Smokeless tobacco (ST) use is a leading, yet preventable, cause of oral cancer and related mortality worldwide. Although the health risks of ST are well established, its use continues to rise in many regions, particularly in low- and middle-income countries (LMICs). Addressing this growing public health challenge requires not only effective policy but also strong clinical engagement, including screening, counseling, and cessation support.
Global Burden of Smokeless Tobacco Use
Smokeless tobacco products are used by more than 360 million people across 140 countries, with approximately 77% of users living in LMICs, particularly in South and Southeast Asia. ST use is especially prevalent in Bangladesh, India, Pakistan, and Papua New Guinea, where it is deeply embedded in cultural practices and often perceived as more socially acceptable than cigarette smoking.
While cigarette smoking has declined in many parts of the world, ST use has increased in several high-burden countries. In India, for example, smokeless tobacco accounts for more than 60% of all tobacco use. ST use is also disproportionately common among populations with lower income and educational attainment, further compounding health inequities.
Smokeless Tobacco as a Carcinogen
Smokeless tobacco is classified as a Group 1 carcinogen by the International Agency for Research on Cancer, indicating sufficient evidence of carcinogenicity in humans. According to GLOBOCAN, there were 389,846 new cases of oral cancer globally in 2022, with incidence rising most sharply in regions where ST use is common.
Oral cancer is the most common cancer among men in South Asia, and India bears the largest global burden of both cases and deaths—reflecting its population size and high prevalence of ST use. An estimated 30% of oral cancer cases worldwide (more than 120,000 annually) are attributable to smokeless tobacco use, areca nut use, or both.
Diversity of Products, Diversity of Risk
Smokeless tobacco is not a single product but a broad category that includes chewing tobacco, snuff, gutka, khaini, betel quid with tobacco, snus, toombak, and iqmik, among others. Many of these products contain areca nut, which is itself a Group 1 carcinogen with addictive properties.
Cancer risk varies widely depending on:
- Product composition and nicotine concentration
- Manufacturing and storage practices
- Frequency and duration of use
- Co-exposures such as alcohol, smoking, or human papillomavirus (HPV)
In LMICs, many ST products are produced in informal or cottage industries, resulting in substantial variation in carcinogen levels. In India alone, the ST market includes more than 400 brands, making regulation and risk reduction especially challenging.
Disparities in Risk, Outcomes, and Survival
The proportion of oral cancers attributable to ST use differs markedly by region. In countries such as India and Sudan, more than 50% of oral cancers are linked to smokeless tobacco, compared with approximately 4% among men in the United States. These disparities reflect differences in product type, patterns of use, and access to early diagnosis and treatment.
Patients in LMICs experience worse prognosis and survival, largely because oral cancers are often detected at later stages and access to specialized care is limited. These inequities underscore the need for prevention-focused strategies and early intervention.
Rising Use Among Women and Youth
Unlike cigarette smoking, ST use is often viewed as socially acceptable, including among women in some regions. In Burkina Faso, for example, women who use tobacco do so almost exclusively in smokeless forms.
Youth uptake presents an additional concern. Data from the Global Youth Tobacco Survey show that between 2010 and 2019, the global prevalence of ST use among adolescents aged 12–16 years was 4.4%, with much higher rates in parts of the Western Pacific, including the Marshall Islands, Micronesia, Palau, and Papua New Guinea.
Manufacturers have increasingly targeted young people through:
- Flavorings and attractive packaging
- Manipulated nicotine content
- Products designed for discreet use in smoke-free settings
The Critical Role of Clinical Interventions
Despite its clear health risks, smokeless tobacco has historically received less research attention and fewer policy interventions than cigarette smoking, particularly in LMICs. However, clinical settings offer powerful opportunities for prevention.
According to the World Health Organization, there is strong evidence that behavioral interventions are effective in helping adults quit ST use. Evidence for pharmacologic interventions is emerging, with studies suggesting benefit from varenicline and nicotine replacement therapy, particularly when combined with counseling.
Health professionals—especially physicians and dentists—play a pivotal role by:
- Routinely asking patients about ST use
- Conducting oral examinations to identify precancerous lesions
- Using clinical encounters as “teachable moments” to encourage cessation
- Offering or referring patients to evidence-based cessation support
Although population-wide screening for oral cancer is not currently recommended, studies suggest potential benefit in high-risk groups, including ST and areca nut users.
Looking Ahead
Smokeless tobacco use and oral cancer represent a preventable global health crisis. Reducing the burden of disease will require stronger surveillance, better regulation, culturally informed public health strategies, and—critically—greater clinical awareness and action.
By recognizing ST use as a major risk factor, integrating cessation support into routine care, and prioritizing early detection in high-risk populations, health professionals can play a central role in preventing oral cancer and reducing global health inequities.
