Up to four in ten cancer cases worldwide could be prevented, according to a major new analysis released by the World Health Organization (WHO) and its International Agency for Research on Cancer (IARC). The global study examines 30 preventable causes of cancer, including tobacco use, alcohol consumption, high body mass index, physical inactivity, air pollution, and ultraviolet radiation. For the first time, the analysis also includes nine cancer-causing infections.

Published ahead of World Cancer Day on 4 February, the report estimates that 37% of all new cancer cases in 2022, around 7.1 million cases, were linked to preventable risk factors. Researchers say the findings highlight the massive opportunity for cancer prevention strategies to reduce the global burden of disease.

The study used data from 185 countries and reviewed 36 cancer types, identifying tobacco as the leading avoidable cause. Smoking was responsible for 15% of all new cancer cases worldwide, followed by infections (10%) and alcohol consumption (3%).

Tobacco, Infections, and Alcohol Are Major Global Cancer Drivers

The analysis found that three cancer types, lung, stomach, and cervical cancer, accounted for nearly half of all preventable cancer cases in both men and women globally.

Lung cancer was mainly linked to smoking and air pollution, stomach cancer was largely connected 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 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.”

Major Differences Found Between Men, Women, and Global Regions

The study found a significant gap between men and women when it comes to preventable cancer. Globally, 45% of new cancer cases in men were linked to preventable causes, compared to 30% in women.

Among men, smoking was the dominant risk factor, accounting for 23% of all new cancer cases, followed by infections (9%) and alcohol (4%). Among women worldwide, infections were the leading preventable cause at 11%, followed by smoking (6%) and high body mass index (3%).

“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 Vary Widely by Region

Researchers found that preventable cancer levels differ greatly depending on geography, health policies, and exposure to risk factors.

Among women, preventable cancer cases ranged from 24% in North Africa and West Asia to 38% in sub-Saharan Africa. Among men, the highest preventable cancer burden was recorded in East Asia at 57%, while the lowest was in Latin America and the Caribbean at 28%.

The report notes that these regional differences are influenced by multiple factors, including behavioural patterns, environmental exposure, occupational risks, infectious diseases, socioeconomic conditions, prevention policies, and health system capacity.

Prevention Could Significantly Reduce the Global Cancer Burden

The findings emphasize the need for prevention strategies tailored to each country and region. Recommended actions include stronger tobacco control, tighter alcohol regulation, improved air quality policies, safer working conditions, and better support for healthy diets and physical activity.

The report also highlights the importance of vaccination and infection control, particularly against cancer-causing infections such as HPV and hepatitis B.

Health officials stress that cancer prevention requires collaboration beyond the health sector. Policies involving education, transport, labour, energy, and environmental planning can play a critical role in reducing cancer risk.

Coordinated action across sectors could prevent millions of people from facing the burden of cancer. Addressing preventable causes not only lowers cancer incidence but also reduces long-term health-care costs and supports healthier populations worldwide.