Asbestos exposure is linked to the development of all major histological subtypes of lung cancer, as well as mesothelioma, a rare and aggressive tumor that originates from pleural mesothelium. It is estimated that 4% to 12% of all lung cancers are associated with occupational exposure to asbestos fibers.
“Asbestos is a well-recognized occupational carcinogenic agent and is responsible for the leading cause of occupational cancer-related deaths, with asbestos-related lung cancer and mesothelioma being the primary contributors,” said Wang-Zhong Li, PhD, a Fellow at The First Affiliated Hospital of Guangzhou Medical University, China, during the session on Global Perspectives of Lung Cancer Across the Care Continuum at the 2024 World Conference on Lung Cancer.
Dr. Li and colleagues assessed the global burden of asbestos-related lung cancers and the tends in outcome using data from the Global Burden of Disease Study 2021, the International Ban Asbestos Secretariat, and other sources. They used age-standardized mortality rate and average annual percentage change (AAPC) as the primary outcome measures.
Age-standardized mortality rate (ASMR) is a statistical method used to compare health indicators between populations. It’s calculated by applying the age-specific mortality rates of a population to a standard population. The ASMR is a weighted average of the age-specific mortality rates per 100,000 people.
“In 2021, more than 200,000 deaths attributed to asbestos occurred,” Dr. Li said. Of these asbestos-related deaths, 183,000 occurred in men; more than 189,000 of these deaths were due to lung cancer.
The global cohort’s ASMR was 4, with men and women having ASMRs of 8 and 1, respectively (see Fig. 1).
During the session, Dr. Li discussed the decline in average annual percentage change during the past three decades.
Despite a decrease in the total number of asbestos-related deaths from 1990 to 2021, the global age standardized rate of mortality per 100,000 people continues to increase, Dr. Li said, noting that the most significant impact on the average annual percentage change is observed in males and individuals with lung cancer.
Dr. Li and colleagues identified significant geographical variations, revealing an inverse relationship between the age-standardized mortality rate and the average annual percentage change in countries and regions with a high socio-demographic index. Overall, these trends—an increasing absolute number of deaths alongside decreasing adjusted mortality rates—are projected to persist between 2021 and 2023, based on modeling analyses conducted by Dr. Li and his team.
“Countries with higher socio-demographic indices are more likely to implement nationwide asbestos bans. However, countries with such bans have a higher mortality burden from asbestos-related lung cancer and mesothelioma,” Dr. Li said. This was evident in 2021, just as it was in 1990.
Dr. Li did not speculate as to why countries with nationwide asbestos bans have higher mortality burdens.
An analysis of the differences in ASMR following the implementation of a national asbestos ban revealed that the positive impact of the ban on reducing country-level ASMR lags by a decade or more.
“Our research provides a comprehensive overview of the global burden of asbestos-related lung cancer and mesothelioma, highlighting significant geographical and demographic variations. Countries with asbestos bans have, historically and currently, a higher burden of these cancers,” Dr. Li said. “While these bans have reported effects on reducing the mortality burden associated with these cancers, it takes a long time for this impact to be observed.”
