Four out of ten cancer cases could be prevented globally

Up to four out of ten cancer cases in the world 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 examines 30 preventable causes, including tobacco, alcohol, high body mass index, physical inactivity, air pollution, ultraviolet radiation – and for the first time – nine cancer-causing infections.

Published ahead of World Cancer Day on February 4, the analysis estimates that 37% of all new cancer cases in 2022, around 7.1 million cases, were linked to preventable causes. The findings highlight the enormous potential of prevention in reducing the global burden of cancer.

Drawing on data from 185 countries and 36 types of cancer, the study identifies tobacco as the leading preventable cause of cancer, globally responsible for 15% of all new cancer cases, followed by infections (10%) and alcohol consumption (3%).

Three types of cancer – lung, stomach and cervical cancer – account for almost half of all preventable cancers in both men and women worldwide.

Lung cancer was primarily associated with smoking and air pollution, and stomach cancer was largely attributed to it Helicobacter pylori infections, and cervical cancer is mostly caused by the human papillomavirus (HPV).

“This is the first global analysis to show how much cancer risk comes from preventable causes,” said Dr. André Ilbawi, head of the WHO Cancer Control Team and author of the study. “By examining patterns across countries and population groups, we can provide governments and individuals with more precise information to prevent many cases of cancer before they start.”

Differences between men, women and in regions

The burden of preventable cancer was significantly higher in men than in women, with 45% of new cancer cases in men compared to 30% in women. In men, smoking accounted for an estimated 23% of all new cancer cases, followed by infections at 9% and alcohol at 4%. Among women worldwide, infections accounted for 11% of all new cancer cases, followed by smoking with 6% and high body mass index with 3%.

“This landmark study is a comprehensive assessment of preventable cancer worldwide, including for the first time infectious causes of cancer in addition to behavioral, environmental and occupational risks,” said Dr. Isabelle Soerjomataram, deputy head of IARC’s Cancer Surveillance Unit and senior author of the study. “Addressing these preventable causes represents one of the most powerful opportunities to reduce the global burden of cancer.”

Preventable cancer varies greatly from region to region. Among women, preventable cancers ranged from 24% in North Africa and West Asia to 38% in sub-Saharan Africa. Among men, the highest burden was recorded in East Asia at 57%, and the lowest in Latin America and the Caribbean at 28%. These differences reflect different exposure to behavioral, environmental, occupational and infectious risk factors, as well as differences in socioeconomic development, national preventive policies and health system capacities.

The findings highlight the need for context-specific prevention strategies that include strong tobacco control measures, alcohol regulation, vaccination against cancer-causing infections such as human papillomavirus (HPV) and hepatitis B, improved air quality, safer workplaces, and healthier food and physical activity environments.

Coordinated action across all sectors, from health and education to energy, transport and labour, can prevent millions of families from experiencing the burden of a cancer diagnosis. Addressing preventable risk factors not only reduces cancer incidence, but also lowers long-term health care costs and improves population health and well-being.

Note to the editor:

WHO and its specialized cancer research agency IARC are working together to strengthen cancer prevention, early detection, treatment and palliative care worldwide. They provide technical guidance, define global and regional standards and support governments to improve access and reduce inequalities. Their efforts also include promoting research, policy and global initiatives on cervical, breast and childhood cancer.