Up to 20% of patients with lung cancer have never smoked. A new discovery could help doctors identify these high-risk individuals in advance and monitor them more intensively, researchers reported.
A rare inherited mutation in the Epidermal Growth Factor Receptor gene is associated with an overall 25-fold increased risk of lung cancer, according to a study that looked at data from more than 3.3 million people in the 23andMe genetic database.
The mutation, called EGFR T790M, was associated with 10 times higher odds of developing lung cancer among smokers.
Among never-smokers, carriers of the mutation were more than 60 times as likely to develop lung cancer as people without it, the researchers reported in Science.
"Today, lung cancer screening is driven almost entirely by smoking history,” study leader Dr. Jaclyn LoPiccolo of the Dana-Farber Cancer Institute in Boston said in a statement.
“Our findings raise the possibility that, in the future, screening could also be dictated by inherited genetic risk.”
The variant was not linked to any of 17 other common cancers studied, suggesting that its effects may be largely limited to lung cancer.
EGFR T790M was first identified in 2005 in a European family with multiple cases of lung cancer, according to the researchers, who say it has since been found in other families with unusually high rates of the disease.
"For years we've known that some families inherit a markedly increased risk of lung cancer, but because this variant is so rare, we've never been able to accurately measure that risk,” study co-author Dr. Pasi Jänne, also at Dana-Farber, said in a statement.
“By studying more than three million people, we were able to demonstrate just how strongly this inherited mutation is associated with lung cancer."
