According to the American Cancer Society, lung cancer is the leading cancer death and makes up almost 25% of all cancer deaths. About 80% of lung cancer deaths are due to smoking, making it the leading risk factor for the disease. It is very rare for non-smokers to have small cell lung cancer, but a new study has pointed out another risk factor that might increase it.
New research claims that air pollution could be a major risk factor in developing lung cancer alongside smoking. The study opens new doors to rethinking how to treat certain cancers and prevent them. More so, it could help environmental agencies to implement stricter limits on air quality.
Air Pollution Triggers Lung Cancer in Non-Smokers by Increasing Gene Mutation Linked to the Disease
Air Pollution Particles Waking Up Old Damaged Cells
The classical knowledge of how cancer starts is when a healthy cell acquires more and more mutations in its DNA until it grows uncontrollably and becomes cancer. However, as Metro reported, scientists found cancerous mutations even in perfectly healthy tissue and many substances like air pollution seem not to damage the DNA.
The new research presented to scientists at a conference of the European Society for Medical Oncology has identified the mechanism through which air pollution triggers lung cancer in people who do not usually smoke. Researchers of the study pointed out that tiny particles from burning fossil fuels contribute to health dangers.
Professor Charles Swanton from the Francis Crick Institute in London showed that air pollution particles are waking up old damaged cells. Together with his colleagues from the institute and the University College London, they analyzed the health data of over 460,000 people in England, South Korea, and Taiwan.
They found that people exposed to pollution particles of at least PM2.5 have a higher risk of mutations in their EGFR gene, which is linked to developing lung cancer.
Researchers were able to stop cancer from forming in mice models exposed to air pollution using a drug that blocks the triggering signal in genes. Swanton remarks that their study could "pave the way for a new field of cancer prevention," given its double breakthrough not only in understanding the link between lung cancer and air pollution but also in how people develop cancer.
Study author Dr. Emilia Lim, a researcher at the Crick and UCL, said that the findings will give non-smokers an idea of how they got lung cancer. Also, it is important for many people in the world who live in areas where air pollution exceeds the WHO guidelines.
READ ALSO: Lung Cancer Patients Who Quit Smoking Even After Diagnosis Have Higher Chances of Survival Rate, Study Says
New Study Changes the Understanding of Cancer
The results of the study showed mutations are not enough to cause cancer because an extra element is needed sometimes, BBC News reported. Professor Swanton noted that it pushed scientists to rethink the understanding of how tumors begin, which leads to a new era of developing molecular cancer prevention methods.
Doctors have tested the pill interleukin-1-beta drug in people with cardiovascular diseases and serendipitously found that it can also reduce lung cancer risk. Professor Swanton told BBC that pollution is just an example of substances that could increase the risk of cancer for non-smokers and there could be hundreds in the next 10 years.
He added that smoking should also be viewed in a different light now, whether the chemicals in the tobacco cause DNA damage or its smoke could cause inflammation as well.
Interestingly, the idea that mutated DNA is not enough to cause cancer and needs another trigger was first proposed by scientist Isaac Berenblum in 1947. But thanks to the efforts of scientists, they are changing the views on how cancer develops and giving people a better understanding of the driving force behind the disease.
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