Prevention and screening

ABSTRACT Background Patients with pleural mesothelioma and lung cancer associated with asbestos exposure has been recently increasing in Japan. The aim of this study was to prospectively evaluate the actual situation of asbestos exposure and the prevalence of asbestos-related diseases among Japanese general population. Materials and methods From 2006 to 2008, 9810 subjects (mean age, 57 years; 54% male and 50% smokers) underwent low-dose CT (LDCT) in 26 institutions in Japan. Then, 6286 (64.1%) subjects underwent subsequent screening after 2 years of interval. Clinical information such as history of asbestos exposure for all life was reviewed. Images were interpreted independently by 15 experts. Results Self-reported history of occupational exposure was present in 2805 (28.5%) subjects, whereas self-reported history of residential exposure was present in 1193 (12.2%) subjects although asbestos factory actually existed in 2870 (29.3%) subjects. Pleural plaque, pleural thickening, and pulmonary nodule were identified in 264 (2.7%), 245 (2.5%), and 1003 (10.2%) subjects on LDCT. However, self-reported history of asbestos exposure was not confirmed in 77 (29.2%) of 264 subjects with pleural plaque although asbestos factory actually existed in 65 (84.4%) of such 77 subjects. Pleural plaque on LDCT was significantly correlated with male (odds ratio OR, 2.32), age over 60 years (OR, 1.75), smoking (OR, 1.60), self-reported history of asbestos exposure (OR, 3.92), residential period in asbestos factory area (OR every 10 years, 1.13), and asbestos-related work period (7 work identified, OR every 10 years, 1.300-3–3.21). Moreover, lung cancer was identified in 29 (0.3%) subjects, resulting in significant correlation with age over 60 years (OR, 2.67) and pleural plaque (OR, 4.17). After repeated LDCT screening, among 6286 subjects consisting of 165 and 6121 subjects with and without pleural plaque on LDCT at baseline screening, respectively, 5 (3.0%) of 165 and 7 (0.1%) of 6121 subjects showed marked progression and new onset of pleural plaque, respectively. Again, lung cancer was identified in 8 (0.1%) subjects. Conclusion Our results indicate the potential risk of asbestos exposure among Japanese general population and the importance of public relations and enlightenment for especially residential asbestos exposure. Disclosure All authors have declared no conflicts of interest.