The study by the United Nations World Health Organization (WHO) and its International Agency for Research on Cancer (IARC) looks at 30 preventable causes, including tobacco, alcohol, high body mass index, physical inactivity, air pollution and ultraviolet radiation.
Nine cancer-causing infections – such as human papillomavirus (HPV), which can cause cervical cancer – are also included for the first time.
Examining patterns of prevention
Cancer remains a leading cause of morbidity, responsible for nearly 10 million deaths worldwide in 2020, or nearly one in six.
Projections point to a 50 percent increase in new cases by 2040 if current trends continue, underscoring the urgent need for effective prevention strategies.
The study was released ahead of World Cancer Day, which is observed annually on February 4.
The results draw on data from 185 countries and 36 cancer types. It shows discretion 37 percent of all new cancer cases in 2022, about 7.1 million, were linked to preventable causes.
“By examining patterns across countries and population groups, we can provide governments and individuals with more specific information to help prevent many cancers before they start,” said Dr. André Ilbawi, WHO team leader for cancer control and author of the study.
Tobacco top case
Tobacco is the leading preventable cause of cancer, responsible for 15 percent of all new casesfollowed by infections (10 per cent) and alcohol consumption (3 per cent).
Lung, stomach and cervical cancer represented almost half of all preventable cases in both men and women.
Lung cancer was primarily linked to smoking and air pollution, while stomach cancer was largely caused Helicobacter pylori infection. Cervical cancer was predominantly caused by HPV.
Differences between men and women
The burden of preventable cancer was significantly higher in men than in women. Among new cancer cases, 45 percent occur in men against 30 percent in women.
In men, smoking accounted for an estimated 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 picture, risk factors
Preventable cancers also varied greatly between regions of the world.
Among women, they ranged 24 percent in North Africa and West Asia, to 38 percent in sub-Saharan Africa.
Among men, East Asia accounted for the highest burden with 57 per centwhile the lowest incidence was found in Latin America and the Caribbean at 28 per cent.
These differences are largely due to varying exposure to behavioral, environmental, occupational, and infectious risk factors, as well as differences in socioeconomic development, national prevention policies, and health system capacity.
Prevention strategies
The report emphasized the need for “context-specific prevention strategies” such as strong tobacco control measures, alcohol regulation and vaccination against HPV and other cancer-causing infections such as hepatitis B.
Improved air quality, safer workplaces, healthier food and promotion of physical activity are also important.
Moreover, “coordinated effort across sectors, from health and education to energy, transport and labour, can prevent millions of families from experiencing the burden of a cancer diagnosis,” WHO said.
The UN agency emphasized that treating preventable risk factors not only reduces cancer incidence, but also lowers long-term health care costs and improves population health and well-being.
Listen to an interview with WHO Kenya on the national action plan to eliminate cervical cancer by 2030:
