People who have never smoked in their lives can also develop lung cancer due to air pollution. Experts have found that small particles in the air that derive from the combustion of fossil fuels are linked to a previously overlooked cancer-causing mechanism in lung cells.
EGFR is a gene seen in about 50% of lung cancer patients who have never smoked. Experts relied on human and laboratory research on mutations In EGFR to assess its link to air pollution. Nearly half a million people living in England, South Korea, and Taiwan were monitored to analyse their exposure to increasing concentrations of airborne particulate matter (PM) 2.5 micrometres (Im) in diametre.
The laboratory study showed that the pollutant particles (PM2.5) promoted rapid changes in airway cells with mutations in EGFR and KRAS - another gene linked to lung cancer. Air pollution was noted to drive airway cells to a cancer stem cell-like state.
Experts think these mutations being present in normal lung tissue can also be a likely consequence of ageing. But, when lung cells with these mutations are exposed to polluted air, more cancers occur more quickly in comparison to mutations not exposed to pollutants. The team is trying to figure out why some mutated lung cells become cancerous when exposed to air pollution and others don't.
The study at the Francis Crick Institute and University College London suggests that these are the same particles linked to climate change. Once they enter the body, they promote cancerous changes in airway cells. This data is linking the importance of addressing climate health to improving human health.
"The risk of lung cancer from air pollution is lower than from smoking. But, we have no control over what we breathe," said Charles Swanton, one of the authors. He added that more people are exposed to unsafe levels of air pollution than to toxic chemicals in cigarette smoke.
Scientists think the particles typically found in vehicle exhaust and smoke from fossil fuels are associated with non-small cell lung cancer (NSCLC) risk. This accounts for over 250,000 cancer deaths across the world every year.