Clinical study of asbestos‐related lung cancer in Japan with special reference to occupational history

Abstract

A total of 152 patients with asbestos-related lung cancer recognized by the criteria of Japanese compensation law for asbestosrelated diseases were examined and compared with 431 patients with non-asbestos-related lung cancer. Male comprised 96% of patients. Ages ranged from 50 to 91 years with a median of 72 years. Eighty-nine percent were smokers or ex-smokers. Almost all patients had occupational histories of asbestos exposure. The median duration of asbestos exposure was 31 years and the median latency period was 47 years. Thirty-four percent of patients exhibited asbestosis and 81% exhibited pleural plaques by radiography. Regarding asbestos particles in the lung for 73 operated or autopsied patients, 62% had more than 5,000 particles per gram. On the other hand, 100% of non-asbestos-related lung cancer patients had <5000 particles per gram with a median of 554 particles. The number of asbestos bodies in the lung, male gender, absence of symptoms, smoking index, and early stage of cancer were significantly much more than those of non-asbestos-related lung cancer. In this study, a diagnosis of asbestos-related lung cancer was made in 34% of patients by asbestosis, in 62% by presence of both pleural plaques and more than 10 years' occupational asbestos exposure, and in 4% by more than 5000 asbestos particles per gram of lung tissue. Occupational histories, duration of asbestos exposure, and pleural plaques are common categories for the recognition of asbestos-related lung cancer in Japan. (Cancer Sci 2010; 101: 1194-1198 T he disaster of asbestos exposure has been a serious social problem in Japan since 2005,(1) with neighborhood exposure to asbestos inducing mesothelioma in more than 100 patients in the Amagasaki area. Furthermore, the number of patients with mesothelioma and asbestos-related lung cancer ( Fig. 1) has recently increased. In this study, clinical features and occupational histories for asbestos-related lung cancer patients in Japan were investigated and compared with those of non-asbestos-related lung cancer patients. Materials and MethodsIn this study, the definition of asbestos-related lung cancer was primary lung cancer with the following: (i) asbestosis on chest radiography; (ii) pleural plaques with more than 10 years' occupational asbestos exposure; (iii) asbestos particles or fibers on the lung tissues with more than 10 years' occupational asbestos exposure; and (iv) more than 5000 asbestos particles per gram of dry lung tissue with occupational asbestos exposure. These criteria fulfill the Japanese compensation law of asbestos-related lung cancer.Retrospective study of asbestos-related lung cancer patients from 2000 to 2008 treated in 18 Rosai hospitals throughout Japan was performed. Gender, age, diagnostic motive, smoking history, histological type of lung cancer, clinical stage, therapeutic procedures and prognosis, occupational history, and radiological findings of asbestos-related changes were examined.Non-asbestos-related lung cancer patients treated in Okayama Rosai hospital fr...

Asbestos-Related Diffuse Pleural Thickening

“…Our results provide support for these previous findings and suggest that DPT can develop after moderate-to-high levels of exposure to asbestos, because the occupational category of the subjects in the current study included those of relatively high levels of asbestos exposure, such as asbestos product manufacturing and shipbuilding. The median latency period between asbestos exposure and DPT development in the present study was similar to that observed for malignant mesothelioma and lung cancer in our previous reports [15,16,17] and that for DPT in another report by Kee et al [18]. …”

Clinical study of asbestos‐related lung cancer diagnosed by asbestos medical examination

“…Regarding survival, we cannot state that the patients in this study with asbestos‐related lung cancer diagnosed by regular medical examination did not have an inferior prognosis to previously reported patients with non‐asbestos‐related lung cancer because of small sample size. It was reported that the prognosis of asbestos‐related lung cancer patients who underwent surgical treatment was better than that of patients for whom surgery was not indicated due to advanced clinical stage, which is compatible with our results.…”

Significant relationship between the extent of pleural plaques and pulmonary asbestos body concentration in lung cancer patients with occupational asbestos exposure

“…This criterion may not be applicable to some patients with chrysotile exposure. For the certification of workers' compensation, other administratively estimated criteria are applicable to such patients, including (i) asbestosis on CXR; (ii) pleural plaques with more than 10 years' occupational asbestos exposure; and (iii) asbestos bodies or fibers in the lung tissues with more than 10 years' occupational asbestos exposure [Kishimoto et al, 2010]. In addition, lung cancer patients who have PABCs between 1,000 and 5,000 AB/g dry lung have their lung tissue examined for their asbestos fibers by analytical transmission electron microscopy.…”

“…In the Japanese compensation and relief systems, PABC has been used as one of the eligible criteria for lung cancer caused by asbestos. People are deemed to have lung cancer caused by asbestos and are eligible for compensation and relief benefits if they have a PABC of !5,000 asbestos bodies per gram of dry lung tissue [Kishimoto et al, 2010]. Our research group has been measuring PABC to evaluate the cumulative exposure levels in lung cancer patients.…”