Forecast of Malignant Peritoneal Mesothelioma Mortality in Italy up to 2040

Asbestos burden in lungs of non-occupationally exposed women from Broni (Pavia, Italy): a postmortem SEM-EDS study

Background

In Italy the incidence of malignant mesothelioma (MM) among women is remarkably high, due to the several contexts in which women had been exposed to asbestos. However, very few studies in literature focus on the inorganic lung content in women. The aim of this retrospective, observational study is to investigate the asbestos lung burden, in terms of concentration, dimensions and type of asbestos, in 42 women who died from MM and had been non-occupationally exposed to asbestos during the activity of the asbestos-cement plant located in Broni (Pavia, Northern Italy) where mainly chrysotile, crocidolite and amosite were used.

Methods

Lung samples taken during forensic autopsies have been digested using sodium hypochlorite and filtered through a cellulose-ester membrane. The filter was examined using a scanning electron microscope and the chemical composition of the fibers was analyzed using an electron dispersive spectroscopy. The number of detected inorganic fibers, asbestos fibers and asbestos bodies (ABs) were normalized to 1 gram of dry tissue.

Results

In six samples no asbestos has been detected. Overall, the most represented kind of asbestos was amosite, followed by crocidolite, tremolite/actinolite asbestos and chrysotile. The concentration of all inorganic fibers was significantly higher in women with environmental and household exposures compared with those with only environmental exposure (P=0.025), as well as the concentration of asbestos fibers (P=0.019) and ABs (P=0.049). We found a significant correlation between the concentration of asbestos fibers and the duration of exposure (rho =0.413, P=0.008), as well as with the latency of MM (rho =0.427, P=0.005). The distance of the residential address from the factory and the time spent daily in contact with asbestos did not influence the lung asbestos burden.

Conclusions

These results suggest the relevance of the lung clearance of asbestos, regarding mainly chrysotile. As a consequence, although scanning electron microscopy -energy dispersive X-ray spectroscopy (SEM-EDS) is considered the most reliable tool for assessing previous exposure to asbestos, its results should be interpreted with caution, especially in a legal context. In addition, our data confirm the relevance of environmental and household exposure in determining asbestos concentration in lungs and highlight the importance of household exposure.

The Italian Experience in the Development of Mesothelioma Registries: A Pathway for Other Countries to Address the Negative Legacy of Asbestos

Asbestos (all forms, including chrysotile, crocidolite, amosite, tremolite, actinolite, and anthophyllite) is carcinogenic to humans and causally associated with mesothelioma and cancer of the lung, larynx, and ovary. It is one of the carcinogens most diffuse in the world, in workplaces, but also in the environment and is responsible for a very high global cancer burden. A large number of countries, mostly with high-income economies, has banned the use of asbestos which, however, is still widespread in low- and middle-income countries. It remains, thus, one of the most common occupational and environmental carcinogens worldwide. Italy issued an asbestos ban in 1992, following the dramatic observation of a large increase in mortality from mesothelioma and other asbestos-related diseases in exposed workers and also in subjects with non-occupational exposure. A mesothelioma registry was also organized and still monitors the occurrence of mesothelioma cases, conducting a case-by-case evaluation of asbestos exposure. In this report, we describe two Italian communities, Casale Monferrato and Broni, that faced an epidemic of mesothelioma resulting from the production of asbestos cement and the diffuse environmental exposure; we present the activity and results of the Italian mesothelioma registry (ReNaM), describe the risk-communication activities at the local and national level with a focus on international cooperation and also describe the interaction between mesothelioma registration and medical services specialized in mesothelioma diagnosis and treatment in an area at high risk of mesothelioma. Finally, we assess the potential application of the solutions and methods already developed in Italy in a city in Colombia with high mesothelioma incidence associated with the production of asbestos-cement materials and the presence of diffuse environmental asbestos pollution.

Epidemiology and outcome of peritoneal and pleural mesothelioma subtypes in Norway. A 20 year nation-wide study

BACKGROUND

Mesothelioma of the pleural or peritoneal cavities is one of the deadliest cancer types. The incidence of pleural subtypes has decreased over time due to decrease in asbestos exposure, and the current treatment landscape is changing due to introduction of novel therapies. In this study we have analysed contemporary epidemiological data of mesothelioma on a national level before the advent of immunotherapy.

MATERIAL AND METHODS

Complete national data on 1509 pleural and peritoneal malignant mesothelioma from the Cancer Registry of Norway from 2000 to 2019 are presented. Age standardised incidence and median survival were calculated.

RESULTS

The age-standardised incidence of pleural mesothelioma among males has decreased from 1.7 per 100 000 in 2000-2004 to 1.1 in 2015-2019, whereas the incidence for females has been stable, lower than 0.3 per 100 000 throughout the period. Incidence of peritoneal mesotheliomas remained low, below 0.08 per 100 000. The female to male ratio among pleural mesotheliomas was 1:7 with no differences among morphological subtypes, whereas this ratio was 1:1.2 in peritoneal mesotheliomas. Median age at diagnosis for pleural mesothelioma was 73 years and 76 years for females and males respectively in the last 5-year period, and 67 years for peritoneal mesotheliomas of both sexes. Median survival among pleural mesotheliomas has been stable, with significantly worse prognosis among sarcomatoid subtype (5.4 months) compared to epithelioid subtype (15.8 months). Peritoneal mesothelioma of the epithelioid subtype, representing 38% of cases, had a median survival of 43.3 months, contrasting the non-epithelioid subtype of 5.1 months.

DISCUSSION

Mesothelioma is still a significant disease with a dismal prognosis. Improvement in treatment is warranted.

Effect of Asbestos Consumption on Malignant Pleural Mesothelioma in Italy: Forecasts of Mortality up to 2040

Statistical models used to forecast malignant pleural mesothelioma (MPM) trends often do not take into account historical asbestos consumption, possibly resulting in less accurate predictions of the future MPM death toll. We used the distributed lag non-linear model (DLNM) approach to predict future MPM cases in Italy until 2040, based on past asbestos consumption figures. Analyses were conducted using data on male MPM deaths (1970-2014) and annual asbestos consumption using data on domestic production, importation, and exportation. According to our model, the peak of MPM deaths is expected to occur in 2021 (1122 expected cases), with a subsequent decrease in mortality (344 MPM deaths in 2039). The exposure-response curve shows that relative risk (RR) of MPM increased almost linearly for lower levels of exposure but flattened at higher levels. The lag-specific RR grew until 30 years since exposure and decreased thereafter, suggesting that the most relevant contributions to the risk come from exposures which occurred 20-40 years before death. Our results show that the Italian MPM epidemic is approaching its peak and underline that the association between temporal trends of MPM and time since exposure to asbestos is not monotonic, suggesting a lesser role of remote exposures in the development of MPM than previously assumed.

Integrating data from multidisciplinary Management of Malignant Pleural Mesothelioma: a cohort study

BACKGROUND

Malignant pleural mesothelioma (MPM) is a rare and aggressive malignancy that most commonly affects the pleural layers. MPM has a strong association with asbestos, mainly caused by exposure to its biopersistent fibers in at least 80% of cases. Individuals with a chronic exposure to asbestos might develop disease with a 20-40-year latency with few or no symptoms. Such has been the case in the Italian regions of Piedmont and Lombardy, where industrial production of materials laden with asbestos, mainly cements, has been responsible for the onset of a large epidemic. Since 2018, a multidisciplinary team at San Matteo hospital in Pavia has been collecting data on over 100 patients with MPM. The main goal of this project is to define and describe an integrated profile for each MPM case at diagnosis by using data mining and partition analysis.

METHODS

Here we bring together exhaustive epidemiologic, histologic and radiologic data of 88 MPM patients that came to our observation and draw correlations with predictive and prognostic significance.

RESULTS

The median overall survival (OS) was 15.6 months. Most patients presented with pleural effusion, irrespective of disease stage. Quite unexpectedly, no statistically significant association was demonstrated between OS and TNM disease stage at diagnosis. Although average OS is similar in male and female patients, partition analysis of data underlined a significant differential hierarchy of predictor categories based on patient gender. In females with no smoking history, full chemotherapeutic regimens are associated with better outcomes. Moreover, concerning second line treatments, vinorelbine emerged as the most advantageous choice for female patients, whereas in the male subgroup no statistically significant difference resulted between gemcitabine and vinorelbine.

CONCLUSION

A multidisciplinary approach to MPM is mandatory to define better therapeutic approaches, personalize the management and improve patient outcomes.