Asbestos-related mesothelioma in Monfalcone, Italy

Variant Enrichment Analysis to Explore Pathways Disruption in a Necropsy Series of Asbestos-Exposed Shipyard Workers

The variant enrichment analysis (VEA), a recently developed bioinformatic workflow, has been shown to be a valuable tool for whole-exome sequencing data analysis, allowing finding differences between the number of genetic variants in a given pathway compared to a reference dataset. In a previous study, using VEA, we identified different pathway signatures associated with the development of pulmonary toxicities in mesothelioma patients treated with radical hemithoracic radiation therapy. Here, we used VEA to discover novel pathways altered in individuals exposed to asbestos who developed or not asbestos-related diseases (lung cancer or mesothelioma). A population-based autopsy study was designed in which asbestos exposure was evaluated and quantitated by investigating objective signs of exposure. We selected patients with similar exposure to asbestos. Formalin-fixed paraffin-embedded (FFPE) tissues were used as a source of DNA and whole-exome sequencing analysis was performed, running VEA to identify potentially disrupted pathways in individuals who developed thoracic cancers induced by asbestos exposure. By using VEA analysis, we confirmed the involvement of pathways considered as the main culprits for asbestos-induced carcinogenesis: oxidative stress and chromosome instability. Furthermore, we identified protective genetic assets preserving genome stability and susceptibility assets predisposing to a worst outcome.

Sailors and the Risk of Asbestos-Related Cancer

Sailors have long been known to experience high rates of injury, disease, and premature death. Many studies have shown asbestos-related diseases among shipyard workers, but few have examined the epidemiology of asbestos-related disease and death among asbestos-exposed sailors serving on ships at sea. Chrysotile and amphibole asbestos were used extensively in ship construction for insulation, joiner bulkhead systems, pipe coverings, boilers, machinery parts, bulkhead panels, and many other uses, and asbestos-containing ships are still in service. Sailors are at high risk of exposure to shipboard asbestos, because unlike shipyard workers and other occupationally exposed groups, sailors both work and live at their worksite, making asbestos standards and permissible exposure limits (PELs). based on an 8-h workday inadequate to protect their health elevated risks of mesothelioma and other asbestos-related cancers have been observed among sailors through epidemiologic studies. We review these studies here.

Pleural mesothelioma and lung cancer: the role of asbestos exposure and genetic variants in selected iron metabolism and inflammation genes

Two of the major cancerous diseases associated with asbestos exposure are malignant pleural mesothelioma (MPM) and lung cancer (LC). In addition to asbestos exposure, genetic factors have been suggested to be associated with asbestos-related carcinogenesis and lung genotoxicity. While genetic factors involved in the susceptibility to MPM were reported, to date the influence of individual genetic variations on asbestos-related lung cancer risk is still poorly understood. Since inflammation and disruption of iron (Fe) homeostasis are hallmarks of asbestos exposure affecting the pulmonary tissue, this study aimed at investigating the association between Fe-metabolism and inflammasome gene variants and susceptibility to develop LC or MPM, by comparing an asbestos-exposed population affected by LC with an "asbestos-resistant exposed population". A retrospective approach similar to our previous autopsy-based pilot study was employed in a novel cohort of autoptic samples, thus giving us the possibility to corroborate previous findings obtained on MPM by repeating the analysis in a novel cohort of autoptic samples. The protective role of HEPH coding SNP was further confirmed. In addition, the two non-coding SNPs, either in FTH1 or in TF, emerged to exert a similar protective role in a new cohort of LC exposed individuals from the same geographic area of MPM subjects. No association was found between NLRP1 and NLRP3 polymorphisms with susceptibility to develop MPM and LC. Further research into a specific MPM and LC "genetic signature" may be needed to broaden our knowledge of the genetic landscape attributed to result in MPM and LC.

Malignant Mesothelioma in Rome, Italy 1980-1995. A Retrospective Study of 79 Patients

Aim and background

To evaluate the characteristics of a case-series of 79 malignant mesothelioma patients collected from the main teaching hospital of Rome, Italy, and other local clinics of Latium Region and to assess the role of asbestos exposure, since previous studies on the occurrence of the disease in this area were lacking.

Methods

The study included cytohistologically diagnosed malignant mesothelioma (71 pleural, 7 peritoneal, and 1 testicular tunica vaginalis) detected or referred for consultation during the period 1980-1995. Information regarding occupational and/or nonoccupational exposures was derived from clinical records and interviews, when available.

Results

Patients were resident in Rome and other towns of Latium; a few were from other parts of central and southern Italy. Exposure to asbestos was assessed for 45.5% of patients, another 45.5% had unknown exposure, and for the remaining 9% such information was lacking. Occupational exposure occurred in 53% of men for whom information was available and nonoccupational exposure occurred in 20% of women. The study identified two clusters of cases from an asbestos-cement plant and a facility where asbestos was ubiquitous. Furthermore, most exposed subjects reported occupations in the construction industry, which is particularly active in the Latium Region; others were railroad workers, naval mechanics and navy personnel, bakers, explosive workers and car mechanics. A few patients reported indoor exposure to asbestos at home and/or in the workplace.

Conclusions

The study confirmed that mesothelioma risk is present in several job titles of the construction industry, and it is no longer confined to workers employed in the manufacture or application of asbestos products. The occurrence of malignant mesothelioma in patients with unexpected occupational and nonoccupational exposures indicates the need for further investigation on previously underestimated exposures.

A genetic variant of NLRP1 gene is associated with asbestos body burden in patients with malignant pleural mesothelioma

The presence of asbestos bodies (ABs) in lung parenchyma is considered a histopathologic hallmark of past exposure to asbestos fibers, of which there was a population of longer fibers. The mechanisms underlying AB formation are complex, involving inflammatory responses and iron (Fe) metabolism. Thus, the responsiveness to AB formation is variable, with some individuals appearing to be poor AB formers. The aim of this study was to disclose the possible role of genetic variants of genes encoding inflammasome and iron metabolism proteins in the ability to form ABs in a population of 81 individuals from North East Italy, who died after having developed malignant pleural mesothelioma (MPM). This study included 86 genetic variants distributed in 10 genes involved in Fe metabolism and 7 genetic variants in two genes encoding for inflammasome molecules. Genotypes/haplotypes were compared according to the number of lung ABs. Data showed that the NLRP1 rs12150220 missense variant (H155L) was significantly correlated with numbers of ABs in MPM patients. Specifically, a low number of ABs was detected in individuals carrying the NLRP1 rs12150220 A/T genotype. Our findings suggest that the NLRP1 inflammasome might contribute in the development of lung ABs. It is postulated that the NLRP1 missense variant may be considered as one of the possible host genetic factors contributing to individual variability in coating efficiency, which needs to be taken when assessing occupational exposure to asbestos.

Iron signature in asbestos-induced malignant pleural mesothelioma: A population-based autopsy study

Malignant pleural mesothelioma (MPM) is an aggressive cancer with poor prognosis. The development of MPM is frequently linked to inhalation of asbestos fibers. A genetic component of susceptibility to this disease is suggested by the observation that some individuals develop MPM following lower doses of asbestos exposure, whereas others exposed to higher quantities do not seem to be affected. This hypothesis is supported also by frequent reports of MPM familial clustering. Despite the widely recognized role of iron (Fe) in cellular asbestos-induced pulmonary toxicity, the role of the related gene polymorphisms in the etiology of MPM has apparently not been evaluated. Eighty-six single-nucleotide polymorphisms (SNPs) of 10 Fe-metabolism genes were examined by exploiting formalin-fixed paraffin-embedded postmortem samples from 77 patients who died due to MPM (designated AEM) and compared with 48 who were exposed to asbestos but from died in old age of cause other than asbestos (designated AENM). All subjects showed objective signs of asbestos exposure. Three SNPs, localized in the ferritin heavy polypeptide, transferrin, and hephaestin genes, whose frequencies were distributed differently in AEM and AENM populations, were identified. For ferritin and transferrin the C/C and the G/G genotypes, respectively, representing intronic polymorphisms, were significantly associated with protection against MPM and need to be considered as possible genetic markers of protection. Similarly, the C/C hephaestin SNP, a missense variation of this multicopper ferroxidase encoding gene, may be related, also functionally, with protection against MPM. In conclusion, it is proposed that three Fe metabolism-associated genes, significantly associated with protection against development of MPM, may serve as protective markers for this aggressive tumor.

Peritoneal mesothelioma in Italy: Trends and geography of mortality and incidence

INTRODUCTION

Peritoneal mesothelioma, a very rare and lethal malignancy, has not been investigated as extensively as pleural mesothelioma, although the role of asbestos exposure in its occurrence is well-known. Data from Italy are relevant, as it was the largest European asbestos producer, and asbestos was widely used in many economic activities.

METHODS

A population-based mortality and incidence analysis was performed in Italy. Data sources were the National Multiple-causes-of-death Database (1995-2010) and the Italian Mesothelioma Register (1993-2008).

RESULTS

We found an increasing trend of age standardized mortality rates in men, but no clear trend in women; moreover, we showed significant risks of death in several northern regions, formerly heavy asbestos users; finally, mortality/incidence ratios similar for both genders (about 0.8) were estimated.

CONCLUSIONS

The study, based on national data, showed a higher risk of mortality from and incidence of peritoneal mesothelioma in areas with formerly heavy exposure to asbestos.

The latency period of mesothelioma among a cohort of British asbestos workers (1978-2005)

Background:

The Great Britain (GB) Asbestos Survey is a prospective cohort of asbestos workers in GB. The objective of this study was to investigate determinants of mesothelioma latency, paying particular attention to indicators of intensity of asbestos exposure such as occupation, sex, and presence of asbestosis.

Methods:

The analysis included members of the cohort who died with mesothelioma between 1978 and 2005. The primary outcome was the latency period defined as the time from first occupational exposure to asbestos to death with mesothelioma. Generalised gamma accelerated failure-time models were used to estimate time ratios (TRs).

Results:

After excluding missing data, there were 614 workers who died with mesothelioma between 1978 and 2005. Total follow-up time was 9280 person-years, with a median latency of 22.8 years (95% confidence interval (CI) 16.0–27.2 years). In the fully adjusted model, latency was around 29% longer for females compared with males (TR=1.29, 95% CI=1.18–1.42), and 5% shorter for those who died with asbestosis compared with those who did not (TR=0.95, 95% CI=0.91–0.99). There was no evidence of an association between latency and occupation.

Conclusion:

This study did not find sufficient evidence that greater intensity asbestos exposures would lead to shorter mesothelioma latencies.

Mesothelioma among shipyard workers in Monfalcone, Italy

Background:

The high mesothelioma incidence in Monfalcone, Italy, is mainly attributable to shipbuilding activity. Mesothelioma risk among shipyard workers in Monfalcone is poorly defined.

Materials and Methods:

Workers hired at the Monfalcone shipyards in the period 1950-1959 were identified by surveying shipyard roll. The list of the workers was coupled with the archive data of Monfalcone and Trieste Hospitals. Mesotheliomas diagnosed in the above people were reexamined.

Results:

Of 1,403 workers hired in 1950-1959, 35 were diagnosed with mesothelioma (34 pleural, one peritoneal) between 1978 and 2012. Latency periods exceeded 40 years in 31 cases. The highest percentage of mesotheliomas was observed among people aged 14–19 years at hiring time (3.4%). Four mesothelioma patients had a blood relative with the same tumor.

Conclusions:

The present findings show high mesothelioma percentage among shipyard workers hired at young ages. The effects of asbestos exposure begun in 1950-1959 cannot be considered as exhausted.

Pleural mesothelioma mortality and asbestos exposure mapping in Italy

BACKGROUND

An epidemic of asbestos-related diseases is ongoing worldwide. Mortality from malignant pleural neoplasms in Italy was analyzed, to estimate the health impact of asbestos at national and local level.

METHODS

Mortality from ICD-9 code 163 was considered, in the time-window 1995-2002, using National Bureau of Statistics data. National and regional standardized rates and municipal Standardized Mortality Ratios (SMR) were calculated. Municipal clusters were identified by applying Spatial Scan Statistics procedure. Relative risks (RR) express the ratio of risk within the cluster to the risk outside the cluster.

RESULTS

The national standardized annual mortality rate was 1.9 per 100,000. Significant clusters corresponded to asbestos-cement industries (Casale Monferrato: RR = 11.63), shipyards (Monfalcone, RR = 7.43), oil refineries (Falconara, RR = 2.52), petrochemical industries (Priolo, RR = 3.81).

CONCLUSIONS

The present study confirms malignant pleural neoplasms mortality as a suitable indicator of asbestos exposure at geographic level. In addition to asbestos-cement industries and shipyards, other industrial settings are associated with pleural neoplasm mortality.

Malignant mesothelioma: facts, myths, and hypotheses

Malignant mesothelioma (MM) is a neoplasm arising from mesothelial cells lining the pleural, peritoneal, and pericardial cavities. Over 20 million people in the US are at risk of developing MM due to asbestos exposure. MM mortality rates are estimated to increase by 5-10% per year in most industrialized countries until about 2020. The incidence of MM in men has continued to rise during the past 50 years, while the incidence in women appears largely unchanged. It is estimated that about 50-80% of pleural MM in men and 20-30% in women developed in individuals whose history indicates asbestos exposure(s) above that expected from most background settings. While rare for women, about 30% of peritoneal mesothelioma in men has been associated with exposure to asbestos. Erionite is a potent carcinogenic mineral fiber capable of causing both pleural and peritoneal MM. Since erionite is considerably less widespread than asbestos, the number of MM cases associated with erionite exposure is smaller. Asbestos induces DNA alterations mostly by inducing mesothelial cells and reactive macrophages to secrete mutagenic oxygen and nitrogen species. In addition, asbestos carcinogenesis is linked to the chronic inflammatory process caused by the deposition of a sufficient number of asbestos fibers and the consequent release of pro-inflammatory molecules, especially HMGB-1, the master switch that starts the inflammatory process, and TNF-alpha by macrophages and mesothelial cells. Genetic predisposition, radiation exposure and viral infection are co-factors that can alone or together with asbestos and erionite cause MM. J. Cell. Physiol. 227: 44-58, 2012. © 2011 Wiley Periodicals, Inc.

Shipbuilding and mesothelioma in Monfalcone, Italy

The Monfalcone area, northeastern Italy, a small industrial district with large shipyards, shows a high incidence of asbestos-related mesothelioma. In order to reconstruct some features of the Monfalcone shipbuilding activity during World War II and its health effects, the shipyard roll were examined, and people hired in 1942 were identified. The list of 2,776 persons hired in 1942 was coupled with the Pathological Anatomy Units archives of the Monfalcone and the Trieste Hospitals. Eighteen of the above persons had been diagnosed with pleural mesothelioma in the period 1981-2005. Eight patients had their first exposure in 1942, and the others had histories of previous exposures. Of 557 persons aged 14-15 years in 1942, six had a diagnosis of pleural mesothelioma. Necropsy findings were available in 14 cases. The burdens of lung asbestos bodies, isolated in 11 cases, showed wide variation (from 150 to 600,000 bodies per gram of dried tissue). While probably underestimated, the present data indicate a high incidence of mesothelioma among the shipyard workers of Monfalcone.

Synchrotron soft X-ray imaging and fluorescence microscopy reveal novel features of asbestos body morphology and composition in human lung tissues

Background

Occupational or environmental exposure to asbestos fibres is associated with pleural and parenchymal lung diseases. A histopathologic hallmark of exposure to asbestos is the presence in lung parenchyma of the so-called asbestos bodies. They are the final product of biomineralization processes resulting in deposition of endogenous iron and organic matter (mainly proteins) around the inhaled asbestos fibres. For shedding light on the formation mechanisms of asbestos bodies it is of fundamental importance to characterize at the same length scales not only their structural morphology and chemical composition but also to correlate them to the possible alterations in the local composition of the surrounding tissues. Here we report the first correlative morphological and chemical characterization of untreated paraffinated histological lung tissue samples with asbestos bodies by means of soft X-ray imaging and X-Ray Fluorescence (XRF) microscopy, which reveals new features in the elemental lateral distribution.

Results

The X-ray absorption and phase contrast images and the simultaneously monitored XRF maps of tissue samples have revealed the location, distribution and elemental composition of asbestos bodies and associated nanometric structures. The observed specific morphology and differences in the local Si, Fe, O and Mg content provide distinct fingerprints characteristic for the core asbestos fibre and the ferruginous body. The highest Si content is found in the asbestos fibre, while the shell and ferruginous bodies are characterized by strongly increased content of Mg, Fe and O compared to the adjacent tissue. The XRF and SEM-EDX analyses of the extracted asbestos bodies confirmed an enhanced Mg deposition in the organic asbestos coating.

Conclusions

The present report demonstrates the potential of the advanced synchrotron-based X-ray imaging and microspectroscopy techniques for studying the response of the lung tissue to the presence of asbestos fibres. The new results obtained by simultaneous structural and chemical analysis of tissue specimen have provided clear evidence that Mg, in addition to Fe, is also involved in the formation mechanisms of asbestos bodies. This is the first important step to further thorough investigations that will shed light on the physiopathological role of Mg in tissue response to the asbestos toxicity.

Malignant pleural mesothelioma in Italy

This study reviews a series of 811 malignant pleural mesothelioma cases, diagnosed at hospitals in Trieste and Monfalcone districts of north eastern Italy, a narrow coastal strip with a population of about three lakh, in the period 1968-2008. The diagnosis was based on histological examination in 801 cases, and cytological findings in 10. Necropsy was performed in 610 cases. Occupational histories were obtained directly from the patients or their relatives through personal or telephone interviews. Routine lung sections were examined for asbestos bodies in 500 cases. In 143 cases asbestos bodies were isolated and counted by chemical digestion of the lung tissue using the Smith-Naylor method. The series included 717 men and 94 women aged between 32 and 93 years (mean 69.2 years). Detailed occupational data was obtained for 732 cases.The majority of patients had marine jobs - shipbuilding (449 cases), maritime trades (56 cases), and port activities (39 cases). The nature of work of other patients included a variety of occupations, with non-shipbuilding industries being the most common. Thirty-four women cleaned the work clothes of family members occupationally exposed and hence had a history of asbestos exposure at home. Most of the patients had their first exposure to asbestos before 1960. The latency period ranged between 13 and 73 years (mean 48.2). Latency period among insulators and dock workers were shorter than other categories. Asbestos bodies were detected on routine lung sections in 343 cases (68.6%). Lung asbestos body burdens after isolation ranged between two to 10 millions bodies per gram of dried tissue. Despite some limitations in the use of asbestos in this area since the 1970s, the incidence of tumor remained high during the last years.

Magnitude of asbestos-related lung cancer mortality in Italy

An ecological study, based on a data set containing all lung and pleural cancer deaths in each Italian municipality in the period 1980–2001, was performed. The pleural to lung cancer ratio was estimated to be 1 : 1 and 3% (around 700) of all male lung cancer deaths were found to be asbestos-related.

Asbestos exposure in lung carcinoma: a necropsy-based study of 414 cases

BACKGROUND

The prerequisites necessary for attributing lung carcinoma to asbestos, represent a controversial issue.

METHODS

Three parameters (occupational history, pleural plaques, and lung asbestos bodies) were investigated in 414 consecutive cases of lung carcinoma, examined at necropsy at the Hospital of Monfalcone, Italy. Occupational data were obtained from the patients' relatives by personal or telephone interviews. Pleural plaques were classified into three classes (small, moderate, large). Routine lung sections were examined for asbestos bodies in all cases; isolation and counting were performed in 408 cases.

RESULTS

The series included 353 men, and 61 women, aged between 38 and 97 years. The male patients had worked in industries in 74% of cases (60% in shipbuilding). Men showed pleural plaques in 82% of cases (moderate or large plaques in 58.7%). Asbestos bodies were observed in routine lung sections in 34.8%, and in 31% exceeded the value of 5,000 bodies per gram of dried tissue. Among women the principal features were: history or domestic exposure to asbestos in 36% of the cases, prevalence of pleural plaques 34% (moderate or large plaques 15%), asbestos bodies in routine lung sections in 3.3% and there was no case with an asbestos body burden over 5,000/g. The fraction of asbestos-related carcinomas among male patients varied between 24.7 and 61%, depending on the criteria used for attribution.

CONCLUSIONS

Different criteria indicated about 60% of the present lung carcinomas among men as plausibly attributable to asbestos.

Health and work among women in Italy: an overview of the epidemiological literature

The objective of this paper is to give an overview of the epidemiological studies completed in Italy during the past 25 years, about the role of occupational exposures on the development of adverse health effects on women. The implications for research developments are also discussed. The epidemiological investigations of selected categories of work-related health effects published in Italy in the years 1970-1995 were identified from the medical literature databases. The total number of studies is 142, including cohort mortality studies (n = 12), case-control studies of different neoplasms (n = 14), investigations of adverse reproductive effects (n = 8) and studies of occupational diseases different from the above (n = 94). In most investigations, women workers were not the main study objective and hence the number of females under study was small. The conclusions is that in Italy, given the dearth of studies of female workers and the preponderance of women in many economic sectors, i.e. the textile and shoe industry, health care, personal services and schools, there is a need to identify women workers in the above industries and occupations as priorities for epidemiological research and surveillance.

Pleural mesothelioma and household asbestos exposure

This article discusses the development of asbestos-induced malignant mesotheliomas after non-occupational environmental exposure to asbestos through contact with occupationally exposed household members. In our policlinic, we have seen six fatal pleural mesothelioma cases (five wives and one son of asbestos-industry workers) with no history of occupational asbestos exposure. In five women, a causal relation was established between the fatal disease and inhalation of asbestos fibers while cleaning the contaminated work-clothes and shoes of their husbands at home. The son had also been exposed to asbestos throughout his childhood during daily visits with his father at the workplace.

Diagnosis of malignant tumor: comparison between clinical and autopsy diagnoses

A review was made of the results of 1,036 consecutive autopsies (average patient age, 75 years; 617 male and 419 female patients; autopsy rate, 40.2%) done at the Hospital of Monfalcone from January 1986 through December 1991. In 457 autopsies (44%) one or more malignant neoplasms were found (single tumor in 382, dual tumor in 69, and triple tumor in six) for a total of 538 tumors. In the corresponding death certificates the clinical diagnosis of malignancy was found in 302 autopsies for a total of 310 tumors (single in 294 and dual in eight). The number of clinically unrecognized malignancies was 228 (42%) and the number of patients with undiagnosed tumors was 155 (34%). The neoplasms were subdivided into four stages according to their extension at autopsy: stage 0 (85 tumors), microscopic neoplasm; stage I (146 tumors), neoplasm localized at the site of origin; stage II (43 tumors), local advanced neoplasm; and stage III (264 tumors), neoplasm with metastases. The rate of correct clinical diagnoses increased according to the level of stage; (stage 0, 1%; stage I, 40%; stage II, 58%; and stage III, 66%). The greatest numbers of tumors found at autopsy were located in the gastroenteric apparatus (170), the respiratory apparatus (149), and the urogenital apparatus (130). The number of clinically undiagnosed neoplasms was high with respect to the urogenital apparatus (77% overall and 51% excluding stage 0) and the gastroenteric apparatus (41% and 38% excluding stage 0); in contrast, the number was low for the respiratory apparatus (17%). The rate of correct diagnoses was higher in patients younger than 65 years (65%) than in those older than 65 (54%), but the difference was not significant. The duration of hospitalization in the 12 months before death was statistically higher (P < .001) in patients with a correct diagnosis (36 days) than in undiagnosed patients (14 days). Even taking into account the biases that affect selection of patients for autopsy, the notable discrepancy found between clinical and autopsy diagnoses underlines the fact that autopsy, despite improvements in diagnostic techniques, maintains its fundamental importance in assessing the reliability of clinical diagnoses and furthermore shows the underestimation of the incidence of tumors in epidemiological studies based solely on death certificates.