Global Study Maps Avoidable Causes of Cancer
Prevention Could Cut Global Cancer by 40%
WHO Flags Huge Scope for Cancer Prevention Worldwide
Geneva/Lyon: Up to four in ten cancer cases worldwide could be prevented by tackling known risk factors such as tobacco use, alcohol consumption, infections, obesity and air pollution, according to a new global analysis released by the World Health Organization (WHO) and its cancer research arm, the International Agency for Research on Cancer (IARC).
Published ahead of World Cancer Day on February 4, the study estimates that 37 per cent of all new cancer cases in 2022 — about 7.1 million cases — were linked to preventable causes. Drawing on data from 185 countries and covering 36 cancer types, the analysis examines 30 avoidable risk factors, including, for the first time, nine cancer-causing infections.
Tobacco emerged as the single largest preventable cause of cancer worldwide, accounting for 15 per cent of all new cases. This was followed by infections at 10 per cent and alcohol consumption at 3 per cent. Other major contributors included high body mass index, physical inactivity, air pollution and exposure to ultraviolet radiation.
Three cancer types — lung, stomach and cervical cancer — together accounted for nearly half of all preventable cancer cases in both men and women globally.
Lung cancer was primarily linked to smoking and air pollution. Stomach cancer was largely attributable to infection with Helicobacter pylori, while 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 one of the study’s authors. “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.”
The burden of preventable cancer was found to be substantially higher among men than women. About 45 per cent of new cancer cases in men were linked to avoidable causes, compared with 30 per cent in women.
Among men, smoking accounted for an estimated 23 per cent of all new cancer cases, followed by infections at 9 per cent and alcohol at 4 per cent. Among women globally, infections were the leading preventable cause at 11 per cent, followed by smoking at 6 per cent and high body mass index at 3 per cent.
Regional differences were also striking. Among women, 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 proportion was observed in East Asia at 57 per cent, while the lowest was in Latin America and the Caribbean at 28 per cent.
These variations reflect differences in exposure to behavioural, environmental, occupational and infectious risks, as well as disparities in socioeconomic development, national prevention policies and health system capacity.
“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.”
The report highlights the importance of context-specific prevention strategies, including strong tobacco control measures, regulation of alcohol, vaccination against cancer-causing infections such as HPV and hepatitis B, improved air quality, safer workplaces, and healthier food and physical activity environments.
WHO and IARC stressed that preventing cancer requires coordinated action across sectors beyond health, including education, energy, transport and labour. Such measures, they said, could prevent millions of families from facing a cancer diagnosis while also reducing long-term healthcare costs and improving overall population well-being.
In a note accompanying the release, WHO said it would continue working with governments to strengthen cancer prevention, early detection, treatment and palliative care, while supporting global initiatives on cervical, breast and childhood cancers.
The findings underscore a central message ahead of World Cancer Day: a large share of the world’s cancer burden is not inevitable and can be reduced through sustained public health action on known, preventable risks.
– global bihari bureau
