The study led by the World Health Organization (WHO) and the International Agency for Research on Cancer (IARC) examines 30 preventable causes, including tobacco, alcohol, high body mass index, physical inactivity, air pollution and ultraviolet rays.
Nine cancer-causing infections – such as human papillomavirus (HPV), which can cause cervical cancer – are also included for the first time.
Examine prevention models
Cancer remains a major cause of morbidity, responsible for nearly 10 million deaths worldwide in 2020, or nearly one in six.
Projections indicate a 50 percent increase in new cases by 2040 if current trends continue, highlighting the urgent need for effective prevention strategies.
The study was published ahead of World Cancer Day, celebrated annually on February 4.
The findings are based on data from 185 countries and 36 cancer types. Estimates show that 37 percent of all new cancer cases in 2022, or about 7.1 million, were linked to preventable causes.
“By examining trends across countries and population groups, we can provide governments and individuals with more specific information to help prevent many cases of cancer before they start,” said Dr André Ilbawi, head of the WHO cancer team and author of the study.
First cause of tobacco
Tobacco is the leading preventable cause of cancer, responsible for 15 percent of all new casesfollowed by infections (10 percent) and alcohol consumption (3 percent).
Lung, stomach and cervical cancers accounted for almost half of all preventable cases in both men and women.
Lung cancer was mainly linked to smoking and air pollution, while stomach cancer was largely attributable to Helicobacter pylori infection. Cervical cancer was mainly caused by HPV.
Differences between men and women
The burden of preventable cancer was significantly higher in men than in women. Among new cases of cancer, 45 percent occur in men, compared to 30 percent in women.
Among men, smoking accounted for about 23 percent of all new cancer cases, followed by infections (9 percent) and alcohol (4 percent).
Among women, infections accounted for 11 percent of all new cancer cases, followed by smoking at 6 percent and high body mass index at 3 percent.
Regional table, risk factors
Preventable cancers also vary widely across regions of the world.
Among women, they ranged from 24 percent in North Africa and West Asia, to 38 percent in sub-Saharan Africa.
Among men, East Asia accounted for the heaviest burden at 57 percentwhile the the lowest incidence was observed in Latin America and the Caribbean, at 28 percent..
These differences are largely due to varying exposure to behavioral, environmental, occupational and infectious risk factors, as well as differences in socio-economic development, national prevention policies and health system capacity.
Prevention strategies
The report highlights the need for “context-specific prevention strategies”, such as strict tobacco control measures, alcohol regulation and vaccination against HPV and other carcinogenic infections such as hepatitis B.
Improving air quality, safer workplaces, healthier diets and promoting physical activity are also important.
Furthermore, “coordinated action across sectors, from health and education to energy, transport and work, can save millions of families from the burden of a cancer diagnosis,” WHO said.
The UN agency highlighted that tackling preventable risk factors not only reduces the incidence of cancer, but also reduces long-term healthcare costs and improves the health and well-being of the population.
Listen to an interview with WHO Kenya on the national action plan to eliminate cervical cancer by 2030:
