A single misspelled letter in one gene can raise a person’s lung cancer risk by 25 times, and for people who never smoked a cigarette, that risk jumps to more than 60 times normal.
Story Snapshot
- Researchers from Dana-Farber Cancer Institute and the 23andMe Research Institute found an inherited gene mutation called EGFR T790M tied to sharply higher lung cancer risk.
- Carriers overall face a 25-fold higher lung cancer risk, but never-smokers with the mutation face a risk more than 60 times higher than noncarriers.
- The study, published in the journal Science, found only 641 carriers among more than 10 million participants tested.
- Even smokers who carry the mutation showed about 10 times the lung cancer risk of noncarriers, suggesting the gene matters no matter someone’s smoking history.
A Rare Mutation With an Outsized Effect
Scientists have known for years that lung cancer sometimes strikes people who never touched a cigarette. The new study gives one of the clearest answers yet as to why. Dana-Farber and 23andMe researchers identified EGFR T790M, an inherited gene mutation, as a major driver of risk in a subset of these cases. The finding does not explain every nonsmoker diagnosis, but it hands doctors a concrete genetic marker to watch for.
The scale of the research sets it apart from earlier studies on this topic. Investigators combed through genetic and health data from more than 10 million people who had taken 23andMe tests, then cross-checked outcomes against more than 3.3 million participants who reported whether they had been diagnosed with lung cancer. Out of that massive pool, only 641 people carried the T790M mutation, underscoring just how rare this inherited risk factor is.
Despite the small number of carriers, the association held up strongly across the group. Dana-Farber’s own announcement described carriers as facing a 25-fold increased risk of lung cancer compared to noncarriers, a figure Time also reported when covering the study’s release. That number alone would make T790M one of the most powerful inherited cancer risk mutations identified in recent years.
Why Never-Smokers Face the Steepest Climb
The risk grows even larger when researchers looked only at people who never smoked. Dana-Farber reported that never-smoking carriers were more than 60 times as likely to develop lung cancer as people without the mutation, and Time’s coverage repeated that same 60-fold figure. For a disease so often blamed entirely on tobacco, that statistic forces a rethink of who counts as high risk.
Smokers who carried the mutation were not spared either. Dana-Farber’s release found they faced roughly 10 times the lung cancer risk of noncarriers, even though tobacco already elevates their baseline risk substantially. That detail matters because it shows the mutation adds danger on top of smoking, rather than only mattering in its absence.
This is not the first time doctors have linked inherited EGFR changes to lung cancer that runs in families. Earlier peer-reviewed research already showed that never-smokers carrying germline EGFR T790M mutations develop lung cancer more often than smokers who lack the mutation. A 2023 review of familial lung cancer cases found that 50 of 91 confirmed or obligate carriers across 39 family lines eventually developed the disease, with many diagnosed before age 60. The new study builds on that foundation with a dataset orders of magnitude larger.
What Comes Next for Patients and Families
The rarity of the mutation means most lung cancer cases still trace back to smoking, air pollution, or other known causes. But for families with a history of lung cancer among nonsmokers, this discovery offers a concrete reason to consider genetic testing. Identifying carriers early could let doctors monitor lung health more closely long before symptoms appear, potentially catching tumors at a more treatable stage.
Researchers have not yet published every technical detail behind the 25-fold and 60-fold figures, including how the numbers might shift across different age groups or ancestries. That level of detail typically follows in the full published study and later analyses. What is already clear from the released findings is that a single inherited gene mutation can dramatically reshape a person’s lung cancer odds, regardless of whether they ever picked up a cigarette.
Carriers of the EGFR T790M mutation have a 25-fold higher risk of lung cancer regardless of smoking, and among nonsmokers the risk jumps to 60-fold: a signal strong enough that the data, drawn from 23andMe’s large genetic repository, now allows population-level risk estimates for…
— NewsWhat (@NewsWhatHQ) September 17, 2026
For families who have watched loved ones develop lung cancer without any history of smoking, this research offers something rare in medicine: a specific, testable explanation. As more studies confirm and refine these numbers, genetic screening for EGFR T790M could become a standard part of assessing lung cancer risk in high-risk families nationwide.
Sources:
time.com, dana-farber.org, sharjah24.ae, pmc.ncbi.nlm.nih.gov
