Tobacco has long been accepted as the key factor in the development of lung cancer. As smoking rates have declined in many countries, other influences are attracting more attention. Environmental factors fueled by climate change, indoor pollutants, vaping and smoking cannabis, and military conflicts are just a few of the emerging contributors to the pathogenesis and progression of lung cancer.
“Lung cancer is no longer considered solely a smoker’s disease,” said Roselle De Guzman, MD, medical oncologist and Associate Professor of Medicine at Manila Central University-FDT Medical Foundation Hospital, Manila, Philippines. “We are more aware now that there are other important factors that need to be addressed.”
Dr. De Guzman will discuss what is known about the effects of indoor environmental exposures to radon, arsenic, asbestos, cooking fuels, and other pollutants during a special plenary session Unmasking Lung Cancer: Exploring the Rising Influence of Non-Tobacco Factors on Monday, September 9, from 17:00 to 18:30 PDT in the Plenary Hall at the San Diego Convention Center.
17:00-18:30 PDT, Monday, September 9
Plenary Hall, San Diego Convention Center
Unmasking Lung Cancer: Exploring the Rising Influence of Non-Tobacco Factors
During a special plenary session, experts will outline the connection between exposure to non-tobacco elements and lung cancer development.
Non-tobacco factors are not new, but the attention they are receiving is, Dr. De Guzman said.
“It can be difficult for researchers, epidemiologists, and clinicians to understand well the connection between non-tobacco factors and lung cancer risk because of the long latency period between exposure and the development of lung cancer,” she said. “We are not really trained to include environmental exposures in patient history-taking. It can be challenging to isolate the impact of non-tobacco factors in lung cancer risk.”
Research can be difficult when long-term data are not available. Vaping is a relatively new pulmonary insult and the impact of smoking cannabis isn’t widely documented.
“Vaping and other heated tobacco products are being introduced into the market and being used at higher rates,” said Pamela Ling, MD, MPH, Stanton Glantz Distinguished Professorship in Tobacco Control, Director of Center for Tobacco Control Research and Education, Professor of Medicine, and Co-leader of the cancer control program at the University of California, San Francisco, Helen Diller Family Comprehensive Cancer Center.
“And along with cannabis legalization in many states, we also see increasing rates of cannabis and tobacco co-use in some groups. That raises questions about the effects of smoking anything,” she said.
Animal and mechanistic in vitro studies suggest that burning and inhaling any plant product carries cardiovascular and cancer risks, Dr. Ling said. However, the epidemiologic research is limited in terms of duration of exposure. Additionally, legal barriers also hinder research, particularly surrounding cannabis, which is currently classified as a Schedule I drug with a high potential for abuse by the U.S. Drug Enforcement Administration (DEA).
Military conflict also presents an increased risk of exposure to carcinogens and other pollutants, and modern warfare has become an increasingly urban occurrence with the conflicts in Gaza and Ukraine being two recent examples
“I worked in Kyiv as a cancer technical officer to the World Health Organization and the number of tons of environmental harms thrown into the atmosphere is far higher than in areas where there are no bombs falling,” said Felipe Roitberg, MD, medical oncologist and Coordinator for Research, Innovation and Health Technology Assessment for the Brazilian University Hospitals Network-Rede Ebserh, Brasilia, Brazil.
“If you go to Gaza, there are tons, megatons, of bombs dropped in a short time,” he continued. “People have no escape from breathing particulates thrown into the air. We must pay attention to the consequences, not only of the bombs or bullets landing on your chest, but also the particulates, invisible compounds might put their lungs and lives at risk.”
Climate change is another novel contributor to lung cancer. Not only do environmental changes contribute to wildfires and potentially toxic smoke exposures over broad areas, but climate-related disasters interfere with cancer care.
“As more people are being affected by climate-driven extreme weather events and disasters, there is an increasing awareness of these environmental causes of lung cancer,” said Leticia Nogueira, PhD, MPH, Scientific Director of Health Services Research, American Cancer Society. “And if you already have lung cancer, you might have the best oncologist, the best equipment, the best treatment, but if there is a disaster that impacts your access to care, if there is a disruption to your treatment, that is a factor that can affect your outcome.”
