Malignant mesothelioma in Hong Kong

Summary Malignant mesothelioma (mesothelioma) is rare. We conducted the first systematic study of the epidemiology of mesothelioma in Hong Kong from 1988 to May 2002 by reviewing medical records. Mesothelioma patients were identified from the database of 12 out of 20 hospitals that would have admitted mesothelioma patients territory-wide. These 12 hospitals served 73% of the total hospital bed-years of the 20 hospitals. We identified 67 mesothelioma patients. The estimated annual incidence was one per million, which was similar to the background incidence of one to two per million among Caucasians. Occupational history was available in 43 subjects. Three quarters of mesothelioma patients with available occupational history had occupational asbestos exposure. Restricting analysis to 48 patients with accessible medical records and using 67 occupational asbestosis patients for comparison, the epidemiology of mesothelioma in Hong Kong shares similarities with the literature: mean age of 63 years upon diagnosis, mean latency of 46 years, median survival of 9.5 months, male predominance, selective presentation among women, high prevalence among workers in ships and dockyards, predominantly epithelioid type, lower prevalence of asbestos bodies, and negative association with pleural plaques. Asbestos consumption in Hong Kong rose in the 1970s and peaked in early 1980s and late 1990s. Hong Kong may encounter an epidemic of mesothelioma in the 2010s if effective occupational asbestos control measures are not in place. & 2005 Elsevier Ltd. All rights reserved. ARTICLE IN PRESS KEYWORDS Asbestos; Environmental exposures; Epidemiology; Mesothelioma; Occupational exposures 0954-6111/$ - see front matter & 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.rmed.2005.04.017 $The authors have neither received any financial support for this study nor been involved with any organization with financial interest in the subject matter. Corresponding author. Yaumatei Chest Clinic, 2/F, Yaumatei Jockey Club Polyclinic, 145, Battery Street, Kowloon, Hong Kong SAR, China. Tel.: +852 23885939; fax: +852 23743575. E-mail addresses: ymtcc@dh.gov.hk, kcchanghome@hotmail.com (K.C. Chang). 1 On behalf of the Hong Kong Thoracic society Introduction Malignant mesothelioma (mesothelioma) arises from mesothelial cells. The plasticity of mesothelial cells gives rise to three histological types: epithelioid, sarcomatoid and biphasic. The epithelioid type is the most common, with reported prevalence of 60–70% in most series.1 Approximately 80% of mesothelioma cases had past asbestos exposure.2 Wagner presented the first piece of evidence implicating asbestos in the pathogenesis of mesothelioma in a study of South African miners in 1960.3 Other implicated causes of mesothelioma include simian virus-40 (SV40),4 radiotherapy or thorium dioxide use,5,6 erionite fibres,7 chronic pleural inflammation,8 and chemical carcinogens.9