Up to four in ten cancer cases worldwide could be prevented, according to a new global analysis from the World Health Organization (WHO) and its International Agency for Research on Cancer (IARC). The study, released ahead of , examines 30 preventable causes, including well-established risk factors like tobacco and alcohol, as well as emerging considerations such as air pollution, physical inactivity, and, for the first time, nine cancer-causing infections.
The analysis estimates that 37% of all new cancer cases in , approximately 7.1 million cases, were linked to preventable causes. This finding underscores the significant potential for reducing the global cancer burden through targeted prevention strategies.
Drawing on data from 185 countries and 36 cancer types, the study identifies tobacco use as the leading preventable cause of cancer globally, responsible for 15% of all new cases. Infections account for 10%, and alcohol consumption for 3%. Specifically, lung, stomach, and cervical cancers represent nearly half of all preventable cancer cases in both men and women.
The link between specific risk factors and cancer types is particularly notable. Lung cancer is primarily associated with smoking and exposure to air pollution, stomach cancer is largely attributable to infection with Helicobacter pylori, and cervical cancer is overwhelmingly caused by the human papillomavirus (HPV). These connections highlight the importance of addressing these specific risk factors to reduce the incidence of these cancers.
“Here’s 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 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.”
Disparities in Cancer Preventability
The burden of preventable cancer varies significantly between men and women. The study found that 45% of new cancer cases in men are linked to preventable causes, compared to 30% in women. Among men, smoking accounts for an estimated 23% of all new cancer cases, followed by infections at 9% and alcohol at 4%. For women, infections are a more prominent factor, accounting for 11% of all new cancer cases, followed by smoking at 6% and high body mass index at 3%.
Geographic variations are also substantial. Among women, preventable cancers range from 24% in North Africa and West Asia to 38% in sub-Saharan Africa. Among men, the highest burden was observed in East Asia at 57%, and the lowest in Latin America and the Caribbean at 28%. These differences reflect varying levels of exposure to behavioral, environmental, occupational, and infectious risk factors, as well as differences in socioeconomic development, national prevention policies, and the capacity of health systems.
Implications for Public Health
The findings underscore the critical need for context-specific prevention strategies. These strategies should include robust tobacco control measures, effective alcohol regulation, widespread vaccination against cancer-causing infections like HPV and hepatitis B, improvements in air quality, safer workplaces, and environments that promote healthy diets and physical activity.
“Addressing these preventable causes represents one of the most powerful opportunities to reduce the global cancer burden,” said Dr. Isabelle Soerjomataram, Deputy Head of the IARC Cancer Surveillance Unit and senior author of the study.
Effective cancer prevention requires coordinated action across multiple sectors, including health, education, energy, transport, and labor. Such a comprehensive approach can not only reduce the incidence of cancer but also lower long-term healthcare costs and improve overall population health and well-being.
The WHO and IARC continue to work together to strengthen cancer prevention, early detection, treatment, and palliative care worldwide. Their efforts include providing technical guidance, defining global and regional standards, and supporting governments in improving access to care and reducing health inequalities. They also drive research, policy, and global initiatives focused on cancers like cervical, breast, and childhood cancers.
