Non-Smokers Account for 1/4th of all Cases of Lung Cancer in India: Doctor

BENGALURU / August 1, 2025: About 10-30% of all cases of lung cancer in India are found among people who have never smoked, with some Indian studies pegging this figure as high as 40%. The main reason for non-smokers getting lung cancer is exposure to carcinogens due to second-hand smoke, indoor air pollutants like burning of wood or charcoal, occupational exposure, and pre-existing lung disease. Some cases of lung cancer are also attributed to exposure to estrogens, a group of female sex hormones, which are known human carcinogens. This was said by Dr. Radheshyam Naik, Head – Medical Oncology, Hematology & Bone Marrow Transplantation at Sammprada Hospital, Bengaluru, on Lung Cancer Day.

Dr. Radheshyam Naik said: “Over the last three decades, there has been a steady rise in incidence of lung cancer in metro cities like Delhi, Bengaluru and Chennai, among both men and women. This signifies the role of smoking, rising indoor and outdoor air pollution, and increased detection due to more awareness among people about getting regular health check-ups.”

He added: “India is ranked 5^th globally in air pollution. Almost half of Indian adults face regular exposure to second-hand smoke at home, workplace or travel. Indoor air pollution accounts for 4-6% of the national burden of lung cancer in India. Almost 75% of Indian population relies on solid fuels for cooking, such as wood, cow dung cake or coal whose smoke can cause lung cancer. Even prolonged exposure to incense burning in closed areas significantly raises the risk of lung cancer. People who have been burning incense indoors for more than 40 years have been found to have four times higher risk of lung cancer than other non-smokers.”

Said Dr. Vinod K Ramani, Consultant – Preventive Oncology, Sammprada Hospital, Bengaluru: “In India, both smokers and non-smokers are likely to be diagnosed at an advanced stage of lung cancer. Symptoms such as cough, chest pain, and weight loss are common to both tuberculosis and lung cancer, irrespective of whether the person is smoker or non-smoker. Given the high prevalence of TB in India and the overlap of symptoms, a significant number of early lung cancer patients may get wrongly diagnosed with TB, leading to significant delay in diagnosis and treatment.”

Treatment of lung cancer include options like immunotherapy and targeted therapy as well as lung cancer vaccines which are given post-surgery for preventing recurrence of the disease. Family members of cancer patients should consider themselves high-risk of any cancer including lung cancer. They should be alert to symptoms such as long-standing cough, blood in the sputum and loss of weight. Non-smokers should undergo periodical screening tests for lung cancer. A whole-body MRI scan is recommended once every three years.”

Talking about what people can do to protect themselves from air pollution-related cancer risk, Dr. Vishwajeeth Pai, Consultant – Medical Oncology, Sammprada Hospital, Bengaluru, said: “Individuals should use a sanitary mask when exposed to outoor air that is poor in air quality. They should also avoid exposure to gases from fossil fuel combustion which are likely to contain carcinogenic substances. LPG should be used in cooking stoves rather than for driving vehicles. Also, indoor air should be tested for the radioactive radon gas emanating from the underground soil, which can pose a significant risk of lung cancer.”