An estimated 38% of all new cancer cases diagnosed worldwide in 2022 were linked to preventable or modifiable risk factors, according to a comprehensive analysis published in Nature Medicine.
The study, conducted by researchers from the World Health Organization (WHO) and the International Agency for Research on Cancer (IARC), examined 36 different types of cancer across 185 countries.
Study Methodology and Scope
Researchers analyzed global case data from 2022, combining it with 2012 exposure data to estimate the proportion of cancers directly attributable to 30 well-established modifiable risk factors.
These factors include tobacco smoking, alcohol consumption, high body mass index, insufficient physical activity, smokeless tobacco, areca nut, suboptimal breastfeeding, air pollution, ultraviolet radiation, infectious agents, and various occupational exposures.
Out of approximately 18.7 to 19 million new cancer cases reported globally in 2022, an estimated 7.1 million cases were attributed to these factors.
Leading Risk Factors
- Tobacco Smoking: Identified as the leading preventable factor, associated with approximately 15% of all cancer cases. For men, smoking contributed to 23% of all new cancer cases.
- Infections: Linked to approximately 10% of new cancer cases. Among women, high-risk human papillomavirus (HPV) was a major contributor, particularly to cervical cancer.
- Alcohol Consumption: Accounted for roughly 3.2% of new cancer cases, totaling approximately 700,000 cases.
- Air Pollution: Contributed to lung cancer cases, with impact varying by region. For example, it accounted for approximately 15% of lung cancer cases in women in East Asia and 20% in men in Northern Africa and Western Asia.
Most Preventable Cancer Types
Lung, stomach, and cervical cancers collectively constituted nearly half of all preventable cancer cases. Stomach cancer cases were noted as more prevalent in men and were frequently associated with smoking and infections linked to overcrowding, inadequate sanitation, and limited access to clean water.
"Addressing these risk factors through medical intervention, behavioral modifications, reduction of occupational hazards, and mitigation of environmental pollutants could reduce the global cancer burden."
Potential Prevention Strategies
Prevention strategies identified by the researchers include:
- Vaccination (e.g., the HPV vaccine)
- Behavior changes (e.g., reducing smoking and alcohol consumption)
- Environmental improvements
Authors and Publication
The analysis was published in Nature Medicine. Key contributors include Hanna Fink (cancer epidemiologist at WHO/IARC), Isabelle Soerjomataram (medical epidemiologist at WHO and senior author), and André Ilbawi (WHO Team Lead for Cancer Control and co-author).