4 in 10 Cancer Cases Worldwide Could Be Prevented, WHO and IARC Find.
Geneva / Lyon:
Up to 40 per cent of cancer cases globally could be prevented by addressing known risk factors, according to a major new analysis released by the World Health Organization (WHO) and its International Agency for Research on Cancer (IARC).
Published ahead of World Cancer Day on 4 February, the study estimates that 37 per cent of all new cancer cases diagnosed worldwide in 2022 — around 7.1 million cases — were linked to preventable causes. The findings underline the critical role of prevention in reducing the global cancer burden.
The analysis examined 30 preventable risk factors across 185 countries and 36 cancer types. These include tobacco use, alcohol consumption, high body mass index, physical inactivity, air pollution, ultraviolet radiation, and — for the first time in a global assessment — nine cancer-causing infections.
Tobacco use emerged as the leading preventable cause of cancer worldwide, accounting for 15 per cent of all new cancer cases. Infections were responsible for 10 per cent, while alcohol consumption contributed to 3 per cent of cases.
The study found that lung, stomach and cervical cancers together accounted for nearly half of all preventable cancer cases globally, in both men and women. Lung cancer was primarily associated with smoking and air pollution, stomach cancer was largely linked to Helicobacter pylori infection, and cervical cancer was overwhelmingly caused by human papillomavirus (HPV).
“This is the first global analysis to show how much cancer risk comes from causes we can prevent,” said Dr André Ilbawi, WHO Team Lead for Cancer Control and an author of the study. “By examining patterns across countries and population groups, we can provide governments and individuals with more specific information to help prevent many cancer cases before they start.”
Differences by sex and region
The burden of preventable cancer was significantly higher among men than women. An estimated 45 per cent of new cancer cases in men were linked to preventable causes, compared with 30 per cent in women.
Among men, smoking accounted for 23 per cent of all new cancer cases, followed by infections (9 per cent) and alcohol consumption (4 per cent). Among women globally, infections were the leading preventable cause at 11 per cent, followed by smoking (6 per cent) and high body mass index (3 per cent).
“This landmark study is a comprehensive assessment of preventable cancer worldwide, incorporating for the first time infectious causes of cancer alongside behavioural, environmental, and occupational risks,” said Dr Isabelle Soerjomataram, Deputy Head of the IARC Cancer Surveillance Unit and senior author of the study. “Addressing these preventable causes represents one of the most powerful opportunities to reduce the global cancer burden.”
Preventable cancer rates varied widely across regions. Among women, the proportion of preventable cancers ranged from 24 per cent in North Africa and West Asia to 38 per cent in sub-Saharan Africa. Among men, the highest burden was observed in East Asia at 57 per cent, while the lowest was in Latin America and the Caribbean at 28 per cent.
These regional differences reflect varying exposure to behavioural, environmental, occupational and infectious risk factors, as well as disparities in socioeconomic development, national prevention policies and health system capacity.
Call for stronger prevention measures
WHO and IARC emphasized the need for tailored, context-specific prevention strategies. These include stronger tobacco control and alcohol regulation, vaccination against cancer-causing infections such as HPV and hepatitis B, improved air quality, safer workplaces, and healthier environments that support good nutrition and physical activity.
The agencies also highlighted the importance of coordinated action across sectors — including health, education, energy, transport and labour — to effectively reduce cancer risk.
Addressing preventable risk factors, the report notes, could spare millions of families from the physical, emotional and financial burden of cancer, while also reducing long-term health-care costs and improving overall population health and well-being.
