"You Can't Feel Safe Just Because You Don't Smoke"...Key Risk Factors for Lung Cancer in Never-Smokers Identified

Joint Research Team from Samsung Medical Center and Asan Medical Center in Seoul
Up to Sevenfold Higher Risk of Onset with Chronic Lung Disease
Family History, Region of Residence, and Unemployment Also Have an Impact

As a significant number of lung cancer cases are occurring in people with no history of smoking, a new study has found that there are limitations to the current smoking-history-centered perception of lung cancer.

A Korean research team analyzed 6,000 never-smokers and found that those with chronic lung disease had up to more than a sevenfold higher risk of developing lung cancer. Family history and socioeconomic factors were also identified as elements that increase the risk of onset.

The research team at Samsung Medical Center that reported findings showing limitations in lung cancer recognition centered on smoking history.

Samsung Medical Center announced on the 11th that a joint research team led by Professors Kim Honggwan and Lee Jeonghee of the Department of Thoracic and Esophageal Surgery at Samsung Medical Center, and Professor Ji Wonjun of the Division of Pulmonology at Asan Medical Center in Seoul, identified the major risk factors affecting lung cancer development in Korean never-smokers and published the findings in the latest issue of Chest, a leading journal in the respiratory field.

The research team conducted a comparative analysis of 3,000 never-smokers diagnosed with non-small cell lung cancer at Korean hospitals between 2016 and 2020 and a control group of 3,000 individuals without lung disease. The subjects were matched one-to-one by age, sex, and other factors.

The analysis showed that the strongest risk factor for lung cancer in never-smokers was chronic lung disease. Even without a history of smoking, individuals with a history of chronic obstructive pulmonary disease or pulmonary tuberculosis had a 2.9-fold higher risk of developing lung cancer than the control group. In particular, patients with chronic obstructive pulmonary disease had a risk that increased up to 7.2-fold. The researchers suggested that persistent chronic inflammation in the lungs may have influenced cancer development.

Family history also emerged as a significant factor. When there was a lung cancer patient among first-degree relatives, the risk of onset was 1.2 times higher. When a sibling had a history of lung cancer, the risk increased up to 1.5 times.

Socioeconomic factors likewise proved to be variables that cannot be ignored. Residents outside the Seoul metropolitan area had a 2.8-fold higher risk of lung cancer compared to residents within the metropolitan area. The research team noted that differences in regional industrial environmental exposure and disparities in access to medical care may have acted in combination. Being unemployed was also associated with a 1.3-fold increase in lung cancer risk.

The researchers explained that these findings show that lung cancer in never-smokers does not arise from a single cause, but rather from the combined effects of underlying diseases, genetic factors, and the social environment. They pointed out the need for strategies to identify high-risk groups among never-smokers that go beyond the existing criteria of assessing lung cancer risk based solely on smoking status.

The research team emphasized that even if a person does not smoke, regular screening and management are important if they have chronic lung disease or a family history of lung cancer.

Professor Ji said, "This study suggests that lung cancer in never-smokers arises not from a single factor, but from a complex background that includes underlying diseases, family history, and social and environmental factors," adding, "We need new prevention and treatment strategies that can identify high-risk groups among never-smokers, beyond the existing screening system focused on smokers."

Professor Kim said, "Because of the perception that 'lung cancer equals smoking,' never-smokers tend to be relatively negligent about their lung health," and added, "Even if you do not smoke, if you have chronic lung disease or a family history of lung cancer, it is important to make efforts to detect lung cancer early through regular checkups and meticulous management."

This content was produced with the assistance of AI translation services.