Five European countries rank highest for lung cancer risk attributable to air pollution among those aged 50 to 69 years, according to research presented by Berg et al in the Presidential Symposium Plenary Session at the International Association for the Study of Lung Cancer (IASLC) 2021 World Conference on Lung Cancer (Abstract PL02.07).

Although tobacco smoke is clearly a major cause of lung cancer, a recent analysis determined that worldwide, air pollution accounts for 14% of lung cancers, according to data reported by Christine D. Berg, MD, who is affiliated with National Institutes of Health Clinical Center. The causal evidence of a link between air pollution and lung cancer has been building for decades, but the risk varies widely in different regions of the world depending on the age of the population, the amount of tobacco smoking over time, and the amount of air pollution in the country. Dr. Berg and coresearcher Joan H. Schiller, MD, an Adjunct Professor at the University of Virginia and a Board Member of the Lung Cancer Research Foundation, sought to better understand the worldwide variability in air pollution attributable to lung cancer.

Literature Review and Results

The researchers conducted a review of the literature on the burden of indoor and outdoor air pollution and assessed the burden of lung cancer by country from air pollution by querying The Global Burden of Disease Compare publicly accessible database. Lung cancer mortality was chosen as the endpoint in an age-standardized population of 100,000. Because the incidence of lung cancer increases with age, two age groups were selected: ages 50 to 69 years, and 70 years and older. Both sexes were combined in the analysis. The top 15 countries in each age group were ranked, and then the team compared changes in relative country ranking by age group.

According to the analysis, Serbia (36.88 per 100,000), Montenegro (34.61 per 100,000), North Macedonia (30.67 per 100,000), Bosnia/Herzegovina (30.64 per 100,000), and Poland (27.97 per 100,000) ranked highest for risk of lung cancer attributable to air pollution among those aged 50 to 69.

Among the 70 and older group, China (98.55 per 100,000), Mongolia (71.11 per 100,000), North Korea (63.45 per 100,000), Laos (62.07 per 100,000), and Montenegro (61.80 per 100,000) ranked highest.

“For comparison, in the United States, the number of lung cancer deaths per 100,000 attributed to air pollution in [those] aged 50 to 69 is 3.91 and is 13.62 for [those aged] 70 and older,” Dr. Berg said. The Balkans, Poland, Turkey, China, and some southeast Asian countries had the highest attributable risks; Serbia had the highest number of attributable deaths in the 50 to 69 age group, whereas China had the highest in the 70 and older age group.

“Patterns of cigarette smoking and amounts of pollution from fossil fuel energy sources are most likely the primary drivers of the variability in risk attributable to lung cancer,” said Dr. Berg. “As the tobacco epidemic is addressed, we also need to address other preventable causes of lung cancer.”