37% of cancers worldwide are caused by preventable factors

Up to 40% of cancer cases worldwide are preventable, according to a new global analysis published by the World Health Organization (WHO) and its International Agency for Research on Cancer (IARC). This study, released ahead of World Cancer Day on February 4, estimated that 37% of all new cancer cases, or approximately 7.1 million cases, by 2022 are related to preventable causes.

This study analyzed 30 preventable causes, including smoking, drinking, high body mass index (BMI), physical inactivity, air pollution, and ultraviolet rays, based on data on 36 cancer types in 185 countries. In particular, this analysis also included nine cancer-causing infections for the first time.

Cigarettes are the biggest risk factor, followed by infections and drinking.

As a result of the study, smoking accounted for 15% of new cancer cases worldwide and was identified as the most preventable cause. This was followed by infection at 10% and alcohol consumption at 3%. Three cancer types - lung cancer, stomach cancer, and cervical cancer - accounted for nearly half of all preventable cancer cases in both men and women.

It was analyzed that lung cancer is mainly caused by smoking and air pollution, stomach cancer is mainly caused by Helicobacter pylori infection, and cervical cancer is mostly caused by human papillomavirus (HPV) infection.

“This is the first global analysis showing how much cancer risk comes from preventable causes,” said Dr. André Ilbawi, head of the WHO cancer control team and author of the study. “By analyzing patterns by country and population group, we can provide governments and individuals with specific information for cancer prevention.”

Disparities by gender and region are clear

The burden of preventable cancer differed significantly by gender. For men, 45% of new cancer cases were related to preventable factors, compared to only 30% for women. In men, smoking accounted for 23% of all new cancers, followed by infections at 9% and drinking at 4%. Among women, infection was the highest at 11%, followed by smoking at 6% and high BMI at 3%.

There were also large regional differences. The rate of preventable cancer among women was lowest in North Africa and Western Asia at 24%, and highest in sub-Saharan Africa at 38%. Among men, East Asia recorded the highest rate at 57%, and Latin America and the Caribbean recorded the lowest rate at 28%. These differences reflect differences in exposure to behavioral, environmental, occupational and infectious risk factors, level of socioeconomic development, national prevention policies, and health system capacity.

When did this trend start?

International interest in cancer prevention has steadily increased over the past several decades. Since the early 2000s, WHO has promoted the Framework Convention on Tobacco Control (FCTC) with tobacco control as a key task, and the distribution of HPV and hepatitis B vaccines has expanded in the 2010s. Entering the 2020s, interest in environmental and lifestyle factors such as air pollution and obesity has increased. This study is the most comprehensive global analysis that includes infectious causes in this trend, providing new evidence for prevention-focused cancer response strategies.

Impact on Korea

Korea is one of the countries with the highest incidence of stomach cancer in the world, and control of Helicobacter pylori infection is particularly important. In addition, despite the decline in smoking rates, the incidence of lung cancer is still high, necessitating the strengthening of air pollution measures and smoking cessation policies. The results of this study are expected to serve as an important reference for the Korean government in establishing cancer prevention policies.

Future outlook [AI analysis]

This study highlights the need for context-specific tailored prevention strategies. Strong tobacco regulations, alcohol regulations, expansion of HPV and hepatitis B vaccinations, improvement of air quality, safe working environment, and creation of a healthy diet and physical activity environment were presented as key tasks.

“Addressing these preventable causes is the most powerful opportunity to reduce the global burden of cancer,” said Dr. Isabelle Soerjomataram, IARC Deputy Director of Cancer Surveillance and senior author of the study.

It is expected that millions of families will be able to escape the pain of a cancer diagnosis if a cooperative response is made across various sectors, including health, education, energy, transportation, and labor. Addressing preventable risk factors is likely to not only reduce cancer incidence but also reduce long-term medical costs and improve the health of the population as a whole.