Researchers from the Francis Crick Institute and University College London used patient charts, animal studies and sample collection to explore how lung cancer is linked to air pollution from exhaust fumes from burning fossil fuels.
They presented the results of their study, which has not yet been published in a specialist journal, on Saturday at the annual meeting of the European Society for Medical Oncology in Paris. Cancer researcher Charles Swanton of the Francis Crick Institute, who was involved in the study, said a link between air pollution and an increased risk of lung cancer has long been suspected. “But we didn’t really know if the pollution directly causes lung cancer – and if so, how.”
Increased risk from fine dust
It has long been thought that exposure to carcinogens, such as those found in cigarette smoke or exhaust fumes, causes DNA mutations that lead to cancer. According to Swanton, this does not fit with the fact that research has shown that on the one hand DNA mutations can occur without causing cancer, and on the other hand that most carcinogenic substances in the environment do not cause mutations.
Swanton and his colleagues evaluated the files of more than 460,000 patients in England, South Korea and Taiwan. The analysis showed that people who are more exposed to air pollution with particulate matter of particle size PM2.5 have an increased risk of mutations in the EGFR gene, Swanton said.
age and air pollution
In the laboratory, his research team showed in mice that the PM2.5 particles caused changes in the EGFR gene and the KRAS gene, both of which are associated with lung cancer. Finally, the research team examined nearly 250 lung samples from people who had never been exposed to air pollution or tobacco smoke. Although their lungs were healthy, 18 percent of the samples had mutations in the EGFR gene and 33 percent had mutations in the KRAS gene.
“They just sit there,” Swanton said of the genetic changes, which he says increase with age. “On their own, they probably aren’t enough to cause cancer.” However, if a cell is exposed to air pollution, for example, this can trigger “a wound healing reaction” with inflammatory processes, Swanton explained. If the affected cell is affected by a corresponding gene mutation, cancer develops.
Antibodies could prevent lung cancer
Apart from the explanation for the development of lung cancer, Swanton and his colleagues also developed an approach to prevent lung cancer. In experiments with mice, they showed that the messenger substance interleukin 1 beta, which triggers the inflammatory process, can be stopped by an antibody.
This can prevent lung cancer from developing in advance, Swanton said. He hopes that on this basis “molecular cancer prevention” can be developed, for example in the form of a tablet that people can take daily as a precaution.
Cancer researcher Suzette Delaloge, who was not involved in the study, said the study was “a pretty important step for science – and for society, I hope.” It opens “a huge door both for knowledge and for new ways of preventing” cancer, Delalog said.
Source: Nachrichten
