Why Do Some People Who Have Never Smoked Get Lung Cancer?

Nick Baker, Web Experience and Content Manager

As tobacco use has declined in recent years, we have seen a new demographic of lung cancer patients emerge. Lung cancer in individuals who have never smoked (LCINS) is becoming more common. These people are often younger women with no history of tobacco exposure.

Researchers are working to understand the needs of this growing population by identifying other risk factors for lung cancer, such as family history and environmental exposures. They are also studying the molecular underpinnings of this disease to develop targeted approaches for early detection and treatment.

As part of LUNGevity’s International Lung Cancer Survivorship Conference last September, we hosted an educational session about lung cancer in individuals who have never smoked with Jaclyn LoPiccolo, MD, PhD, of the Dana-Farber Cancer Institute.

The virtual International Lung Cancer Survivorship Conference is the place to learn about state-of-the-art treatments and cutting-edge developments in lung cancer from experts around the world.

You can register now for this year’s conference on September 26-27, 2025.

We’ve Known Anyone Can Get Lung Cancer: 00:00–4:30

During her introduction, Dr. LoPiccolo highlights that we have known for a while that people can develop lung cancer with no smoking history. She then briefly talks about the usage of “smoker” and “never-smoker” and the stigma that comes with these terms. Importantly, she clarifies language, such as “remote smoking,” “light smoking,” and “very light smoking,” to help people understand how to accurately describe their situation.

Defining LCINS: Lung Cancer in Those Who Have Never Smoked: 4:31–21:18

Dr. LoPiccolo shares research data of lung cancer in those who have never smoked (LCINS) and highlights:

Approximately 66% of LCINS cases occur in women. Making women who have not smoked more than twice as likely to develop lung cancer than men who have not smoked
More common among women in Asia than other regions
Some association with younger age

To explain what LCINS is, Dr. LoPiccolo gives a scientific breakdown and a look under the microscope at how LCINS compares to tobacco-related lung cancer—make sure to tune in at 8:10.

What Causes Lung Cancer in People Who Have Never Smoked? 21:19–36:01

Dr. LoPiccolo goes one-by-one, discussing the different environmental and genetic risk factors for LCINS:

Radon exposure
Household pollution
Prior chest radiation
Occupational carcinogens
Secondhand smoke
Air pollution
Common variants (SNPs)
Rare variants
Familial lung cancer syndromes
Female gender

Building off the discussion of risk factors, Dr. LoPiccolo goes into her primary area of research—the relationship between inherited genetics (the genes people inherit at birth) and lung cancer.

Getting back to the big question—what causes lung cancer in people who have no smoking history? Researchers are still working to answer this question, but Dr. LoPiccolo shares the current thinking—it likely involves interactions between an inherited genetic risk and environmental exposures such as air pollution.

How Do We Treat and Detect LCINS Earlier? 36:02–43:00

An often-used approach to treating LCINS is genotype-directed treatment, which involves testing blood and tissue to look for biomarkers that can inform the treatment.

Current lung cancer screening guidelines only recommend screening for people with a history of significant tobacco exposure. As one of the leading LCINS researchers, Dr. LoPiccolo discusses ways to improve screening guidelines to detect lung cancer in people who have never smoked. One suggestion involves focusing on people at high-risk for lung cancer based on the environmental and genetic factors previously talked about:

A family history of lung cancer
Exposure to environmental risks while at work
Living in a high-pollution area
Having undergone prior chest radiation

Dr. LoPiccolo closes by inviting people with lung cancer to complete an interest form for ongoing studies looking into the genetic and hereditary risk of lung cancer.

The 2025 International Lung Cancer Survivorship Conference features an agenda of world-renowned researchers and clinicians sharing the latest breakthroughs in lung cancer care, treatment, and survivorship. Registration is free and now open.