Malignant mesothelioma in Hong Kong

Population-Based Clinical Studies Using Routinely Collected Data in Hong Kong, China: A Systematic Review of Trends and Established Local Practices

Background: Routinely collected health data are increasingly used in clinical research. No study has systematically reviewed the temporal trends in the number of publications and analyzed different aspects of local research practices and their variations in Hong Kong, China, with a specific focus on research ethics governance and approval.

Methods: PubMed was systematically searched from its inception to March 28, 2023, for studies using routinely collected healthcare data from Hong Kong.

Results: A total of 454 studies were included. Between 2000 and 2009, 32 studies were identified. The number of publications increased from 5 to 120 between 2010 and 2022. Of the investigator-led studies using the Hospital Authority (HA)’s cross-cluster data (n = 393), 327 (83.2%) reported receiving ethics approval from a single cluster/university-based REC, whereas 50 studies (12.7%) did not report approval from a REC. For use of the HA Data Collaboration Lab, approval by a single hospital-based or University-based REC is accepted. Repeated submission of identical ethics applications to different RECs is estimated to cost HK$4.2 million yearly.

Conclusions: Most studies reported gaining approval from a single cluster REC before retrieval of cross-cluster HA data. Substantial cost savings would result if repeated review of identical ethics applications were not required.

Upcoming epidemic of asbestos-related malignant pleural mesothelioma in Taiwan: A prediction of incidence in the next 30 years

BACKGROUND/PURPOSE

Globally, asbestos-related diseases (ARDs) keep rising over the coming decades. The epidemic of ARDs will be a burden on public health. We aimed to predict the malignant pleural mesothelioma (MPM) incidence in the next 30 years for Taiwan based on historical asbestos consumption.

METHODS

We collected annual data on local asbestos consumption during 1939-2015 and sex-specific incidence of pleural cancer as a proxy for MPM during 1979-2013. We applied Poisson log-linear models to predict future MPM numbers under the assumption that latency periods between asbestos exposure and MPM incidence were between 25 and 45 years.

RESULTS

Asbestos consumption reached a peak in the 1980s, with a total of 668 thousand metric tons during 1939-2015. The observed number of MPM incidence increased by 9- and 6-fold in males and females during 1979-2013, with a cumulative number of 907. Given a latency period of 31 years, MPM incidences were expected to peak around 2012-2016 for males and 2016-2020 for females. In 2017-2046, the predicted total number of new MPM might reach 659 cases (95% confidence interval = 579-749); and the male to female ratios ranged from 1.8 to 2.8.

CONCLUSION

The MPM epidemic in Taiwan will likely peak in 2012-2020 as a result of local asbestos consumption. Approximately 659 new MPM cases in the next 30 years warrant an urgent need to implement a total asbestos ban and put more resources on a comprehensive surveillance, diagnosis, and follow-up health care system for ARDs.

History of Asbestos Ban in Hong Kong

As millions of immigrants moved to Hong Kong (HK) from China in the recent decades, large amount of residential housings were built in the early years and a substantial proportion of those buildings used asbestos-containing materials (ACMs). Since the number of new cases of ARDs diagnosed has increased year by year since 1990's, the remarkable increase of incidences had drawn the attention of the public and most importantly the HK government. It became one of the trigger points leading to asbestos ban in HK history. Comparatively, non-governmental organizations (NGOs), labor unions and patients' self-help organizations demonstrated a more aggressive and proactive attitude than the HK government and have played a key role in the development of asbestos banning policy in HK. After numerous petitions and meetings with the government representatives by those parties in the past decade, the HK government eventually changed its attitude and started to consider terminating the endless threat from asbestos by amending the policy, and the new clause of legislation for banning of all forms of asbestos was enacted on 4 April 2014. Other than the restriction of asbestos use, the compensation system about ARDs has also made some great moves by the effort of those parties as well. Based on the experience we learnt through the years, efforts from different stakeholders including patients' self-help organizations, NGOs, legislative councilors, and media power are absolutely essential to the success of progression and development in today's asbestos banning in HK.

Epidemiology and trend analysis on malignant mesothelioma in China

Objective

Population-based cancer registration data were used to analyze the epidemiology and trend of malignant mesothelioma in China, and the result would provide basic data for its prevention and control.

Methods

Malignant mesothelioma data in 2013 were retrieved from the database of National Cancer Registry. Malignant mesothelioma incidence and mortality were estimated using age-specific rate by urban/rural and gender according to the national population in 2013. Malignant mesothelioma data from 22 cancer registries were used for trend analysis during 2000–2013.

Results

It is estimated that there were 2,041 new malignant mesothelioma cases and 1,659 malignant mesothelioma deaths occurred in 2013. The crude incidence rate in China were 1.50/10⁶ (males 1.67/10⁶, females 1.32/10⁶), age-standardized incidence rates by Chinese standard population (ASIRC) and by world standard population (ASIRW) were 1.03/10⁶ and 1.02/10⁶, respectively. The crude mortality rate in China was 1.22/10⁶ (males 1.67/10⁶, females 1.32/10⁶), age-standardized mortality rates by Chinese standard population (ASMRC) and by world standard population (ASMRW) were 0.83/10⁶ and 0.81/10⁶, respectively. There was an increasing trend of incidence rate for malignant mesothelioma in registration areas of China during 2000–2013 with annual percentage change (APC) of 2.5% [95% confidence interval (95% CI): 0.6%–4.5%]. After age standardization, no significant differences were observed. No matter for crude mortality rates or age-standardized mortality rates, no significant differences were observed during 2000–2013.

Conclusions

Malignant mesothelioma is the major occupational and environmental neoplasm associated with asbestos exposure. The increasing incidence trend suggests that more attention should be paid on this disease.

Perspectives on refractory ceramic fiber (RCF) carcinogenicity: comparisons with other fibers

In 2011, SCOEL classified RCF as a secondary genotoxic carcinogen and supported a practical threshold. Inflammation was considered the predominant manifestation of RCF toxicity. Intrapleural and intraperitoneal implantation induced mesotheliomas and sarcomas in laboratory animals. Chronic nose-only inhalation bioassays indicated that RCF exposure in rats increased the incidence of lung cancer and similar exposures resulted in mesothelioma in hamsters, but these studies may have been compromised by overload. Epidemiological studies in the US and Europe showed an association between exposure and prevalence of respiratory symptoms and pleural plaques, but no interstitial fibrosis, mesotheliomas, or increased numbers of lung tumors were observed. As the latency of asbestos induced mesotheliomas can be up to 50 years, the relationship between RCF exposure and respiratory malignances has not been fully determined. Nonetheless, it is possible to offer useful perspectives. RCF and rock wool have similar airborne fiber dimensions and biopersistence. Therefore, it is likely that these fibers have similar toxicology. Traditional rock wool has been the subject of numerous cohort and case control studies. For rock wool, IARC (2002) concluded that the epidemiological studies did not provide evidence of carcinogenicity. Based on analogies with rock wool (read across), it is reasonable to believe that increases in lung cancer or any mesotheliomas are unlikely to be found in the RCF-exposed cohort. RCF producers have developed a product stewardship program to measure and control fiber concentrations and to further understand the health status of their workers.

Malignant mesothelioma in Eastern Asia

Relatively low numbers of malignant mesotheliomas have been reported from Eastern Asia. In order to explore the causes of this fact, the available data on mesothelioma incidence/mortality in five countries (Japan, South Korea, Taiwan, Hong Kong, and Singapore) were reviewed. Data on the industrial histories of the above countries were also examined. Mesothelioma incidence was low, despite a history of high shipbuilding and port activities, in which heavy exposure to asbestos generally has occurred. Underestimation of mesothelioma could partly explain the above discrepancy. Moreover, in some areas a sufficient latency period for mesothelioma development may have not yet elapsed, due to recent industrialization. However, other possibilities have to be considered. The cancer epidemiology in Eastern Asia differs deeply from that seen in Western countries, an indication of differences in etiologic factors of cancer as well as in co-factors. In addition, the oncogenic spectrum of asbestos is wide, and not completely defined. In a very different milieu from that of Western countries, asbestos could preferentially hit targets other than serosal membranes.

Guidelines for asbestos remediation at Italian superfund sites

Asbestos is now banned in 52 countries. Although Italy banned asbestos in 1992, up until that date it had been one of the main producer nations of asbestos and asbestos-containing materials, and asbestos-related contamination is still widespread in the country. To reduce asbestos-related health effects, Italy has adopted many laws and regulations regarding exposure thresholds and remediation tools. Even so, there are legislative gaps that are making it difficult to manage related risks especially in the operative phase. The lack of standard procedures at a national level regarding emergency shutdown and remediation as well as reference thresholds for specific risk situations creates difficulties and different actions when dealing with the cleanup of Italian asbestos superfund sites. The authors propose operative guidelines for asbestos remediation at Italian superfund sites. INAIL, the reference national organization for asbestos-related matters, acting as an advisor to a number of state, regional, and local authorities, examined the main asbestos-related risk situations in Italy and proposed the most appropriate actions to take. The detailed analysis of many actual cases of risk, in part through inspections and the management of cleanup actions at asbestos Italian superfund sites, resulted in proposals to modify existing procedures and thresholds, which were subsequently discussed with all national, regional, and local scientific bodies. After more than two years of work and discussion at a national level, INAIL-DIPIA-Asbestos Group drafted new Guidelines for Asbestos Remediation at Italian Superfund sites, and officially submitted them to the Environment Ministry. The Ministry then adopted the document in regard to all asbestos Italian superfunds. This recently released document is also a useful reference for contaminated sites at a regional and local level. The operative Guidelines for Asbestos Remediation at Italian Superfund sites may also be of use at an international level for countries that have already banned asbestos and are engaged in remediation activity and for countries that have not yet banned asbestos but wish to adopt risk prevention measures.

Are current or future mesothelioma epidemics in Hong Kong the tragic legacy of uncontrolled use of asbestos in the past?

Inhaled asbestos fibers may contribute to three-fourths of malignant mesotheliomas diagnosed in men and almost 40% of cases diagnosed in women. Bans on the manufacture and sale of amphibole asbestos fibers are expected to reduce the incidence of mesothelioma, but the long latency period from initial exposure to clinical disease means that people exposed before bans were enacted will continue to develop asbestos-related mesotheliomas as they age. Tse et al. (p. 382) used historical data on asbestos consumption and mesothelioma diagnoses to predict future mesothelioma trends in Hong Kong. Asbestos use peaked during a construction boom in the early 1960s and subsequently declined by > 90% following a ban on the sale and import of crocidolite and amosite asbestos in 1996, whereas mesothelioma diagnoses in men increased from a single case in 1972–1976 to 63 cases in 2002–2006 (corresponding to crude incidence rates of 0.09 and 3.86 cases/million men, respectively). Assuming an average latency of 42 years, the authors predict that incidence rates will peak in 2009 and that diagnoses will peak in 2014. However, they caution that ongoing use of chrysotile asbestos and the release of asbestos fibers from older buildings during demolition or renovation may slow the projected decline. [corrected]

Malignant peritoneal mesothelioma

Malignant mesothelioma is a highly aggressive neoplasm. The incidence of malignant mesothelioma is increasing worldwide. Diffuse malignant peritoneal mesothelioma (DMPM) represents one-fourth of all mesotheliomas. Association of asbestos exposure with DMPM has been observed, especially in males. The great majority of patients present with abdominal pain and distension, caused by accumulation of tumors and ascitic fluid. In the past, DMPM was considered a pre-terminal condition; therefore attracted little attention. Patients invariably died from their disease within a year. Recently, several prospective trials have demonstrated a median survival of 40 to 90 mo and 5-year survival of 30% to 60% after combined treatment using cytoreductive surgery and perioperative intraperitoneal chemotherapy. This remarkable improvement in survival has prompted new search into the medical science related to DMPM, a disease previously ignored as uninteresting. This review article focuses on the key advances in the epidemiology, diagnosis, staging, treatments and prognosis of DMPM that have occurred in the past decade.

Substituição de amianto por silicato de alumínio e grafite expansível em compósito de poliuretano utilizado em motor-foguete

Compósitos de poliuretano e amianto (liner) são utilizados como revestimento interno em paredes de motor-foguete, conferindo proteção térmica e garantindo a adesão entre o propelente e as paredes do motor. No entanto, o uso do amianto tem sido restringido devido à sua toxidade. No presente trabalho, o amianto foi substituído por um silicato de alumínio hidratado (SA) e pelo grafite expansível (GE) em diferentes teores no liner. Resultados de análise termogravimétrica (TG) mostraram que a estabilidade térmica do liner praticamente não é afetada pela substituição das cargas, embora a energia de ativação (Ea) obtida para a decomposição tenha mudado, mostrando maiores valores para as amostras contendo as cargas SA e GE. A análise termomecânica (TMA) mostrou que o coeficiente de expansão térmica linear do liner contendo SA foi menor que aquele encontrado para o liner contendo amianto. O liner contendo a carga SA também apresentou os maiores valores de tensão nos testes mecânicos de tração.

Malignant mesothelioma: global incidence and relationship with asbestos

Mesothelioma incidence varies markedly from one country to another. The highest annual crude incidence rates (about 30 cases per million) are observed in Australia, Belgium, and Great Britain. A lot of data indicate a relationship between mesothelioma and asbestos. The hot areas for mesothelioma exactly correspond to the sites of industries with high asbestos use, such as shipbuilding and asbestos-cement industry. However, in many countries with high asbestos consumption, mesothelioma incidence is low. The reasons for this fact are not clear. The latency periods elapsing between first exposure to asbestos and development of mesothelioma are mostly longer than 40 yr. An inverse relationship exists between intensity of asbestos exposure and length of the latency period. Mesothelioma generally develops after long-time exposures to asbestos. Some recent studies show that the risk increases with the duration of exposure. Possible co-factors in the pathogenesis of asbestos-related mesothelioma include genetic predisposition, diets poor in fruit and vegetables, viruses, immune impairment, recurrent serosal inflammation. The study of co-morbidity in mesothelioma could give an insight into the pathogenesis of the tumor. While a levelling-off in mesothelioma incidence has been registered in some countries, a worsening of the epidemic is predictable in large parts of the world.