Nearly 40% of Cancers Globally Are Preventable: New Study Reveals Key Risk Factors

Nearly 40 percent of all cancer cases worldwide are potentially preventable, according to a new global analysis of cancer data. The research, published in February 2026, estimates that approximately seven million cancer diagnoses each year are linked to modifiable risk factors – those that can be changed, controlled, or managed.

Preventable Factors Behind Millions of Cases

The study, led by researchers at the International Agency for Research on Cancer (IARC), part of the World Health Organization (WHO), analyzed data from 2022, looking back at risk factor exposure a decade earlier across 185 countries. Researchers examined 30 known preventable factors, including lifestyle choices, infections, and environmental pollutants.

Tobacco smoking emerged as the leading contributor to preventable cancer cases globally, responsible for an estimated 3.3 million cancers. Infections were the second largest contributor, and alcohol consumption also played a significant role. Specifically, cancers like cervical cancer, often caused by the human papillomavirus (HPV), are preventable through vaccination. Stomach cancer is frequently linked to the bacterium Helicobacter pylori.

“This is the first global analysis to show how high the risk of cancer is from preventable causes,” said Dr. André Ilbawi, head of the WHO cancer control team. The researchers emphasize that this high percentage – nearly four in ten cancers – represents a “powerful opportunity” to transform the lives of millions.

Regional and Gender Differences

The proportion of preventable cancer cases varies significantly by region and gender. In sub-Saharan Africa, approximately 38 percent of cancer cases in women are considered preventable, while in North Africa and Western Asia, that figure drops to just under 25 percent. Infections are a more prominent preventable cause of cancer in Africa and Asia.

Among men, the highest proportion of preventable cancer cases is found in East Asia, exceeding 57 percent, while Latin America and the Caribbean have the lowest rate, around 28 percent. In Europe, Australia, the USA, and Canada, smoking is a particularly important preventable risk factor.

The Situation in Germany

Data specific to Germany reveals that around 30 percent of cancer cases in women and nearly 39 percent in men are attributable to avoidable factors. Smoking alone accounts for over 12 percent of new cancer cases among women and more than 23 percent among men. Other significant contributors include alcohol consumption, a high body mass index, exposure to ultraviolet (UV) radiation, and infections.

Occupational risks, such as exposure to carcinogenic substances, are more prevalent among men in Germany (5.8 percent) compared to women (1.6 percent). However, the analysis suggests that too little exercise and air pollution play a relatively minor role in cancer cases within Germany.

Beyond Lifestyle: Environmental and Occupational Risks

The study considered not only behavioral risks like smoking and alcohol consumption but also environmental factors like air pollution and occupational hazards. These factors can directly damage DNA or alter inflammation and hormones in the body, increasing cancer risk.

Looking Ahead: A Growing Global Burden

While the study highlights the potential for prevention, it also acknowledges the increasing global cancer burden. The Lancet has projected that the number of new cancer cases worldwide will rise by 61 percent over the next 25 years, reaching 30.5 million by 2050. The annual global cancer death toll is forecast to increase by nearly 75 percent to 18.6 million, driven largely by population growth and aging populations.

Researchers emphasize the need for greater efforts from policymakers, governments, and agencies to prevent, diagnose, and treat cancer at all levels. Addressing these preventable risk factors is seen as one of the most effective strategies for reducing the future cancer burden. As Dr. Isabelle Soerjomataram from the IARC noted, many people are surprised to learn that nearly four in ten cancers are preventable, highlighting the potential for significant impact through targeted interventions.

The study authors used data on cancer cases from 2022 and from the 30 risk factors a decade earlier to perform their statistical analysis. The research was published in Nature Medicine.