Clinical study on mesothelioma in Japan: Relevance to occupational asbestos exposure.
BACKGROUND
In 2003, the number of deaths due to malignant mesothelioma in Japan was 878; however, only 85 cases of mesothelioma due to asbestos exposure were authorized for compensation. The reasons for this discrepancy require evaluation.


METHODS
We examined medical records, X-rays, and pathology results to evaluate mesothelioma cases in Japan between 2003 and 2005; used a questionnaire to identify occupational and environmental histories, and determined the concentration of asbestos fibers in pathology specimens.


RESULTS
We identified 442 definite cases of malignant mesothelioma with a median age of 68 years. There were 316 malignant mesothelioma cases with occupational asbestos exposure, 12 cases with neighborhood exposure and 5 cases with likely domestic exposure. Most (78%) of the 87 cases exceeded 1,000 asbestos particles per gram of dry lung tissue.


CONCLUSIONS
We conclude that 79.2% of cases of mesothelioma in Japan in recent years were caused by asbestos exposure.
Kishimoto
Takumi
T
Okayama Rosai Hospital, Japan. nakisimt@okayamah.rofuku.go.jp
Gemba
Kenichi
K
Fujimoto
Nobukazu
N
Aoe
Keisuke
K
Kato
Katsuya
K
Takeshima
Yukio
Y
Inai
Kohki
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001194:Asbestos / Q000633:toxicity*; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D008499:Medical Records; D008654:Mesothelioma / Q000145:classification / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality; D008875:Middle Aged; D009369:Neoplasms / Q000145:classification / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality; D016273:Occupational Exposure / Q000009:adverse effects*; D012189:Retrospective Studies; D011795:Surveys and Questionnaires; D014942:Workers' Compensation; D055815:Young Adult
D001194:Asbestos