A new study is further evidence that asbestos bans are not a quick fix for the global problem of malignant mesothelioma incidence.
Researchers in China and the US just released a worldwide research study on the asbestos cancer. The study included 21 regions in 195 countries and territories and spanned 27 years.
The authors say mesothelioma incidence does decrease after asbestos bans. But the decrease can take decades. In the meantime, they say many countries need to do a better job of tracking and managing mesothelioma cases.
Asbestos and Mesothelioma Incidence
Malignant mesothelioma is an aggressive cancer with a poor prognosis. Exposure to asbestos is its only known cause. People with mesothelioma often die of this cancer in less than a year, even with standard of care treatment.
Mesothelioma incidence is highest in people who have worked around asbestos. Asbestos is a mineral that used to be prized for its strength, heat resistance, and abundance. Manufacturers used it in hundreds of products from construction supplies to personal care.
After scientists made the connection between asbestos and mesothelioma incidence, some companies stopped using it. Sixty countries have now banned asbestos. Countries that mined and exported asbestos or that used a lot of asbestos have the highest rates of mesothelioma.
Calculating the Global Burden of Malignant Mesothelioma
Researchers from several Chinese Universities and Boston’s Dana Farber Cancer Institute used data from the Global Burden of Disease 2017 database. They focused on people diagnosed with mesothelioma between 1990 and 2017. The patients came from 21 regions in 195 countries and territories.
In addition to mesothelioma incidence, the researchers looked at the ages and genders of patients, the sociodemographic level of their area, and how those numbers changed over time.
More than 34,600 people received mesothelioma diagnoses in 2017. Almost 30,000 of people died of mesothelioma that year. That is an increase in mesothelioma incidence from 1990. That year, just over 21,200 people were diagnosed with mesothelioma. There were 17,406 deaths.
The number of mesothelioma patients over 70 went up. The number of mesothelioma patients younger than 50 went down. Poorer regions had more per capita cases than wealthier areas.
In countries that instituted asbestos bans, mesothelioma incidence went down. But it took about 20 years for the effect to show.
Lead author Zhen Zhai writes,“For example, in Italy, a complete ban on asbestos went into effect in 1992; incident cases increased from 1409 individuals in 1990, peaked in 2015 after 23 years of the asbestos ban, then decreased from 1820 individuals in 2015 to 1746 individuals in 2017.”
About 2,500 Americans are diagnosed with mesothelioma each year. Asbestos is heavily regulated in the US, but there is no asbestos ban.
Zhai, Z, et al, “Assessment of Global Trends in the Diagnosis of Mesothelioma From 1990 to 2017”, August 2, 2021, JAMA Network Open, https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2782981