Although lung cancer and related cancer deaths decreased in the world’s 10 most populous countries from 1990 to 2019, these positive statistics may not address trends in mortality linked to tobacco use, air pollution, and asbestos exposure, according to a recent study published by Jani et al in eClinicalMedicine. The findings suggested that these areas need ongoing policy measures and research to further reduce mortality rates.
Background
Lung cancer is the leading cause of cancer-related mortality across the world. As a result, raising awareness about all tracheal, bronchial, and lung cancer risk factors on a global scale may be critical.
"This research allows us to better assess global trends and highlight areas where public health policies and further research are needed to tackle [tracheal, bronchial, and lung] cancers," emphasized senior study author Gilberto Lopes, MD, Chief of the Division of Medical Oncology and Associate Director of the Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine.
Study Methods and Results
In the study, the investigators analyzed tracheal, bronchial, and lung cancer data from the open-source Global Burden of Disease database.
The investigators found that there was an overall 8% decrease in tracheal, bronchial, and lung cancer mortality over a period of three decades. While tobacco-related mortality declined, it continues to represent the majority of cancer cases. However, mortality linked to particulate matter air pollution has risen globally, and asbestos exposure remains a critical concern, especially in the United States.
The percentage of tracheal, bronchial, and lung cancer–related deaths linked to tobacco use declined from 72% in 1990 to 66% in 2019. Nonetheless, certain countries such as China and Indonesia are still experiencing rising tobacco-related cancer mortality. Moreover, the global mortality rate among women increased by 2%, whereas men still accounted for about three-quarters of tobacco-related deaths.
These trends indicated the need to continue public health measures to reduce tobacco use. Despite the progress in reducing tobacco-related lung cancer mortality, the burden remains significant.
“We are going on the right path, but [we] feel that the final end of the tunnel is far away,” noted lead study author Chinmay Jani, MD, a clinical fellow in Hematology and Oncology at the Sylvester Comprehensive Cancer Center.
The investigators revealed that air pollution now accounts for nearly 20% of global tracheal, bronchial, and lung cancer mortality. Overall deaths linked to air pollution decreased between 1990 and 2019, but deaths associated directly with ambient particulate matter increased by 11%. In China, the rate was twice the global average. As a result, the investigators called for stronger global policies to address this rising public health threat. They also stressed the need to increase awareness in regions like India, where burning solid waste is common and public awareness of air pollution’s risk remains low.
“The association between lung cancer mortality and air pollution is still controversial, but there is an increasing body of evidence that there is a connection here that needs to be paid attention to,” indicated co–study author Estelamari Rodriguez, MD, MPH, Co-Lead of the Thoracic Site Disease Group at the Sylvester Comprehensive Cancer Center. “This paper provides further evidence that this is not an issue limited to one country; it is a global phenomenon,” she continued.
“The government is trying to provide the resources and facilities so that solid waste is disposed of in other ways, but the public awareness is not as strong among the general population,” Dr. Jani added.
Additionally, the investigators conducted a comprehensive evaluation of asbestos exposure, focusing on granular data related to these three critical risk factors. Regardless of significant progress in banning asbestos, asbestos-related tracheal, bronchial, and lung cancer deaths in the United States remain nearly double the global average.
“Even though we have banned asbestos, we need to look more into the causes of exposure,” Dr. Jani urged.
Conclusions
The investigators underlined the need for continued research to better understand the mechanisms driving tracheal, bronchial, and lung cancer, including how various risk factors contribute to molecular changes in cancer cells.
“Understanding all these risk factors and how they are impacting the molecular alterations of lung cancer is important, because then we can have targeted, precision medicine for [patients with] lung cancer based on the risk factors that they had,” Dr. Jani highlighted.
The findings necessitated revising current screening guidelines, which are primarily focused on tobacco exposure. The investigators also illuminated an alarming increase in lung cancer diagnoses in younger patients—especially women with low tobacco exposure—raising concerns about the adequacy of current screening practices.
“How can we change screening approaches to be able to diagnose younger patients when they can be cured? Currently, young patients with a cough are rarely considered at risk for lung cancer,” Dr. Rodriguez underscored. “Their symptoms are often overlooked, even though proper screening could have detected the condition earlier,” she concluded.
Disclosure: For full disclosures of the study authors, visit thelancet.com.
