A team from the American Cancer Society and the Rollins School of Public Health at Emory University (United States) has identified a series of metabolic alterations that could explain the link between prolonged exposure to air pollution and the future risk of developing lung cancer.
The work, published in the journal "Nature Communications," notes that these changes in metabolism were detectable several years before participants were diagnosed with lung cancer, opening the door to new lines of research, early screening, and disease prevention strategies.
Although air pollution is recognized as one of the main environmental causes of lung cancer, little is still known about the modifications that occur in the body after that exposure and that ultimately trigger harmful health effects.
To delve deeper into this issue, scientists studied more than 1,100 metabolites in blood samples from 1,357 individuals who did not have cancer at the time of extraction. Of them, 671 were diagnosed with lung cancer between the sample collection and the year 2015. The majority of participants were white (96%), former smokers (59%), and had been exposed to secondhand smoke during childhood (70.5%).
The analysis revealed modifications in metabolites associated with greater chronic exposure to air pollution. These variations in the body's usual chemistry were related to processes of inflammation, oxidative stress, detoxification, and energy metabolism, all linked to an increased risk of lung cancer.
According to the authors, these biological changes induced by air pollution could serve as a basis for the future design of blood biomarkers capable of identifying individuals at higher risk of lung cancer and thus strengthen public health policies focused on prevention.
Relevance of the findings
Dr. Ying Wang, an epidemiologist and principal research scientist at the American Cancer Society, as well as the principal co-author of the work, reminds us that air pollution is classified as a human carcinogen and that, in epidemiological studies, the relationship with lung cancer tends to be more intense in those who have never smoked.
"This indicates to us that something significant is happening at a biological level, but we still do not understand the mechanisms. Studies like this, which analyze measurable changes in the organism years before a diagnosis, are the key to beginning to understand this issue," he detailed, emphasizing the importance of research.
For his part, the associate professor of environmental health at the Rollins School of Public Health and principal co-author of the study, Donghai Liang, recalls that, although smoking remains a determining risk factor for lung cancer, a relevant number of cases appear in people who have never smoked or who, despite having smoked, do not meet the criteria to undergo screening programs.
"Understanding risk factors unrelated to smoking, such as air pollution, is fundamental for the prevention and early detection of cancer," he highlighted.
In this sense, he stressed that if future research confirms these results, it could be possible to use these metabolic markers to locate individuals with a higher likelihood of developing the disease and assess whether exposure to air pollution should be incorporated into prevention and early detection strategies.