by Air pollution and traditional herbal medication could be important risk factors that contribute to the development of lung cancer in humans without smoking, a groundbreaking new study has found.
While smoking is an essential risk factor for lung cancer, the rates of malignancy seem to be used by those who have never smoked, even if tobacco consumption drops worldwide.
Earlier studies have shown that lung cancer affects disproportionately non -smoking women, especially those with Asian ancestors, and is more common in East Asia than in Western nations.
Now, a new study published in the magazine on Wednesday Nature, provides convincing evidence that air pollution and herbal medication could be behind genetic mutations associated with the development of lung cancer in non -smokers.
“We see this problematic trend that smokers never get lung cancer, but we didn’t understand why,” said Ludmil Alexandrov, author of the University of California San Diego.
“Our research shows that air pollution is strongly associated with the same types of DNA mutations that we typically associate with smoking.”
Most studies on the prevalence of lung cancer have not separated data from smokers from non -smokers, which only provides limited insights into potential causes in these patients.
The latest study collected data from Never smokers worldwide and used genomics to find environmental factors that are likely behind these types of cancer.
“This is an urgent and growing global problem that we understand about never smokers,” said Maria Teresa Landi, co-author of the study by the US National Cancer Institute.
While earlier studies have shown a potential connection between air pollution and lung cancer in never-smokers, new research continues through a genomic connection.
In this comprehensive study, scientists analyzed pulmonary tumors from 871 never smokers, who lived in 28 regions with different air pollution level in Africa, Asia, Europe and North America.
The researchers used genome sequencing methods to identify different patterns of genetic mutations that act like molecular fingerprints of previous exposures.
Then compared the genomic data with pollution estimates based on satellite and ground measurements of fine particles.
This helped them to estimate the long -term exposure of patients for air pollution.
The study showed that smokers who lived in dirty environments had never significantly more mutations in their lung tumors, especially in the species that directly promote cancer development.
Scientists also found more molecular signatures in this group associated with cancer and serve as a recording of all previous exposure to mutation -causing environmental factors.
For example, these people had almost four times an increase in a mutation signature molecule associated with tobacco smoking, and an increase in the signature associated with aging by 76 percent.
“We see that air pollution is associated with an increase in somatic mutations, including those that fall under known mutation signatures that are attributed to smoking and aging tobacco,” said Marcos Díaz-Gay, co-author of the study.
Scientists found that the more pollution someone was exposed, the more mutations were found in their lung tumors and larger signs of their cells that accelerated.
Another environmental risk that was dissolved by the study was Aristolochinic acid, a well -known cancer -related chemical that occurs in some traditional Chinese and Ayurvedic herbal medication.
This chemical, which was extracted from plants from the family of births, was found with a signature mutation in lung tumors of never smokers from Taiwan.
Although the intake of this plant chemical was previously associated with bladder, intestinal, kidney and liver cancer, the latest study reports the first to report evidence that it can contribute to lung cancer.
“This raises new concerns about how traditional remedies could unintentionally increase the risk of cancer,” said Dr. Landi. “It also offers a possibility for public health for cancer prevention, especially in Asia.”
The study also found a fascinating new mutation signature, which never occurs in the lung tumors of most of the most of the people, but is missing from smokers.
“We still don’t know what’s going on,” said Dr. Alexandrov.
“This is something completely different, and it opens up a completely new area of investigation.”
