While smoking remains the leading cause of lung cancer, a shifting demographic in East Asia, including South Korea, is causing concern: more than half of newly diagnosed lung cancer patients are now non-smokers. This suggests that relying solely on smoking history is no longer sufficient to predict or prevent the disease.
To address this, a joint research team from the Samsung Medical Center (Department of Thoracic Surgery) and Asan Medical Center (Department of Pulmonology) conducted a comprehensive analysis of risk factors specifically affecting non-smokers in Korea.
The Impact of Chronic Lung Disease: A 7.3-Fold Risk
The study compared 3,000 non-smokers diagnosed with non-small cell lung cancer (NSCLC) between 2016 and 2020 against a control group of 3,000 healthy individuals. The findings revealed that a history of chronic lung disease is the most significant predictor of cancer in non-smokers.
General Lung Disease: Non-smokers with a history of conditions such as pulmonary tuberculosis or chronic obstructive pulmonary disease (COPD) were 2.9 times more likely to develop lung cancer.
The COPD Factor: Among those specifically suffering from COPD, the risk plummeted to a staggering 7.3 times higher than the healthy control group.
The researchers explained that chronic inflammatory responses caused by these underlying diseases likely create an environment conducive to the development of cancerous cells.
Family History and Socio-Environmental Factors
The study also identified several other key variables that increase risk:
Genetics: Having a first-degree relative with lung cancer increases the risk by 23%. If a sibling has a history of the disease, that risk jumps to 54%.
Socio-Economics: Unemployed individuals faced a 32% higher risk.
Geography: Residents living outside the metropolitan Seoul area were 2.81 times more likely to develop lung cancer. This disparity is attributed to differences in industrial environments and varying levels of access to medical care.
Moving Beyond Smoker-Centered Screening
Professor Ji Won-jun of Asan Medical Center’s Pulmonology Department noted, "Lung cancer in non-smokers arises from a complex interplay of underlying diseases, family history, and environmental factors." She emphasized the urgent need for new screening protocols that can identify high-risk non-smokers.
Professor Kim Hong-kwan of Samsung Medical Center added, "Non-smokers often neglect their lung health because they feel safe from the traditional risks. However, if you have a history of chronic lung disease or a family history of cancer, regular check-ups are essential."
The findings of this study were recently published in Chest, a leading international journal in respiratory medicine.
