By Ayomide Otitoju
Up to four in ten cancer cases worldwide could be prevented, according to a new global analysis by the World Health Organization (WHO) and its International Agency for Research on Cancer (IARC). The study, released ahead of World Cancer Day on 4 February, examined 30 preventable causes of cancer, including tobacco, alcohol, high body mass index, physical inactivity, air pollution, ultraviolet radiation, and—for the first time—nine cancer-causing infections.
The analysis estimates that 37% of all new cancer cases in 2022, approximately 7.1 million cases, were linked to preventable causes, highlighting the critical role of prevention in reducing the global cancer burden. Drawing on data from 185 countries and 36 cancer types, tobacco emerged as the leading preventable cause, responsible for 15% of new cases globally, followed by infections (10%) and alcohol consumption (3%).
Lung, stomach, and cervical cancers accounted for nearly half of all preventable cases. Lung cancer was primarily associated with smoking and air pollution, stomach cancer with Helicobacter pylori infection, and cervical cancer with 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. “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 study found that preventable cancers were more common in men than women, with 45% of new male cases versus 30% in women. Among men, smoking accounted for 23% of new cases, followed by infections at 9% and alcohol at 4%. In women, infections accounted for 11% of new cases, followed by smoking at 6% and high body mass index at 3%.
“This landmark study is a comprehensive assessment of preventable cancer worldwide, incorporating infectious causes alongside behavioural, environmental, and occupational risks,” said Dr Isabelle Soerjomataram, Deputy Head of the IARC Cancer Surveillance Unit. “Addressing these preventable causes represents one of the most powerful opportunities to reduce the global cancer burden.”
Preventable cancer prevalence varied by region. Among women, it ranged from 24% in North Africa and West Asia to 38% in sub-Saharan Africa. Among men, the highest burden was in East Asia at 57%, and the lowest in Latin America and the Caribbean at 28%. These differences reflect variations in risk exposure, national prevention policies, and health system capacities.
The findings underscore the need for context-specific prevention strategies, including tobacco and alcohol regulation, vaccination against cancer-causing infections such as HPV and hepatitis B, improved air quality, safer workplaces, and promotion of healthy diets and physical activity. Coordinated action across sectors—including health, education, energy, transport, and labour—can prevent millions of cancers, reduce long-term health-care costs, and improve population well-being.
