Lung Cancer In Non-Smokers

Lung cancer is one of the most frequent causes of cancer-related deaths globally. Lung cancer is a fatal disease if not treated timely. Lung malignancies account for 11–12% of all cancer cases worldwide.

About 70,000 new lung cancer cases are detected in India each year, making up about 6-7% of all cancer cases. Lung cancer is significantly increased by tobacco use. As stress levels and social engagement have increased, smoking has grown more common in rural areas of India and among young people everywhere.

Smoking is widely acknowledged to be the primary risk factor for developing lung cancer throughout the course of one's lifetime. Smoking habit is steadily declining in the western world along with a little drop in lung cancer incidences due to growing awareness of the negative effects of smoking and its link to cancer.

However, non-smokers are also developing lung cancer at a higher rate. The negative effects of second-hand or passive smoking are not widely known in society. The public has to be made more aware of passive smoking's role as a key risk factor for lung cancer.


More than 50% of women and about 15% of men with lung cancer are not smokers. The main causes of cancer in non-smokers are environmental exposures to asbestos, chromium, arsenic, and pollutants, as well as passive/second-hand smoking.

According to several studies, second-hand smoke exposure causes 15–35% of lung cancer in nonsmokers. Other family members are more likely to get malignancies, including lung cancer, as a result of indirect cigarette smoke exposure. As people age, the risk factor increases.

Asthma and other respiratory disorders affect children in their early years, but long-term exposure to passive smoking raises their risk of developing lung cancer in later life.

Nonsmokers also have some genetic predispositions for developing lung cancer. In families with high incidences of lung cancer in non-smokers, certain germ line mutations have been discovered. The risk of any cancer among first-degree relatives is increased by 25%. This malignancy is linked to several EGFR receptor mutations. The discovery of this mutation prompted the creation of a tailored therapy for those who carry it.


Smokers and non-smokers both exhibit similar lung cancer symptoms and indicators. These include symptoms including coughing, dyspnea, weight loss, and loss of appetite and are frequently nonspecific. Chest pain and blood in the cough or sputum are more specific symptoms that can also be present in other conditions.

Although nonsmokers do not have a better prognosis, they do not respond to routine treatment any better than smokers do.As mortality rates mostly depend on the stage of cancer, they do not differ from the smoker group.There are many genetic mutations associated with non-smoker adenocarcinoma lung, which can be targeted with novel treatment approaches called as targeted therapies or immunotherapy. These drugs may help nonsmokers respond more quickly and live longer than smokers.

There are no screening guidelines for lung cancer in non-smokers; however it is advisable to speak with an oncologist if there is a history of the disease in your family or if any symptoms are bothersome. It has been demonstrated that earlier diagnoses lead to improved outcomes and cure rates.

Early stages of the treatment may involve surgery or radiotherapy, whereas later stages may involve radiotherapy and/or chemotherapy. There are now precision radiation treatments that can target a specific cancer lesion with little or no side effects.

Similarly, more recent systemic medicines with less side effects, such as targeted and immunotherapies, offer greater results. In order to save lives, it is essential to take additional precautions for respiratory health, thus people should give up smoking and limit their exposure to secondhand smoke.

Dr. Gyanendra Agarwal
Department of Internal Medicine, Respiratory & Critical Care Medicine
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