Nearly 40% of Cancer Cases Are Preventable: WHO Study Reveals Key Risk Factors

Nearly 40% of new cancer cases worldwide could be preventable, according to a new analysis released by the World Health Organization (WHO) and its International Agency for Research on Cancer (IARC). The findings, published on February 3, 2026, highlight the significant impact of modifiable risk factors on cancer incidence and underscore the potential for prevention through public health interventions and lifestyle changes.

The study examined data from 185 countries and 36 cancer types, identifying 30 preventable risk factors. Approximately 7.1 million new cancer cases in 2022 – roughly 37% of the total – were linked to these factors. This analysis builds on previous research, offering a more comprehensive look at preventability by focusing on cases rather than deaths and considering a wider range of risk factors.

Tobacco Use Remains the Leading Preventable Cause

Tobacco smoking stands out as the most significant preventable cause of cancer globally, accounting for 15% of all new cases. The impact is particularly pronounced in men, where smoking contributed to 23% of cancer diagnoses in 2022. This reinforces existing public health efforts aimed at tobacco control and cessation.

Beyond Smoking: Infections, Alcohol, and Other Risk Factors

While tobacco use is the leading cause, other modifiable risk factors play a substantial role. Infections are responsible for approximately 10% of all new cancer cases. Among women, high-risk human papillomavirus (HPV) is a major contributor to preventable cancers, specifically cervical cancer. Fortunately, a vaccine for HPV exists and can prevent many associated diseases, though vaccination coverage remains insufficient in many regions.

Alcohol consumption accounts for 3.2% of all new cancer cases, equating to roughly 700,000 diagnoses globally in 2022. Other significant preventable risk factors include high body mass index, physical inactivity, smokeless tobacco, areca nut use, suboptimal breastfeeding, air pollution, and exposure to ultraviolet radiation.

Regional Variations in Preventable Cancer Cases

The study revealed considerable regional variations in the prevalence of preventable cancers. For example, air pollution contributes to approximately 15% of lung cancer cases in women in East Asia. In Northern Africa and Western Asia, around 20% of lung cancer cases in men are linked to air pollution. These regional differences highlight the need for tailored prevention strategies that address specific local risk factors.

Impact on Specific Cancer Types

Lung, stomach, and cervical cancers represent nearly half of all preventable cancer cases in both men and women. Stomach cancer cases are more common in men and are often associated with smoking and infections related to overcrowding, inadequate sanitation, and limited access to clean water.

The Importance of Proactive Prevention

The WHO analysis emphasizes the urgent need for effective prevention strategies to address the projected 50% increase in new cancer cases by 2040 if current trends continue. “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,” said Dr. André Ilbawi, WHO Team Lead for Cancer Control and co-author of the study.

The findings were released ahead of World Cancer Day, observed annually on February 4, 2026, serving as a critical reminder of the potential to reduce the global cancer burden through proactive prevention efforts. Addressing these preventable causes represents a powerful opportunity to improve global health outcomes.

The study was published in Nature Medicine.