Lung cancer is undergoing a dramatic shift in India. While smoking continues to remain the single biggest risk factor, oncologists are witnessing a steady rise in lung cancer among younger adults, women and even people who have never smoked, highlighting the growing impact of pollution, lifestyle changes and environmental factors, on one's lungs.
Ahead of World Lung Cancer Day, Dr. Radheshyam Naik, Senior Consultant Medical Oncologist and Head of the Bone Marrow Transplant (BMT) Unit, Sammprada Hospital, Bengaluru, said that the outdated belief that only smokers develop lung cancer is preventing many people from recognizing symptoms early and seeking timely medical care.
"Smoking remains the leading cause of lung cancer, but it is no longer the whole story," said Dr. Naik. "We are increasingly seeing lung cancer in people who have never smoked, particularly women and younger adults. Passive smoking, traffic-related air pollution, indoor pollution from biomass fuels and exposure to naturally occurring radon gas are all contributing to this changing disease pattern."
According to Dr. Naik, approximately 5–7% of lung cancer cases are linked to passive smoking, while around 10% are associated with traffic-related air pollution. Another 10–15% of non-smoking-related lung cancers are attributed to radon gas exposure, with indoor air pollution from traditional cooking fuels also contributing to the disease burden.
The profile of lung cancer itself has changed significantly over the past two decades. Earlier, India saw a higher proportion of aggressive smoking-related cancers such as squamous cell carcinoma and small-cell lung cancer, largely associated with heavy smoking and beedi consumption. "Today, nearly 80% of lung cancers that we diagnose are adenocarcinomas, a pattern that now closely resembles Western countries," Dr. Naik explained. "This reflects changing smoking habits, greater use of filtered cigarettes and broader lifestyle changes."
Doctors are also observing an increasing number of younger patients and women being diagnosed with lung cancer. While the reasons require further scientific study, Dr. Naik said the trend is likely being driven by multiple factors, including rising tobacco use among women and adolescents, unhealthy diets, obesity, physical inactivity, alcohol consumption and worsening environmental pollution.
One of the biggest breakthroughs in lung cancer care has come from artificial intelligence, which is helping doctors diagnose the disease earlier and with greater precision.
AI is proving valuable in pathology by helping specialists distinguish cancer from benign conditions and accurately identify the exact subtype of lung cancer, which is a critical step because treatment varies considerably depending on the tumour type.
Artificial intelligence is also enhancing radiology by analysing CT scans more accurately, helping doctors determine whether suspicious lung nodules are likely to be cancerous and identifying patients who require biopsies or surgery.
"AI is becoming an invaluable decision-support tool. It improves diagnostic accuracy, reduces uncertainty and helps us begin the right treatment much earlier," Dr. Naik said.
Perhaps the most significant transformation in lung cancer care has come from molecular profiling and biomarker testing, which now form the cornerstone of modern treatment. Rather than treating all lung cancers alike, doctors now prefer to classify tumours according to their genetic mutations and immune characteristics. This allows patients to receive highly personalized therapies, including targeted drugs and immunotherapy.
"Molecular testing and biomarker testing have become the foundation of lung cancer treatment today. They tell us which patients are likely to benefit from targeted therapies and who will respond to immunotherapy. Without these tests, it is difficult to offer the most effective treatment," Dr. Naik said.
He added that these advances are delivering meaningful improvements in survival not only for patients with advanced disease but also for those diagnosed at earlier stages, where targeted therapies and immunotherapy are increasingly being used alongside surgery and radiation.
While prevention through tobacco control remains the most effective strategy against lung cancer, Dr. Naik said the future has never looked more promising for patients.
"The first step is still prevention, which means never start smoking, and if you smoke, quit as early as possible. But for those who develop lung cancer, the outlook is changing for the better. Research in genomics, immunotherapy and targeted medicines is advancing at extraordinary speed. Over the next five to ten years, we expect many patients to live much longer than before, and for some categories of lung cancer, we expect to achieve complete cure."
As India marks World Lung Cancer Day, experts emphasize that awareness must move beyond tobacco alone. Recognizing that lung cancer can affect non-smokers, women and younger adults, and ensuring timely diagnosis through advanced technologies and precision medicine, will be critical to reducing the country's growing burden of the disease, Dr. Naik said.
