earlier MM diagnosis.

The role of single nucleotide polymorphisms related to iron homeostasis in mesothelioma susceptibility after asbestos exposure: a genetic study on autoptic samples

Asbestos-related diseases still represent a major public health problem all over the world. Among them, malignant mesothelioma (MM) is a poor-prognosis cancer, arising from the serosal lining of the pleura, pericardium and peritoneum, triggered by asbestos exposure. Literature data suggest the key role of iron metabolism in the coating process leading to the formation of asbestos bodies, considered to be both protective and harmful. Two sample sets of individuals were taken into consideration, both residing in Broni or neighboring cities (Northwestern Italy) where an asbestos cement factory was active between 1932 and 1993. The present study aims to compare the frequency of six SNPs involved in iron trafficking, previously found to be related to protection/predisposition to MM after asbestos exposure, between 48 male subjects with documented asbestos exposure who died of MM and 48 male subjects who were exposed to asbestos but did not develop MM or other neoplastic respiratory diseases (Non-Mesothelioma Asbestos Exposed - NMAE). The same analysis was performed on 76 healthy male controls. The allelic and genotypic frequencies of a sub-group of 107 healthy Italian individuals contained in the 1000 genomes database were considered for comparison. PCR-multiplex amplification followed by SNaPshot mini-sequencing reaction was used. The findings presented in this study show that the allelic and genotypic frequencies for six SNP markers involved in iron metabolism/homeostasis and the modulation of tumor microenvironment are not significantly different between the two sample sets of MM and NMAE. Therefore, the SNPs here considered do not seem to be useful markers for individual susceptibility to mesothelioma. This finding is not in agreement with previous literature.

Assessment protocol of mesothelioma and relevance of SEM-EDS analysis through a case studies of legal medicine of Brescia (Italy)

INTRODUCTION

This study evaluates the assessment protocol that allows the correlation between the development of mesothelioma to a specific exposure, with particular focus on investigations with Scanning Electron Microscope with Energy Dispersion Spectroscopy.

METHODS

This retrospective study includes 80 subjects who died from mesothelioma in the period 2001-2019. A judicial autopsy was performed for each case to confirm cause of death and correlate the disease with specific asbestos exposure. In 28 cases investigations were carried out to determine the pulmonary load of the asbestos fibres and corpuscles in the lung tissue through microscopic investigations, in order to confirm the suspicion of occupational exposure.

RESULTS

Our data agree with the scientific literature reported, but it is interesting to underline how the present study uses a different systematic approach than others, which are mainly based on epidemiological and environmental studies without considering the lung content of fibres and corpuscles.

CONCLUSION

It would be desirable that the use of the microscopic analysis was introduced in the evaluation protocol: it should always be carried out if the suspicion of asbestos-related disease is raised and not only as a possible integration to the less expensive anamnestic evaluation, even more so if the work or personal history should be suggestive of exposure to asbestos fibres.

Case Report and Review of Literature: Familial Malignant Pleural Mesothelioma in a 39 Years Old Patient With an Inconclusive 18F-FDG PET/CT Result

Malignant pleural mesothelioma (MPM) is a rare yet aggressive neoplasm that was linked only to asbestos exposure for decades, although familial clusters were diagnosed with MPM without a known history of asbestos exposure most likely due to genetic susceptibility. Here, we describe a case of familial malignant mesothelioma in a 39 years old patient with a confirmed BAP1 mutation in addition to a known family history with the same mutation. The patient presented with progressive shortness of breath and recurrent pleural effusions and diagnosis was made through biopsies taken during uniportal Video-Assisted Thoracoscopic Surgery. After the inconclusive result of ¹⁸F-FDG PET/CT scan, subxiphoid uniportal Video-Assisted Thoracoscopic Surgery left pleural and laparoscopic peritoneal biopsies were obtained for staging and evaluating contralateral lung and peritoneal cavity. Finally, two important educational values should be acquired from this case: genetic predisposition and BAP1 tumor suppressor gene mutation might affect the age of presentation and overall prognosis of the disease. Also, ¹⁸F-FDG PET/CT scan may not be the best modality for staging and confirming the diagnosis of malignant pleural mesothelioma.

The influence of genetic variability in IL1B and MIR146A on the risk of pleural plaques and malignant mesothelioma

Background

Asbestos exposure is associated with the development of pleural plaques as well as malignant mesothelioma (MM). Asbestos fibres activate macrophages, leading to the release of inflammatory mediators including interleukin 1 beta (IL-1β). The expression of IL-1β may be influenced by genetic variability of IL1B gene or regulatory microRNAs (miRNAs). This study investigated the effect of polymorphisms in IL1B and MIR146A genes on the risk of developing pleural plaques and MM.

Subjects and methods

In total, 394 patients with pleural plaques, 277 patients with MM, and 175 healthy control subjects were genotyped for IL1B and MIR146A polymorphisms. Logistic regression was used in statistical analysis.

Results

We found no association between MIR146A and IL1B genotypes, and the risk of pleural plaques. MIR146A rs2910164 was significantly associated with a decreased risk of MM (OR = 0.31, 95% CI = 0.13–0.73, p = 0.008). Carriers of two polymorphic alleles had a lower risk of developing MM, even after adjustment for gender and age (OR = 0.34, 95% CI = 0.14–0.85, p = 0.020). Among patients with known asbestos exposure, carriers of at least one polymorphic IL1B rs1143623 allele also had a lower risk of MM in multivariable analysis (OR = 0.50, 95% CI = 0.28–0.92, p = 0.025). The interaction between IL1B rs1143623 and IL1B rs1071676 was significantly associated with an increased risk of MM (p = 0.050).

Conclusions

Our findings suggest that genetic variability of inflammatory mediator IL-1β could contribute to the risk of developing MM, but not pleural plaques.

Circulating Epigenetic Biomarkers in Malignant Pleural Mesothelioma: State of the Art and critical Evaluation

Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer, which originates from the mesothelial cells of the pleura and is associated with asbestos exposure. In light of its aggressive nature, late diagnosis and dismal prognosis, there is an urgent need for identification of biomarkers in easily accessible samples (such as blood) for early diagnosis of MPM. In the last 10 years, epigenetic markers, such as DNA methylation and microRNAs (miRNAs), have gained popularity as possible early diagnostic and prognostic biomarkers in cancer research. The aim of this review is to provide a critical analysis of the current evidences on circulating epigenetic biomarkers for MPM and on their translational potential to the clinical practice for early diagnosis and for prognosis.

North-south gradient of mesothelioma and asbestos consumption-production in the United States-Progresses since the 1st asbestos partial ban in 1973

BACKGROUND

Temporal trends and broad geographical distributions of asbestos use and the incidence of malignant mesothelioma (MM) in the US still need to be studied.

METHODS

Data on asbestos consumption and production between 1900 and 2015 and MM mortality and incidence rates between 1975 and 2015 in the US were examined. Spatial distributions of MM mortality and incidence rates and their association with climate zone were analyzed.

RESULTS

Decline of MM incidence and mortality rates in the US occurred about 20 years after the peak of asbestos consumption-production in 1973. There are apparent north-south (N-S) gradients in MM mortality and incidence rates in the US.

CONCLUSION

Recent decline of MM incidence and mortality rates in the US may be associated with reduced US asbestos consumption. N-S MM gradients between 1999 and 2015 were likely related to larger asbestos requirements in building materials in the northern states.

Impact of asbestos on public health: a retrospective study on a series of subjects with occupational and non-occupational exposure to asbestos during the activity of Fibronit plant (Broni, Italy)

The goal of this study is to understand more about the role of asbestos in causing human diseases, first of all mesothelioma, by investigating a large series of deaths due to asbestos-related diseases (ARDs). The main aim is to clarify if even very low amounts of asbestos can cause mesothelioma and other ARDs, as well as to find out if a different individual vulnerability can be important. This retrospective study included 188 subjects who died from asbestos related diseases in 2000-2017 in the area around Broni, Italy, where an important asbestos cement factory had been active from 1932 until 1993. In each case, a forensic autopsy has been performed. In order to perform the present study, the records were retrieved, including the clinical files, the autopsy, and the histological report. The statistical analysis performed showed that there was a significant relation between the cause of death (mesothelioma, lung cancer or asbestosis) and the kind of exposure (occupational, neighborhood or household), showing that all the subjects not exposed occupationally (and, therefore, exposed to lower amounts of asbestos) died from mesothelioma, whereas the individuals who used to work at the plant died also from other caused (asbestosis, lung cancer). Significant differences were highlighted examining the distribution of the causes of death according to the smoking habits. Moreover, among the mesothelioma patients, the survival time was shorter in the subjects with a neighborhood or household exposure than in the occupationally exposed individuals. The study provided meaningful data about the role of asbestos in causing human pathologies. In particular, the present data appear to support the hypothesis that even an exposure to a very little amount of asbestos can cause mesothelioma in hypersusceptible subjects (probably, on a genetic basis).