An estimated 10–25% of lung cancers worldwide occur in people who have smoked fewer than 100 cigarettes in their lifetime – categorized as “never smokers.” Lung cancer in this group is more frequent in women, although this varies greatly by geographic region. Findings from the TRACERx study on pollution and lung cancer – funded in part by LCRF – were presented at the ESMO Congress last year, have undergone peer review, and were published last week.
The good news:
Scientists examined information from over 400,000 people from the UK and Asian countries, comparing rates of EGFR mutant lung cancer in areas with different levels of pollution. They found higher rates of EGFR mutant lung cancer, as well as higher rates of other types of cancer, in people living in areas with higher levels of pollution. Since this is a lung cancer more common in non-smokers, it was felt that the pollution particles were causing the lung cancer. By studying the effects of pollution in mice and human cells it is felt that inflammation from the pollution turns on the cancer process in cells that may already have some abnormalities but are asleep.
Why it’s significant:
This finding is important because previously, it was thought that the pollution itself causes changes in the DNA that result in cancer. Although this could still happen, this research suggests that it may be inflammation from the pollution that turns on the malignant process in cells that have some natural damage from aging or exposure to other substances.
How this can impact patients:
This discovery may be important in how prevention of lung cancer is approached. Reducing inflammation through diet or medications may be used as a prevention strategy in the future.
What else you should know:
We are beginning to see that progress is being made regarding understanding how lung cancer develops. It is also important for governments to continue to try and control air pollution because of the negative impact it has on the health of the world’s population.