Tobacco may be responsible for nearly three out of four mouth cancers among women in India, while it contributes to more than half of such cancers among men, according to a new study that estimated the national and state-wise burden of head and neck cancers linked to tobacco use.
Published in the latest edition of the Indian Journal of Medical Research (IJMR), the study, Head and neck cancer burden attributable to tobacco use in India: National and region-wise estimates, found that tobacco use in any form accounted for an estimated 73.4% of mouth cancers among women and 57.3% among men.
It also accounted for 65% of pharyngeal cancers and 49% of laryngeal cancers among men. Among women, the corresponding estimates were 31% for pharyngeal cancers and 32% for laryngeal cancers.
Researchers had analysed records of 11,285 people diagnosed with head and neck cancers and 7,154 individuals with non-cancerous conditions who attended the centre between 2019 and 2024.
The findings underline the scale of a largely preventable cancer burden and the need to strengthen tobacco-control measures, particularly against smokeless tobacco products that remain widely used in several parts of the country.
Researchers estimated the population attributable fraction (PAF), which indicates the proportion of cases that could potentially be prevented if exposure to a risk factor were eliminated. The estimates do not mean that tobacco caused every individual cancer included in these categories, but they show how heavily the overall disease burden is linked to its use.
The study found a particularly strong contribution from smokeless tobacco to cancers of the lip, tongue and mouth.
Among men, smokeless tobacco accounted for an estimated 62% of lip cancers, 30.7% of tongue cancers and 57.3% of mouth cancers. Among women, the corresponding proportions were 68.8% for lip cancer, 22% for tongue cancer and 68% for mouth cancer.
Smoking tobacco, meanwhile, was strongly associated with cancers of the pharynx and larynx. Among men, the estimated contribution of smoking was 40.2% for oropharyngeal cancer, 45.7% for hypopharyngeal cancer and 38.4% for laryngeal cancer. Among women, smoking accounted for an estimated 41% of oropharyngeal and 34% of hypopharyngeal cancers.
The findings highlight how different forms of tobacco contribute to cancers at different sites in the head and neck. Chewing tobacco and related products expose the oral cavity directly to carcinogens, while smoking is an important risk factor for cancers of the throat and voice box.
The burden varied considerably across states and regions. Among men, the estimated contribution of smokeless tobacco to mouth and lip cancers exceeded 70% in several states in central, eastern and northeastern India. These included Uttar Pradesh, Chhattisgarh, Jharkhand, Odisha, Bihar and several northeastern states.
Among women, the contribution of smokeless tobacco to lip cancer exceeded 80% in Chhattisgarh, Odisha and several northeastern states. Its contribution to mouth cancer was also above 70% in a number of these states.
Smoking-related cancers of the pharynx and larynx were particularly prominent in several northern and northeastern states. The researchers said these variations reflect differences in tobacco consumption patterns and the types of products used across regions.
The study was conducted at the Regional Cancer Centre (RCC), Thiruvananthapuram, Kerala, between January and September 2025.
The cancer patients were compared with controls matched for age and gender. Researchers assessed the association of smoking and smokeless tobacco use with different cancer sites, adjusting for factors including age, gender and alcohol use. They then combined the estimated risks with state-wise tobacco-use prevalence data from the Global Adult Tobacco Survey-2 to calculate national and regional population attributable fractions.
The researchers said this was the first Indian study to estimate the population attributable fraction of different head and neck cancers specifically linked to smoked and smokeless tobacco.
They also acknowledged limitations. The risk estimates were derived from a hospital-based study in Kerala and applied to other states because comparable state-specific risk data were not available. Differences in tobacco products and consumption habits across regions may therefore not have been fully captured.
Head and neck cancers include cancers of the mouth, tongue, pharynx, larynx and other sites. India has a particularly high burden of oral cavity cancers compared with global estimates, making tobacco prevention a key public-health priority.
The researchers have called for stronger tobacco-cessation services, routine screening for tobacco use by healthcare providers and better access to evidence-based support to quit.
They also emphasised the need for region-specific policies and stronger implementation of the National Tobacco Control Programme.
The study was authored by Dr Guruprasad Vinod and Dr Preethi Sara George from the Division of Cancer Epidemiology and Biostatistics; Dr Rejnish R. Kumar, Dr Melbin Sabu and Dr Aleyamma Mathew from the Division of Cancer Epidemiology and Biostatistics; Dr R. Jayakrishnan from the Division of Community Oncology; and Dr Shaji Thomas from the Division of Surgical Services, all at the Regional Cancer Centre, Thiruvananthapuram, Kerala.
Dr Guruprasad Vinod is also affiliated with Manipal Academy of Higher Education, Karnataka.
