Considerations about the epidemiologic surveillance system on mesothelioma in Tuscany (Italy) after 25 years of activity

OBJECTIVE AND DESIGN: To present problems and opportunities related to the operating procedures developed by the Tuscan epidemiological surveillance system on mesothelioma during its 25 years of activity. SETTING AND PARTICIPANTS: All 1,224 mesotheliomas, registered up to 31.12. 2011, diagnosed in Tuscan residents during 1988-2009 by the Tuscan Operating Centre of the Italian registry, have been considered. MAIN OUTCOME MEASURES: In order to evaluate accuracy and completeness of cases, the following indicators by period are used for pleural mesotheliomas diagnosed during 1988-2009: the distribution of the sources of cases' diagnosis and report to the regional registry, the latency time between diagnosis and report, the age and sex specific rates, the ratio between standardized mortality and incidence rates. The distribution of type of interview and exposure classification by period for all cases were used to evaluate the collected and classified exposure information. RESULTS: Histology with immunohistochemistry became the chosen method (97.4% of histological cases in 2005- 2009). Since the second half of the Nineties, other Italian regional Operating Centres and, more recently, the Workers Compensation Authority (INAIL) became new important sources of case report. Nowadays, the mortality/incidence ratio is closer to 1. The latency time between diagnosis and case report have been reducing with a consequent increase in direct interviews to cases (from 20.3% in 1988-1993 to 71.4% in 2005-2009) and in exposure information and classification quality. CONCLUSION: The regional network with the effective cooperation of the Local Health Authorities produced relevant improvements in the quality of the epidemiological surveillance system. It is hoped that the new revision of the national Guidelines will succeed in taking into consideration all the improvements made by the surveillance system in order to get over the difficulties observed in defining and classifying cases and their asbestos exposure.