Why 20 percent of lung cancer patients have never smoked a cigarette

Medical experts are challenging the common misconception that lung cancer is a disease exclusive to smokers.

Dr Jeremy London, a board-certified cardiothoracic surgeon with over two decades of experience, took to Instagram on Friday to clarify that a lack of tobacco use does not guarantee immunity.

In a detailed briefing, he revealed that a significant 15 to 20 percent of diagnoses occur in individuals who have never touched a cigarette.

Beyond the cigarette

Dr London identified several critical factors that contribute to this statistic. Passive smoking remains a primary concern; living or working in smoke-filled environments can raise a person's risk by up to 30 percent.

“The short answer is yes. Now, obviously the lion's share of patients are smokers, but 15 to 20 percent of lung cancers occur in individuals that have never smoked,” the surgeon explained.

Environmental and genetic triggers

The risk is further compounded by external and internal factors:

Environmental pollutants: High urban pollution and exposure to substances like radon, asbestos, and silica are major contributors.

Genetic history: Having a first-degree relative with the disease increases personal risk.

Underlying conditions: Pre-existing issues such as emphysema or COPD heighten vulnerability.

Dr London stresses that awareness is vital for early detection. “In addition, genetic factors, a first-degree relative with lung cancer, or if you yourself have emphysema or COPD, that also increases your risk,” he noted.

He advises anyone with these risk factors to consult a professional regarding early screening, regardless of their smoking history.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.