Nearly 40% of cancers worldwide could be prevented.

On the occasion of World Cancer Day (February 4), a new analysis[1] A study coordinated by the World Health Organization (WHO) and the International Agency for Research on Cancer (IARC) estimates that nearly four out of ten cancers could be prevented globally. Based on international data and a systematic review of modifiable risk factors, the study highlights the central role of tobacco exposure, oncogenic infections, and alcohol consumption, as well as other determinants such as being overweight, physical inactivity, air pollution, and UV radiation. It also underscores significant disparities between genders and regions and reaffirms the crucial role of public prevention policies in sustainably reducing cancer incidence and associated costs.

The WHO and IARC have published a global analysis aimed at quantifying the proportion of cancers attributable to modifiable risk factors, in order to inform prevention priorities. The study is based on data covering 185 countries and 36 types of cancer, and examines 30 preventable causes, including tobacco, alcohol, high body mass index, physical inactivity, air pollution, ultraviolet radiation and, for the first time in this type of exercise, nine carcinogenic infections.[2].

7.1 million cancers linked to avoidable risk factors, mainly due to tobacco, infections and alcohol

It is estimated that approximately 7.1 million of the 18.7 million new cancer cases diagnosed worldwide in 2022 are attributable to modifiable risk factors, representing nearly 37% of global incidence. These data confirm that a substantial portion of the cancer burden results from avoidable exposures that can be directly addressed through prevention policies.

Tobacco appears to be the leading contributing factor, responsible for approximately 15.1% of all new cases, or nearly three million cancers. It remains the primary cause of lung cancer, but also contributes to many other cancers (particularly in the oral cavity, larynx, esophagus, bladder, and pancreas). Oncogenic infections are the second major factor, responsible for approximately 10.2% of cases, notably through human papillomavirus (cervical cancer), hepatitis B and C (liver cancer), and Helicobacter pylori (stomach cancer). Alcohol consumption accounts for approximately 3.2% of diagnoses, with an established role in cancers of the liver, breast, colorectal, and upper aerodigestive tract.

These three factors combined account for nearly half of all identified preventable cancers. In addition, overweight and obesity, sedentary lifestyles, air pollution, certain occupational exposures, and ultraviolet radiation also contribute significantly to the overall burden.

Marked disparities based on gender and region underscore the importance of structural prevention.

The analysis highlights significant differences in the proportion of cancers attributable to avoidable risk factors by sex, reflecting differing exposure profiles and persistent inequalities in prevention. In 2022, approximately 45.4 per 100,000 new cases diagnosed in men, representing nearly 4.3 million cancers, were linked to modifiable risk factors, compared to 29.7 per 100,000 in women, representing approximately 2.7 million cases. This difference is primarily explained by men's greater exposure to tobacco and alcohol, but also by certain occupational exposures.

In men, smoking alone is the leading cause of cancer, accounting for approximately 23 per 1,000,000 new cases, followed by infections (9 per 1,000,000) and alcohol consumption (4 per 1,000,000). In women, oncogenic infections are the leading cause (approximately 11 per 1,000), particularly human papillomavirus (HPV), which is implicated in cervical cancer, followed by smoking (6 per 1,000) and being overweight or obese (3 per 1,000). These differences reflect varying consumption habits, social contexts, and levels of access to prevention tools, such as vaccination, screening, and smoking cessation programs.

Regional disparities are equally pronounced. Among women, the proportion of preventable cancers varies from approximately 24 per 1,000,000 live births (1/30,000) in North Africa and West Asia to 38 per 1,000,000 live births (1/30,000) in sub-Saharan Africa. Among men, it reaches 57 per 1,000,000 live births (1/30,000) in East Asia, where the burden of smoking and alcohol consumption remains high, compared to 28 per 1,000,000 live births (1/30,000) in Latin America and the Caribbean. These differences reflect variations in exposure to risk factors, but also inequalities in access to prevention, screening, vaccination, and public health policies.

For health agencies, these findings reinforce the need for so-called "structural" public policies, capable of acting at the population level rather than relying solely on individual behavioral changes. These policies include strengthening taxation and regulation of tobacco and alcohol products, expanding vaccination against oncogenic infections, improving access to organized screening programs, reducing environmental and occupational exposures, and promoting environments conducive to physical activity and a balanced diet. Such an integrated approach would not only reduce the overall incidence of cancer, but also lessen social and gender inequalities in the face of disease risk, while protecting healthcare systems strained by the burden of these non-communicable diseases.

©Generation Without Tobacco

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[1] Fink, H., Langselius, O., Vignat, J. et al. Global and regional cancer burden attributable to modifiable risk factors to inform prevention. Nat Med (2026). https://doi.org/10.1038/s41591-026-04219-7

[2] Press release, Four out of ten cancer cases could be prevented worldwide., WHO, published on February 3, 2026, accessed the same day