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Objectives: The purposes of this study are to describe the epidemiology of pericardial and tunica vaginalis testis mesothelioma and assess the role of asbestos exposure for these rare diseases. Methods: Based on incident pericardial and tunica vaginalis testis mesothelioma cases collected from the Italian national mesothelioma registry (ReNaM) in the period 1993–2015, incidence rates, survival median period and prognostic factors have been evaluated. A case–control study has been performed to analyze the association with asbestos exposure (occupational and non-occupational) for these diseases. Results: Between 1993 and 2015, 58 pericardial (20 women and 38 men) and 80 tunica vaginalis testis mesothelioma cases have been registered with a mean annual standardized (world standard population as reference) incidence rates of 0.049 (per million) in men and 0.023 in women for the pericardial site, and 0.095 for tunica vaginalis testis mesothelioma. Occupational exposure to asbestos was significantly associated with the risk of the diseases [odds ratio (OR) 3.68, 95% confidence interval (CI) 1.85–7.31 and OR 3.42, 95% CI 1.93–6.04 in pericardial and tunica vaginalis testis mesothelioma, respectively]. The median survival was 2.5 months for pericardial and 33.0 months for tunica vaginalis testis mesotheliomas. Age was the main predictive factor for survival for both anatomical sites. Conclusions: For the first time in an analytical study, asbestos exposure was associated with pericardial and tunica vaginalis testis mesothelioma risk, supporting the causal role of asbestos for all anatomical sites. The extreme rarity of the diseases, the poor survival and the prognostic role of age have been confirmed based on population and nationwide mesothelioma registry data.

Mezei et al's letter (1) is an opportunity to provide more details about our study on pericardial and tunica vaginalis testis (TVT) mesothelioma (2), which is based on the Italian national mesothelioma registry (ReNaM): a surveillance system on mesothelioma, with individual asbestos exposure assessment. Incidence of pericardial mesothelioma has been estimated around 0.5 and 0.2 cases per 10 million person-years in men and women, respectively, and around 1 case for TVT mesothelioma. ReNaM collected 138 cases thanks to its long period of observation (1993-2015) and national coverage. Conducting a population-based case-control study with incidence-density sampling of controls across Italy and over a 23 year time-span should have been planned in 1993 and would have been beyond feasibility and ReNaM scope. We rather exploited two existing series of controls (3). The resulting incomplete time- and spatial matching of cases and controls is a limitation of our study and has been acknowledged in our article. The analysis of case-control studies can nevertheless be accomplished in logistic models accounting for the variables of interest, in both individually and frequency matched studies (4). Furthermore, analyses restricted to (i) regions with enrolled controls, (ii) cases with definite diagnosis, (iii) incidence period 2000-2015, and (iv) subjects born before 1950 have been provided in the manuscript, confirming the strength of the association with asbestos exposure (supplemental material tables S4-7). Following Mezei et al's suggestion, we performed further sensitivity analyses by restriction to regions with controls and fitting conditional regression models using risk-sets made of combinations of age and year of birth categories (5-year classes for both). We confirmed positive associations with occupational exposure to asbestos of pericardial mesothelioma, with odds ratios (OR) (adjusted for region) of 9.16 among women [95% confidence interval (CI) 0.56-150] and 5.63 (95% CI 1.02-31.0) among men; for TVT mesothelioma the OR was 7.70 (95% CI 2.89-20.5). Using risk sets of age categories and introducing year of birth (5-year categories) as a covariate (dummy variables) the OR were similar: OR (adjusted for region) of 9.17 among women (95% CI 0.56-150) and 5.76 (95% CI 1.07-31.0) among men; for TVT the OR was 9.86 (95% CI 3.46-28.1). Possible bias from incomplete geographical overlap between cases and controls has been addressed in the paper (table S4) and above. In spatially restricted analyses, OR were larger than in those including cases from the whole country, indicating that bias was towards the null. Mezei et al further noted that "the regional distribution of controls is different from that of person-time observed". This objection is not relevant because the above analyses were adjusted by region. Our controls were provided by a population-based study on pleural mesothelioma (called MISEM) and a hospital-based study on cholangiocarcinoma (called CARA). In MISEM, the response rate was 48.4%, a low but not unexpected rate as participation among population controls is usually lower and has been declining over time (5). It is important to underline that ReNaM applied the same questionnaire that was used for interviews and carried out the same exposure assessment as both MISEM and CARA. As repeatedly stated in ReNaM papers (6-7), each regional operating center assesses asbestos exposure based on the individual questionnaire, other available information, and knowledge of local industries. Occupational exposure to asbestos is classified as definite, probable or possible. Occupational exposure is (i) definite when the subject`s work was reported or otherwise known to have involved the use of asbestos or asbestos-containing materials (MCA); (ii) probable when subjects worked in factories where asbestos or MCA were used, but their personal exposure could not be documented; and (iii) possible when they were employed in industrial activities known to entail the use of asbestos or MCA. Hence, the definite and probable categories are closer to one another and were combined in our analyses. In any case, restricting analyses to subjects with definite occupational exposure and using each set of controls separately, as suggested by Mezei et al, yielded elevated OR for TVT and pericardial mesothelioma among men using both the above described modelling strategies; the OR could not be calculated for women. There were 70 (25 pericardial and 45 TVT) occupationally exposed mesothelioma cases. In population-based studies, analyses by occupation are limited by the low prevalence of most specific jobs. As briefly reported in our paper, for purely descriptive purposes, the industrial activity of exposure (cases may have multiple exposures), were construction (22 exposures, 7 and 15 for pericardial and TVT mesotheliomas, respectively), steel mills and other metal working industries (4 and 11), textile industries (2 and 3), and agriculture (2 and 5); other sectors had lower exposure frequencies. The absence of industries like asbestos-cement production, shipbuilding and railway carriages production/repair should not be surprising and had already been observed (7). In the Italian multicenter cohort study of asbestos workers (8), given the person-years of observation accrued by workers employed in these industries and gender- and site-specific crude incidence rates, approximately 0.1 case of pericardial and 0.2 of TVT mesothelioma would have been expected from 1970 to 2010. Even increasing ten-fold such figures to account for higher occupational risks among these workers would not change much. Asbestos exposure in agriculture has been repeatedly discussed in ReNaM reports (9: pages 70, 73, 128, 164 and 205). Exposure opportunities included the presence of asbestos in wine production, reuse of hessian bags previously containing asbestos, or construction and maintenance of rural buildings. Similarly, mesothelioma cases and agricultural workers exposed to asbestos have been noted in France (10). In conclusion, the additional analyses we performed according to Mezei et al's suggestions confirm the association between asbestos exposure and pericardial and TVT mesothelioma, supporting the causal role of asbestos for all mesotheliomas. ReNaM`s continuing surveillance system with national coverage is a precious platform for launching analytical studies on pleural and extra pleural mesothelioma. References 1. Mezei G, Chang ET, Mowat FS, Moolgavkar SH. Comments on a recent case-control study of malignant mesothelioma of the pericardium and the tunica vaginalis testis Scand J Work Environ Health. 2021;47(1):85-86. https://doi.org/10.5271/3909 2. Marinaccio A, Consonni D, Mensi C, Mirabelli D, Migliore E, Magnani C et al.; ReNaM Working Group. Association between asbestos exposure and pericardial and tunica vaginalis testis malignant mesothelioma: a case-control study and epidemiological remarks. Scand J Work Environ Health. 2020;46(6):609-617. https://doi.org/10.5271/sjweh.3895. 3. Greenland S. Control-initiated case-control studies. Int J Epidemiol 1985 Mar;14(1):130-4. https://doi.org/10.1093/ije/14.1.130. 4. Pearce N. Analysis of matched case-control studies. BMJ 2016 Feb;352:i969. https://doi.org/10.1136/bmj.i969. 5. Bigert C, Gustavsson P, Straif K, Pesch B, Brüning T, Kendzia B et al. Lung cancer risk among cooks when accounting for tobacco smoking: a pooled analysis of case-control studies from Europe, Canada, New Zealand, and China. J Occup Environ Med 2015 Feb;57(2):202-9. https://doi.org/10.1097/JOM.0000000000000337. 6. Marinaccio A, Binazzi A, Marzio DD, Scarselli A, Verardo M, Mirabelli D et al.; ReNaM Working Group. Pleural malignant mesothelioma epidemic: incidence, modalities of asbestos exposure and occupations involved from the Italian National Register. Int J Cancer 2012 May;130(9):2146-54. https://doi.org/10.1002/ijc.26229. 7. Marinaccio A, Binazzi A, Di Marzio D, Scarselli A, Verardo M, Mirabelli D et al. Incidence of extrapleural malignant mesothelioma and asbestos exposure, from the Italian national register. Occup Environ Med 2010 Nov;67(11):760-5. https://doi.org/10.1136/oem.2009.051466. 8. Ferrante D, Chellini E, Merler E, Pavone V, Silvestri S, Miligi L et al.; the working group. Italian pool of asbestos workers cohorts: mortality trends of asbestos-related neoplasms after long time since first exposure. Occup Environ Med 2017 Dec;74(12):887-98. https://doi.org/10.1136/oemed-2016-104100. 9. ReNaM VI Report. Available from: https://www.inail.it/cs/internet/docs/alg-pubbl-registro-nazionale-mesoteliomi-6-rapporto.pdf. Italian 10. Marant Micallef C, Shield KD, Vignat J, Baldi I, Charbotel B, Fervers B et al. Cancers in France in 2015 attributable to occupational exposures. Int J Hyg Environ Health 2019 Jan;222(1):22-9. https://doi.org/10.1016/j.ijheh.2018.07.015.

Notwithstanding the ban in 1992, asbestos exposure for workers in the construction sector in Italy remains a concern. The purpose of this study is to describe the characteristics of malignant mesothelioma (MM) cases recorded by the Italian registry (ReNaM) among construction workers. Incident mesothelioma cases with a definite asbestos exposure have been analyzed. Characteristics of cases and territorial clusters of crude rates of MM in construction workers have been described, as well as the relation between asbestos use before the ban and the historical trend of workforce in the construction sector in Italy. ReNaM has collected 31,572 incident MM cases in the period from 1993 to 2018 and asbestos exposure has been assessed for 24,864 (78.2%) cases. An occupational exposure has been reported for 17,191 MM cases (69.1% of subjects with a definite asbestos exposure). Among them, 3574 had worked in the construction sector, with an increasing trend from 15.8% in the 1993–98 period to 23.9% in 2014–2018 and a ubiquitous territorial distribution. The large use of asbestos in construction sector before the ban makes probability of exposure for workers a real concern still today, particularly for those working in maintenance and removal of old buildings. There is a clear need to assess, inform, and prevent asbestos exposure in this sector.

Although the predominant occupation origin of mesothelioma is well known, determinant factors involved in filing compensation are scarcely investigated. A linkage between incident mesothelioma cases collected by Italian mesothelioma register (ReNaM) and compensation claims and assignment by Italian national insurance Institute (INAIL) has been conducted for cases diagnosed in the period 2010-2015 and occupational exposure to asbestos. Logistic regression models and decision tree models have been used to identify demographic, diagnostic and anamnestic factors significant for filing and receiving compensation. We have included in the analyses 5019 mesothelioma cases, and among them, 3321 (66.2 %) were found in INAIL archives as mesothelioma cases who fil claims for compensation. The modalities of asbestos exposure, sector of working activities and job type are crucial factors. Furthermore, gender, age at diagnosis, area of residence have been found to be significant predictors of probability to fil claims. Relative risks to fil claims were obtained for the above determinants and conditions to maximize the probability to obtain compensation identified. Our findings demonstrate that there is a need to enforce policies for improving awareness of the occupational origin for mesothelioma cases. Stakeholders, occupational health and safety institutions can play an important role for improving the sensitization regarding the rights of compensation benefits, ensuring the equity and the effectiveness of insurance, welfare and public health systems.

BACKGROUND: As a legacy of the large asbestos consumption until the definitive ban in 1992, Italy had to tackle a real epidemic of asbestos related diseases. The Italian National Registry of Malignant Mesotheliomas (ReNaM) is a permanent surveillance system of mesothelioma incidence, with a regional structure. Aims, assignments and territorial network of ReNaM are described, as well as data collection, recording and coding procedures. OBJECTIVES: To describe the Italian epidemiological surveillance system of mesothelioma incidence, to provide updated data about occurrence of malignant mesothelioma in Italy, and to discuss goals, attainments, and expectations of registering occupational cancer. DESIGN: Analysis of data by malignant mesothelioma incident cases surveillance system. SETTING AND PARTICIPANTS: Italy, network of regional sur-veillance system, all Italian regions. MAIN OUTCOME MEASURES: A Regional Operating Centre (COR) is currently established in all the Italian regions, actively searching incident malignant mesothelioma cases from health care institutions. Occupational history, lifestyle habits, and residential history are obtained using a standardized questionnaire, administered to the subject or to the next of kin by a trained interviewer. The extent of dataset, epide-miological parameters, and occupations involved are reported updated at 31.12.2016, and standardized incidence rates are calculated. RESULTS: At December 2016, ReNaM has collected 27,356 malignant mesothelioma cases, referring to the period of incidence between 1993 and 2015. The modalities of exposure to asbestos have been investigated for 21,387 (78%) and an occupational exposure has been defined for around 70% of defined cases (14,818). CONCLUSIONS: The Italian experience shows that epidemiological systematic surveillance of asbestos related diseases incidence has a key importance for assessing and monitoring the public health impact of occupational and/or environmental hazards, programming preventive interventions, including remediation plans and information campaigns, and supporting the efficiency of insurance and welfare system. Monitor-ing the incidence of malignant mesothelioma through a specialized cancer registry is essential to follow-up the health effects of changing modalities and extent of occupational exposures over years and of environmental contamination. Such consolidated surveillance system is recommended also for occupational cancers with low aetiological fraction.

IntroductionThe epidemiology of gender differences for mesothelioma incidence has been rarely discussed in national case lists. In Italy an epidemiological surveillance system (ReNaM) is working by the means of a national register.MethodsIncident malignant mesothelioma (MM) cases in the period 1993 to 2012 were retrieved from ReNaM. Gender ratio by age class, period of diagnosis, diagnostic certainty, morphology and modalities of asbestos exposure has been analysed using exact tests for proportion. Economic activity sectors, jobs and territorial distribution of mesothelioma cases in women have been described and discussed. To perform international comparative analyses, the gender ratio of mesothelioma deaths was calculated by country from the WHO database and the correlation with the mortality rates estimated.ResultsIn the period of study a case list of 21 463 MMs has been registered and the modalities of asbestos exposure have been investigated for 16 458 (76.7%) of them. The gender ratio (F/M) was 0.38 and 0.70 (0.14 and 0.30 for occupationally exposed subjects only) for pleural and peritoneal cases respectively. Occupational exposures for female MM cases occurred in the chemical and plastic industry, and mainly in the non-asbestos textile sector. Gender ratio proved to be inversely correlated with mortality rate among countries.ConclusionsThe consistent proportion of mesothelioma cases in women in Italy is mainly due to the relevant role of non-occupational asbestos exposures and the historical presence of the female workforce in several industrial settings. Enhancing the awareness of mesothelioma aetiology in women could support the effectiveness of welfare system and prevention policies.