mokeless Tobacco Drives a Major Share of Mouth Cancers in India

Smokeless tobacco accounts for an estimated 68% of mouth cancers among women and 57.3% among men in India, according to a new study published in the Indian Journal of Medical Research. The findings expose the heavy burden associated with chewing tobacco and other smokeless products, while highlighting differences in tobacco-related cancer risks across genders and states.

The study, titled Head and Neck Cancer Burden Attributable to Tobacco Use in India: National and Region-wise Estimates, examined the contribution of tobacco to several types of head and neck cancer. Researchers estimated that tobacco in any form was responsible for at least 73.4% of mouth cancers among women.

The findings point to a major public health concern. While smoking remains strongly associated with cancers affecting parts of the throat and voice box, smokeless tobacco emerged as a leading risk factor for cancers of the mouth and lips.

Study Examines More Than 11,000 Cancer Patients

Researchers analysed records from 11,285 patients diagnosed with head and neck cancers and 7,154 people with non-cancerous conditions. The participants visited the Regional Cancer Centre in Thiruvananthapuram, Kerala, between 2019 and 2024.

The team assessed tobacco-related risks by sex and cancer site, then used the findings to estimate the national and state-level burden attributable to tobacco exposure.

Among men, smokeless tobacco was estimated to account for 61.8% of lip cancers, 30.7% of tongue cancers and 57.3% of mouth cancers.

Smoking showed a different pattern. It accounted for an estimated 40.2% of cancers affecting the base of the tongue, tonsils and oropharynx, a region that includes parts of the throat. The researchers also attributed 45.7% of hypopharyngeal cancers and 38.4% of laryngeal cancers among men to smoking.

The differences reflect how tobacco products expose tissues to cancer-causing substances. Smokeless products remain in direct contact with the lining of the mouth, potentially exposing oral tissues to carcinogens for prolonged periods.

The patient records also showed a marked difference in tobacco use between men with mouth cancer and those in the comparison group. Some 55.3% of men diagnosed with mouth cancer used smokeless tobacco, compared with 17.5% of men without cancer.

Among men with hypopharyngeal cancer, 85% reported smoking.

Women Face High Risks From Chewing Tobacco

The findings among women were particularly striking. Smokeless tobacco accounted for an estimated 68.8% of lip cancers and 68% of mouth cancers.

Smoking was linked to 41% of oropharyngeal cancers and 34% of hypopharyngeal cancers among women.

The researchers also found a strong association between smokeless tobacco use and mouth cancer. Women who used these products had 17.6 times the odds of developing mouth cancer compared with non-users. Among men, the corresponding odds were 5.5 times higher.

These figures are odds estimates, not direct measurements of an individual's lifetime risk. They nevertheless indicate a strong relationship between smokeless tobacco consumption and mouth cancer in the study population.

The results also challenge the assumption that tobacco-related cancer prevention should focus primarily on smoking. Chewing tobacco and similar products require sustained attention, particularly in communities where their use is widespread.

Tobacco-Related Cancer Risks Vary Across States

The estimated burden differed sharply by region, reflecting variations in tobacco consumption and the products people use.

Among men, the estimated share of mouth cancers attributable to smokeless tobacco reached 71% in Jharkhand and 70.3% in Odisha. The figures were lower across several southern states: 50.2% in Karnataka, 35.1% in Tamil Nadu, 33.9% in Telangana, 25.6% in Andhra Pradesh and 25.1% in Kerala.

Among women, the estimated proportion exceeded 80% in Chhattisgarh, Odisha and several Northeastern states. Tripura recorded an estimated 90.4%.

However, the national and state estimates require careful interpretation. The researchers derived tobacco-related cancer risk estimates from hospital-based data collected in Kerala and applied them nationally because comparable state-specific risk estimates were unavailable.

They acknowledged that the study assumed tobacco-related cancer risks were uniform across the country. Differences in tobacco products, patterns of use and other local factors may affect the actual burden in individual states.

The findings should therefore be understood as estimates rather than precise counts of cancers caused by tobacco in each region.

Prevention and Tobacco Cessation Remain Priorities

The researchers called for stronger tobacco prevention and cessation services, with particular attention to populations facing a high estimated burden of tobacco-related cancers.

The study suggests that reducing tobacco exposure could prevent a substantial proportion of head and neck cancers. Effective public health efforts need to address both smoking and smokeless products, alongside measures that help users quit.

The regional differences also point to the need for better state-level data. More representative research could help authorities identify high-risk populations and direct prevention programmes where they are most needed.

The central finding is clear: smokeless tobacco is associated with a large share of mouth cancers in India, particularly among women. Expanding access to cessation support, improving awareness of the risks and strengthening regional prevention efforts could help reduce this burden.