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Genetic mutation increased risk for lung cancer among women, never-smokers
A rare germline T790M mutation of the epidermal growth factor receptor gene puts female carriers and those who never smoked at considerably higher risk for developing lung cancer than the average heavy smoker, according to recent findings.
“Fortunately, the mutation, which is extremely rare, can be detected by a blood test,” Adi Gazdar, MD, professor of pathology at UT Southwestern, said in a press release. “This is a very rare inherited mutation in the general population, but because it confers a greatly increased risk of developing lung cancer, it is present in about one in every 100 lung cancer cases.”
Adi Gazdar
In the study, researchers sought to characterize the clinical traits and smoking status of lung cancer cases with this germline mutation, as well as family members not affected by lung cancer. They followed a family with germline T790M EGFR mutations for five generations (14 individuals) and analyzed their findings combined with data acquired from a literature search (15 individuals).
The researchers found that the mutations were present in roughly 1% of non–small cell lung cancer cases and in fewer than one in 7,500 participants without lung cancer. Adenocarcinomas comprised most of the sporadic and germline T790 mutations, and the development of lung cancer was more common in women who carried the mutation.
Among lung cancer tumors seen in T790M germline mutation carriers, 73% had a second activating EGFR gene mutation. The OR that carriers of the T790M germline mutation who smoke will develop lung cancer vs. never-smoker carriers was 0.31. Compared with the general population, the incidence of never-smokers with lung cancer who carry this mutation is disproportionate compared with the general lung cancer population.
Gazdar said the study’s findings about never-smokers and women were entirely unexpected, but this mutation is rare in the general population and easily identified.
“Only people suspected of having the mutation and their family members need to be tested for the mutation. It’s rare, but you’re still faced with families like this. As people get more attuned to recognizing lung cancer patients with this mutation, we’re going to be identifying more family members with this inherited risk, and we will have to develop guidelines on how to manage them.”
Disclosure: The researchers report no relevant financial disclosures.