Nearly 40% of Cancer Cases Globally May Be Preventable
Approximately four in ten cancer cases diagnosed worldwide may be preventable, according to new analysis released today, . An estimated 7.1 million of the 18.7 million global cancer diagnoses in 2022 – equating to 37.9% – could be attributed to modifiable risk factors, according to research by the International Agency for Research on Cancer (IARC) and the World Health Organization (WHO).
The analysis, published in Nature Medicine, coincides with World Cancer Day, an annual observance focused on raising awareness about cancer prevention, detection, and treatment. The findings underscore the significant impact of lifestyle and environmental factors on cancer risk and highlight the potential for reducing the global cancer burden through targeted prevention strategies.
Researchers identified tobacco use as the leading preventable cause of cancer globally, accounting for 15% of all cases in 2022. Infections ranked second, contributing to 10% of cases, while alcohol consumption was responsible for 3%.
Regional and Sex-Based Differences
The impact of these risk factors varies considerably by region and between men and women. “These comparisons demonstrate why a one-size-fits-all prevention strategy is not sufficient,” said Isabelle Soerjomataram, MD, PhD, a medical epidemiologist and deputy head of IARC’s cancer surveillance branch. “Each country and region needs to adapt global and regional strategies and develop prevention priorities that are aligned with their specific cancer burden profile.”
Among men, tobacco is the predominant preventable cause of cancer worldwide, accounting for 45.4% of cases and being the leading factor in 126 out of 185 countries evaluated. For women, infections are the leading preventable cause, responsible for 29.7% of cancer cases and ranking first in 141 of the 185 countries studied. These differences reflect distinct epidemiological factors, cultural norms, and the need for tailored prevention strategies.
The proportion of cancers attributable to modifiable risk factors also differs regionally. Eastern Asia, Central/Eastern Europe, and Western Europe show higher proportions of cancers linked to modifiable factors among men compared to women. Conversely, Southern Africa and Central America demonstrate higher proportions among women compared to men. In North America, the proportion of cancers linked to modifiable risk factors is comparable between both sexes (36.2% vs. 35.9%).
Specific Cancers and Preventable Factors
Three cancer types – lung, stomach, and cervical – account for nearly half of all preventable cancer cases. Smoking and air pollution are major drivers of lung cancer incidence, Helicobacter pylori infection is primarily responsible for stomach cancer, and the human papillomavirus (HPV) is the leading cause of most cervical cancers.
The report highlights the success of prevention efforts in certain areas. Declines in lung cancer incidence in the United States and the United Kingdom, attributed to reductions in tobacco use, and decreases in cervical cancer incidence due to screening and HPV vaccination, demonstrate the effectiveness of policy and public health initiatives.
The Importance of Prevention
The WHO emphasizes that prevention offers the most cost-effective long-term strategy for cancer control. The organization works with member states to strengthen national policies and programs aimed at raising awareness and reducing exposure to cancer risk factors. These include promoting healthy lifestyles, such as a balanced diet, regular physical activity, maintaining a healthy weight, and avoiding smoking and excessive alcohol consumption.
According to the WHO, between 30-50% of all cancer cases are preventable. The agency also notes that alcohol consumption is associated with 740,000 new cancer cases each year globally, and in the European Union, light to moderate alcohol consumption was linked to almost 23,000 new cancer cases in 2017.
Andre Ilbawi, MD, team leader for cancer control at WHO, emphasized the disparities in cancer outcomes. “For a privileged few, access and innovation are driving survival rates beyond 70%,” he said. “But for far too many, cancer remains a death sentence, often compounded by devastating social and financial hardships.”
Ilbawi added, “Today, we are here to celebrate good news founded on strong science: Many cancers are preventable. Prevention strategies are universally relevant. This information is crucial for governments, health systems and individuals, as it highlights where prevention reforms could have the greatest impact.”
The report underscores the importance of a comprehensive approach to cancer prevention, encompassing policy changes, public health initiatives, and individual lifestyle modifications. Further research is needed to understand the complex interplay of risk factors and to develop more effective prevention strategies tailored to specific populations and regions.
