Follow-up – WAA
A team of doctors has discovered a “worrying factor” that may increase the risk of lung cancer in non-smokers.
Although smoking is the leading cause of cancer, researchers and public health experts have not been able to identify a clear link that “explains why non-smokers are diagnosed with the disease.”
In this regard, the research, presented at the International Association for the Study of Lung Cancer (IASLC), found that exposure to small particles from car exhaust fumes and burning wood can increase the risk of a DNA mutation “known to stimulate lung tumors.”
The research team at the British Columbia Cancer Research Institute in Vancouver, Canada, collected data from 255 lung cancer patients who had never smoked, including where they had lived since birth.
Pollution levels in the neighborhoods where they lived were then analyzed, using satellite data, air pollution forecasts and ground measurements within a 10-kilometer area.
The team obtained annual pollution exposure data dating back to 1996 when accurate air pollution information became available globally.
The study also analyzed changes in patients’ DNA that may be linked to an increased risk of lung cancer, including an EGFR mutation, which speeds up the activity of a protein called the human growth factor receptor (EGFR), which helps cells grow and divide.
The researchers found that patients diagnosed with stage IV lung cancer were more likely to have EGFR mutations than those without the disease.
But they also found that women were more likely to have these EGFR mutations if they were exposed for at least 3 years to pollution particles (smaller than 2.5 micrometers), known as PM2.5, regardless of whether the woman smoked or not.
But these associations were not evident in men who had never smoked.
Despite its small size, PM2.5 is believed to cause inflammation in the lungs that can awaken normally inactive cells, leading to genetic mutations that cause cancer.
The research team says more research is needed to evaluate air pollution as a risk factor for lung cancer.
“The results suggest a potential effect of exposure to PM2.5 on lung cancer incidence in people who have never smoked, especially among women,” he wrote.
The International Agency for Research on Cancer (IARC) classified outdoor air pollution and its main component, PM2.5 particles, as a Group 1 carcinogen in 2013, indicating that they cause lung cancer.
Source: Daily Mail