Nearly 40% of Cancers Globally Are Preventable: WHO Study

Nearly four in ten cancer cases globally may be preventable, according to a new analysis released today, February 3, 2026, by the World Health Organization (WHO) and its International Agency for Research on Cancer (IARC). The study, published in the medical journal Nature Medicine, identifies 30 modifiable risk factors responsible for approximately 37% of all new cancer cases in 2022 – around 7.1 million diagnoses.

This finding, released ahead of World Cancer Day on February 4th, underscores a powerful opportunity to reduce the global burden of cancer through preventative measures. Researchers examined data from 185 countries and 36 cancer types to arrive at these conclusions.

Tobacco, Infections, and Alcohol: Leading Preventable Causes

Tobacco use remains the single largest preventable cause of cancer, accounting for 15% of all new cases. Infections are responsible for 10%, and alcohol consumption contributes to 3% of cases. Specifically, lung, stomach, and cervical cancers represent nearly half of all preventable cancer cases in both men and women.

“We now have the information to prevent cancer before it starts,” said Isabelle Soerjomataram, a cancer surveillance specialist at IARC. This suggests that altering behaviors and addressing environmental factors can significantly impact cancer incidence.

A Deeper Look at Modifiable Risk Factors

The study considered a wide range of modifiable risk factors, including high body mass index, physical inactivity, air pollution, and ultraviolet radiation. For the first time, the analysis also incorporated nine cancer-causing infections, such as the human papillomavirus (HPV), which can cause cervical cancer, and hepatitis B.

The impact of these risk factors varies by sex. Among men, tobacco use accounts for approximately 23% of all new cancer cases, followed by infections (9%) and alcohol (4%). In women, infections are responsible for 11% of new cases, with tobacco contributing to 6% and a high body mass index accounting for 3%.

Specific Cancers Linked to Preventable Factors

The analysis highlights specific links between preventable factors and certain cancer types. Lung cancer is strongly associated with smoking and air pollution. Stomach cancer is largely attributed to infection with the bacterium Helicobacter pylori. Cervical cancer is predominantly caused by HPV.

The Need for Targeted Prevention Strategies

The WHO emphasizes the need for tailored prevention strategies that address specific regional and population-level risk factors. These strategies include robust tobacco control measures, regulation of alcohol consumption, vaccination against cancer-causing infections like HPV and hepatitis B, improved air quality, safer workplaces, and environments that promote healthy diets and physical activity.

“These three factors [tobacco, infections, and alcohol] alone represent the vast majority” of cancer cases linked to preventable causes, according to Soerjomataram. This underscores the potential impact of focused prevention efforts.

A Coordinated Approach is Crucial

Effective cancer prevention requires a coordinated effort across multiple sectors, including health, education, energy, transportation, and labor. The WHO believes that such collaboration can prevent millions of families from experiencing the hardship of a cancer diagnosis.

Andre Ilbawi, WHO Team Lead for Cancer Control and author of the study, stated that the findings demonstrate that the number of new cancer cases “can be altered” through preventative measures at various levels. The study’s findings offer a hopeful message: a significant proportion of cancer cases are not inevitable and can be avoided through proactive public health interventions and individual lifestyle choices.

The WHO estimates that projections point to a 50% increase in new cancer cases by 2040 if current trends continue, further emphasizing the urgent need for effective prevention strategies.