Lung cancer was almost synonymous with smoking for decades. However, in the clinics of today, doctors are increasingly diagnosing lung cancer in people who have never lit a cigarette. Many are women, younger adults, and people who do not have any apparent lifestyle risk factors. This is one of the largest changes that respiratory physicians and oncologists are seeing. Dr Harshil Alwani, consultant, Pulmonology, Narayana Hospital, Jaipur, explains the risk to non-smokers.
Primary cause of lung cancer
Dr Harshil Alwani said, “Although smoking is still the primary cause of lung cancer worldwide, a large percentage of lung cancer cases are now in never-smokers.” Indeed, if lung cancer in never-smokers was a disease on its own, it would be one of the top cancer killers in the world. This is an indication that the disease is more complicated than people think.
Other causes of lung cancer
According to Dr Harshil Alwani, non-smokers who develop lung cancer are biologically different. Lung cancers caused by these tumours are more likely to have certain genetic changes, including mutations in the EGFR gene or ALK rearrangements, than smoking-related lung cancers. These are not inherited mutations, but mutations that occur over time in the cells of the lungs. It is crucial to recognise these changes, as many patients may be able to receive highly targeted drugs rather than standard chemotherapy.
What triggers these cancers?
There is no right or wrong answer. Dr Harshil Alwani highlighted that exposure to air pollution over a long period of time is now associated with lung cancer, especially in urban areas with high population density. Fine particulate matter (PM2.5) can lead to chronic inflammation in the lungs and can stimulate the growth of cells that already contain cancer-causing mutations. Other risk factors include indoor air pollution from biomass fuel for cooking, exposure to substances like asbestos, silica, or diesel exhaust at work, and long-term exposure to radon gas in some buildings.
Symptoms of lung cancer
One of the other things that patients are often surprised to learn is that lung cancer can start with non-obvious symptoms. A cough that doesn’t go away is not always the first symptom. Some patients may have unexplained tiredness, pain in the shoulder, frequent attacks of pneumonia in the same area of the lung, or shortness of breath that slowly gets worse despite treatment for common respiratory conditions. The symptoms are frequently misdiagnosed as allergies, infections or ageing.
Treatment of lung cancer
Dr Harshil Alwani highlighted that the treatment has undergone a dramatic transformation. Molecular testing is now an essential component of diagnosis as it can help identify patients who may benefit from targeted therapies or immunotherapy, which can be used to treat the biology of the tumour, rather than a one-size-fits-all approach.
The single most important thing doctors want to change is the misconception that “never smoking” equals “no risk” of lung cancer. If symptoms of the respiratory system do not settle or keep coming back even after proper treatment, they should be carefully evaluated and not taken for granted. The biggest barrier to successful treatment in lung cancer is the delay in considering the diagnosis, not the absence of smoking.
About Dr Harshil Alwani
Dr Harshil Alwani is a highly skilled Pulmonologist with expertise in diagnosing and managing complex respiratory disorders.
