A. Gilg Soit Ilg

The French National Mesothelioma Surveillance Program

Objectives: The French National Mesothelioma Surveillance Program (NMSP) was established in 1998 by the National Institute for Health Surveillance (InVS). Its objectives are to estimate the trends in mesothelioma incidence and the proportion attributable to occupational asbestos exposure, to help improve its pathology diagnosis, to assess its compensation as an occupational disease, and to contribute to research. Methods: The NMSP records incident pleural tumours in 21 French districts that cover a population of approximately 16 million people (a quarter of the French population). A standardised procedure of pathological and clinical diagnosis ascertainment is used. Lifetime exposure to asbestos and to other factors (man made mineral fibres, ionising radiation, SV40 virus) is reconstructed, and a case-control study was also conducted. The proportion of mesothelioma compensated as an occupational disease was assessed. Results: Depending on the hypothesis, the estimated number of incident cases in 1998 ranged from 660 to 761 (women: 127 to 146; men: 533 to 615). Among men, the industries with the highest risks of mesothelioma are construction and ship repair, asbestos industry, and manufacture of metal construction materials; the occupations at highest risk are plumbers, pipe-fitters, and sheet-metal workers. The attributable risk fraction for occupational asbestos exposure in men was 83.2% (95% CI 76.8 to 89.6). The initial pathologist’s diagnosis was confirmed in 67% of cases, ruled out in 13%, and left uncertain in the others; for half of the latter, the clinical findings supported a mesothelioma diagnosis. In all, 62% applied for designation of an occupational disease, and 91% of these were receiving workers’ compensation. Conclusions: The NMSP is a large scale epidemiological surveillance system with several original aspects, providing important information to improve the knowledge of malignant pleural mesothelioma, such as monitoring the evolution of its incidence, of high risk occupations and economic sectors, and improving pathology techniques.

Occupational and non-occupational attributable risk of asbestos exposure for malignant pleural mesothelioma

Objectives To estimate the proportion of pleural mesothelioma cases that can be attributed to asbestos exposure in France including non-occupational exposure. Methods A population-based case-control study including 437 incident cases and 874 controls was conducted from 1998 to 2002. Occupational and non-occupational asbestos exposure was assessed retrospectively by two expert hygienists. ORs of pleural mesothelioma for asbestos-exposed subjects compared to non-exposed subjects, and population-attributable risk (ARp) of asbestos exposure were estimated using a conditional logistic regression. Results A clear dose-response relationship was observed between occupational asbestos exposure and pleural mesothelioma (OR=4.0 (99% CI 1.9 to 8.3) for men exposed at less than 0.1 f/mL-year vs 67.0 (99% CI 25.6 to 175.1) for men exposed at more than 10 f/mL-year). The occupational asbestos ARp was 83.1% (99% CI 74.5% to 91.7%) for men and 41.7% (99% CI 25.3% to 58.0%) for women. A higher risk of pleural mesothelioma was observed in subjects non-occupationally exposed to asbestos compared to those never exposed. The non-occupational asbestos ARp for these subjects was 20.0% (99% CI −33.5% to 73.5%) in men and 38.7% (99% CI 8.4% to 69.0%) in women. When considering all kinds of asbestos exposure, ARp was 87.3% (99% CI 78.9% to 95.7%) for men and 64.8% (99% CI 45.4% to 84.3%) for women. Conclusions Our study suggests that the overall ARp in women is largely driven by non-occupational asbestos exposure arguing for the strong impact of such exposure in pleural mesothelioma occurrence. Considering the difficulty in assessing domestic or environmental asbestos exposure, this could explain the observed difference in ARp between men and women.

Evolution of pleural cancers and malignant pleural mesothelioma incidence in France between 1980 and 2005.

The evolution of pleural cancers and malignant pleural mesothelioma incidence in France between 1980 and 2005 was analysed using data derived from the French network of cancer registries (FRANCIM) and the French National Mesothelioma Surveillance Program (PNSM). Mesothelioma proportions in pleural cancers were calculated by diagnosis year in the 1980–2000 period. Our results suggest that the incidences of pleural cancer and mesothelioma levelled off in French men since 2000 and continued to increase in French women. A decrease of the annual pleural cancer incidence average in men was noticed (−3.4% of annual rate of change) between 2000 and 2005. The proportion of pleural cancers that were mesothelioma was unchanged between 1980 and 2003 with an average of 86%. The age standardised incidence rate of pleural mesothelioma remained relatively stable between 1998 and 2005 with a slight falling trend. For women, the age standardised incidence rate of pleural cancers and mesothelioma increased during the period 1998–2005. Additionally, the proportion of pleural cancers that were mesothelioma increased during the same period of time. Finally, the increased trend observed in the incidence of pleural mesothelioma and cancers in women is credibly due to their under diagnosis in the 1980–1997 period. The comparison between the French incidence and the American and British ones shows that the decreasing trend in incidence of mesothelioma and pleural cancers in French men since 2000 is potentially associated with a lower amphibole consumption and by the implementation of safety regulations at work from 1977.

Mésothéliome : les dispositifs en place en France « le réseau mésothéliome » 1998–2013

Mesothelioma is a rare disease less than 0.3% of cancers in France, very aggressive and resistant to the majority of conventional therapies. Asbestos exposure is nearly the only recognized cause of mesothelioma in men observed in 80% of case. In 1990, the projections based on mortality predicted a raise of incidence in mesothelioma for the next three decades. Nowadays, the diagnosis of this cancer is based on pathology, but the histological presentation frequently heterogeneous, is responsible for numerous pitfalls and major problems of early detection toward effective therapy. Facing such a diagnostic, epidemiological and medico-legal context, a national and international multidisciplinary network has been progressively set up in order to answer to epidemiological survey, translational or academic research questions. Moreover, in response to the action of the French Cancer Program (action 23.1) a network of pathologists was organized for expert pathological second opinion using a standardized procedure of certification for mesothelioma diagnosis. We describe the network organization and show the results during this last 15years period of time from 1998-2013. These results show the major impact on patients management, and confirm the interest of this second opinion to provide accuracy of epidemiological data, quality of medico-legal acknowledgement and accuracy of clinical diagnostic for the benefit of patients. We also show the impact of these collaborative efforts for creating a high quality clinicobiological, epidemiological and therapeutic data collection for improvement of the knowledge of this dramatic disease.

Confrontation des données du Programme national de surveillance du mésothéliome (PNSM) et du Programme de médicalisation du système d’information (PMSI): Comparison of the French DRG based information system (PMSI) with the National Mesothelioma Surveillance Program database

BACKGROUND One of the main purposes of the French National Mesothelioma Surveillance Program is to estimate and follow the national incidence of pleural mesothelioma. We wanted to study the contribution of the French hospital national database as a valid source of mesothelioma incident cases. METHODS From the 1998 and 1999 hospital national database, medical records with a diagnosis code of mesothelioma or pleural cancer where selected among patients who resided in one of the 17 administrative divisions covered by the National Mesothelioma Surveillance Program in 1998. From these records, 506 patients in 1998 and 474 patients in 1999 where identified and matched with the National Mesothelioma Surveillance Program cases over the same period using indirect criteria of identification (sex, age, place of residence). Medical records of cases unknown by the National Mesothelioma Surveillance Program where consulted in one of the administrative divisions. RESULTS Only two-thirds of the registered cases of the National Mesothelioma Surveillance Program could be matched with a patient identified in the hospital national database with a diagnosis of mesothelioma registered during the same year. Consultation of the medical records showed that 1) certified cases registered in the National Mesothelioma Surveillance Program where often (83%) found in the hospital national database with a code of mesothelioma but 10 to 15% of the patients with a code of mesothelioma in the national hospital databases had a different diagnosis according to their medical records; 2) 65% of the patients with a code of mesothelioma in the national hospital databases that where unknown from the National Mesothelioma Surveillance Program in 1998 and 55% in 1999 where prevalent cases; 3) 3 suspected cases had not been reported to the National Mesothelioma Surveillance Program. CONCLUSION Because of lack of diagnosis certification, mistakes in encoding diagnosis and the fact that incident and prevalent cases cannot be distinguished in the hospital national database make it impossible to estimate the mesothelioma incidence solely from this source of data. However, the hospital claim databases constitute a complementary source of information for the active search of incident cases performed by the National Mesothelioma Surveillance Program.