Up to four in every 10 new cancer cases worldwide could be prevented through behavioural changes, stronger public health policies and targeted prevention strategies, according to a new global analysis by the World Health Organisation (WHO).
The findings, released this week to mark World Cancer Day on February 4, 2026, are based on a Nature Medicine study that examined data from 185 countries across 36 cancer types.
The analysis estimates that about 37 per cent of the 18.7 million new cancer cases recorded globally in 2022 were linked to modifiable risk factors, including tobacco use, infections and lifestyle-related exposures.
“The science is clear,” said Dr Maria Neira, WHO Director of Environment, Climate Change and Health. “A large proportion of cancers particularly those associated with tobacco, infections and unhealthy environments are not inevitable. They are preventable.”
Tobacco use remains the single largest avoidable cause of cancer worldwide, accounting for roughly 15 per cent of all new cases. Infectious agents, notably human papillomavirus (HPV) and Helicobacter pylori, were responsible for about 10 per cent of cases combined, the report found.
“Smoking and infection-related cancers continue to exact an enormous toll,” said Dr Elisabete Weiderpass, Director of the International Agency for Research on Cancer (IARC), a WHO agency. “Effective prevention is not only possible, it must be prioritised.”
Vaccines, behaviour change and policy action
The report highlights cervical cancer as one of the clearest examples of preventable disease, noting that it is overwhelmingly caused by HPV, for which safe and effective vaccines are available. Cancers linked to H. pylori infection, often associated with poor sanitation and limited access to screening were also identified as largely preventable.
“We are at a point where public health interventions such as HPV vaccination, tobacco control and healthier environmental policies could save millions of lives,” Weiderpass said.
The analysis also revealed sharp disparities in preventable cancer burdens by sex and region. Among men, about 45 per cent of cancers were attributed to modifiable risk factors, compared with roughly 30 per cent among women.
Regional variations were also significant, with East Asia, Latin America, North Africa and West Asia showing differing patterns of exposure driven by lifestyle, environmental conditions and access to preventive care.
“These differences reflect variations in behaviour, environment and health system capacity,” Neira said. “That is why prevention strategies must be tailored to local realities.”
Prevention as a global priority
The WHO is calling on governments and health authorities to expand proven prevention measures, including tobacco taxation, public smoking bans, widespread vaccination programmes and improved air quality standards.
“We need to shift the focus upstream,” Neira said. “Investing in prevention saves lives, reduces long-term healthcare costs and strengthens health systems.”
While cancer remains one of the world’s leading causes of death, the WHO stressed that nearly 40 per cent of cases could be avoided through coordinated public health action, political commitment and community engagement, underscoring prevention as one of the most powerful tools in the global fight against cancer.
