According to a study released by the World Health Organization (WHO) on the occasion of World Cancer Day, nearly 40 percent of cancer cases worldwide could be prevented by avoiding known risk factors that contribute to the disease.
The research highlights that behaviors and exposures such as tobacco use, alcohol consumption, air pollution, and certain infections account for a significant portion of cancer risk. In 2022 alone, the study estimates that 37 percent—or roughly 7.1 million—new cancer cases could have been prevented.
Key Risk Factors and Preventable Cancers
The WHO’s International Agency for Research on Cancer (IARC) analyzed 30 factors that increase cancer risk. Findings include:
Tobacco use is linked to 15 percent of all cancer cases.
Other major contributors include infectious agents (10 percent) and alcohol consumption (3 percent).
Additional risk factors include obesity, physical inactivity, ultraviolet (UV) exposure from sunlight, and air pollution.
The study emphasizes that cancers with the highest potential for prevention—nearly 50 percent of cases—include lung, stomach, and cervical cancers. Lung cancer is primarily associated with tobacco use and air pollution, stomach cancer is linked to Helicobacter pylori infection, and cervical cancer is mostly caused by HPV, against which vaccines are effective.
Gender Differences in Preventable Cancer Cases
The research indicates that men have a higher proportion of preventable cancer cases compared to women—45 percent versus 30 percent. Among these, about one-quarter of preventable cancers in men are due to tobacco, compared with 11 percent in women.
WHO experts called on governments worldwide to implement strict tobacco control measures, ensure access to vaccines for preventable infections such as HPV, improve air quality, promote healthy diets, and encourage physical activity.
The study concludes that reducing the global cancer burden requires addressing other non-communicable disease risk factors as well, including tobacco, alcohol, ultra-processed foods, and environmental pollutants.
This research represents the first global analysis demonstrating that a significant portion of cancer cases could be avoided through targeted prevention strategies.