Four in Ten Cancer Cases Are Preventable According to Study

Up to four in ten cancer cases worldwide could be prevented, according to a new global analysis from the World Health Organization (WHO) and its International Agency for Research on Cancer (IARC). The study examines 30 preventable causes, including tobacco, alcohol, high body mass index, physical inactivity, air pollution, ultraviolet radiation – and for the first time – nine cancer-causing infections.

Released ahead of World Cancer Day on February 4, the analysis estimates that 37% of all new cancer cases in 2022, approximately 7.1 million cases, were associated with preventable causes. The findings emphasize the significant potential of prevention in alleviating the global cancer burden.

Drawing on data from 185 countries and 36 cancer types, the study identifies tobacco as the leading preventable cause of cancer, globally responsible for 15% of all new cancer cases, followed by infections at 10% and alcohol consumption at 3%.

Three cancer types – lung, stomach, and cervical cancer – accounted for nearly half of all preventable cancer cases in both men and women globally.

Lung cancer was primarily linked to smoking and air pollution, stomach cancer was largely attributable to Helicobacter pylori infection, and cervical cancer was overwhelmingly caused by human papillomavirus (HPV).

"This is the first global analysis to show how much cancer risk comes from causes we can prevent,” said Dr. André Ilbawi, WHO Team Lead for Cancer Control and author of the study. “By examining patterns across countries and population groups, we can provide governments and individuals with more specific information to help prevent many cancer cases before they start.”

The burden of preventable cancer was significantly greater in men than in women, with men representing 45% of new cancer cases compared to 30% in women. In men, smoking was estimated to contribute to 23% of all new cancer cases, followed by infections at 9% and alcohol at 4%. Among women globally, infections accounted for 11% of all new cancer cases, followed by smoking at 6% and high body mass index at 3%.

"This landmark study is a comprehensive assessment of preventable cancer worldwide, incorporating for the first time infectious causes of cancer alongside behavioral, environmental, and occupational risks," said Dr. Isabelle Soerjomataram, Deputy Head of the IARC Cancer Surveillance Unit and senior author of the study. "Addressing these preventable causes represents one of the most powerful opportunities to reduce the global cancer burden."

Preventable cancer varied widely between regions. Among women, preventable cancers ranged from 24% in North Africa and West Asia to 38% in sub-Saharan Africa. Among men, the highest burden was observed in East Asia at 57%, and the lowest in Latin America and the Caribbean at 28%. These differences reflect varying exposure to behavioral, environmental, occupational, and infectious risk factors, as well as differences in socioeconomic development, national prevention policies, and health system capacity.

The findings highlight the necessity for prevention strategies tailored to specific contexts, which encompass robust tobacco control measures, regulations on alcohol, vaccination against cancer-related infections such as human papillomavirus (HPV) and hepatitis B, enhanced air quality, safer working conditions, and environments that promote healthier food choices and physical activity.

Coordinated action across sectors, from health and education to energy, transport, and labor, can prevent millions of families from enduring the strain of a cancer diagnosis. Tackling preventable risk factors not only decreases the incidence of cancer but also reduces long-term healthcare costs and enhances the health and well-being of the population.

Note to the editor:

WHO and its specialized cancer research agency IARC work together to enhance cancer prevention, early detection, treatment, and palliative care globally. They offer technical guidance, establish global and regional standards, and assist governments in improving access and reducing inequalities. Their efforts also encompass promoting research, formulating policies, and launching global initiatives focused on cervical, breast, and childhood cancers.