Bengaluru: While the link between tobacco and lung cancer is well-established, doctors are now raising alarms about a growing burden of tobacco-related cancers affecting multiple organs, including the stomach, liver, kidneys, pancreas, head and neck, and blood. According to Dr Naveen T, director of Kidwai Memorial Institute of Oncology (KMIO), tobacco accounts for nearly 62% of cancers among Indian men and 33.2% among women. In Karnataka, about 40.4% of all newly diagnosed cancers are tobacco-related, while at KMIO, 50.3% of all cancers treated are linked to tobacco use. Among men, nearly 59% of cancers are tobacco-related, while among women the figure is 42%.
Dr Naveen highlighted that Bengaluru has witnessed a steady rise in oral cancers over the years. “Among men, tongue cancer has shown an average annual percentage increase (AAPC) of 1.8%, while mouth cancer has increased by 2.2% per year from 1982 to 2025, indicating a growing burden of oral cancers, largely attributable to tobacco use. Among women, apart from lung cancer, most tobacco-related cancer sites have shown a relatively stable trend over the years.”
Data from KMIO also revealed a rise in the proportion of several tobacco-related cancers between 2015 and 2025. Among men, tongue cancer increased from 10.7% to 13%, mouth cancer from 11.5% to 16.3%, and liver cancer from 4.1% to 8.9%. Among women, tongue cancer rose from 2.2% to 3.3%, mouth cancer from 15.9% to 20%, and liver cancer from 1.3% to 3.4%.
Doctors emphasized that tobacco remains the leading preventable cause of death globally, accounting for nearly 7 million deaths annually. Dr Radheshyam Naik, founder and medical director of Sammprada Hospital, explained, “About 35-40% of all cancers are related to tobacco in one form or the other. This includes both smoking tobacco and smokeless tobacco products such as chewing tobacco, snuff, and gutka. In some cancers, tobacco is the sole cause, while in others it acts as a co-factor along with alcohol, pollution, poor diet or other risk factors.”
Dr Naik elaborated on how tobacco affects multiple organs: “As smoke passes through the mouth, throat, food pipe and stomach, it increases the risk of cancers in these organs. Harmful chemicals are also absorbed into the bloodstream and can reach the liver, kidneys, pancreas, and bladder, contributing to cancers there. In some cases, tobacco-related toxins can even affect the bone marrow, increasing the risk of blood disorders and leukaemia.”
Doctors also cautioned against the dangers of second-hand smoke. Dr Ajay Handa, senior consultant at Sakra World Hospital, said, “Exposure to second-hand smoke for a long time contributes to deaths from heart disease, stroke, lung cancer and COPD. Tobacco use and exposure to tobacco smoke during pregnancy increase the risk of foetal death, miscarriage, and stillbirth. Children living with smokers are at greater risk of bronchitis, asthma, pneumonia, and respiratory infections.”
While the overall burden remains highest among people above 54 years of age, oncologists are increasingly seeing tobacco-related cancers in younger adults. Dr Naik noted, “Most tobacco-related cancers typically develop after 15 to 20 years of tobacco use. However, we are increasingly seeing younger patients, including those in their 20s and 30s, as tobacco use begins at an earlier age. Cases among women are also on the rise. Early exposure, including passive smoking, can significantly increase the risk of developing cancer at a younger age.”
Additionally, doctors observed that in a bid to quit cigarettes, many are now turning to vaping or e-cigarettes, which is giving rise to e-cigarette or vaping use-associated lung injury (EVALI). Dr Madhavi Nair, consultant surgical oncologist at Manipal Hospitals, warned, “As tobacco-related cancers are increasing, we are also seeing a rise in EVALI. Youngsters think that vaping is safer than smoking cigarettes, but vaping also introduces a lot of nicotine into the body, leading to nicotine addiction. We do not even know the long-term side-effects yet. While e-cigarettes probably have fewer chemicals, they are as dangerous as cigarettes.”
