Up to four in ten cancer cases worldwide could be prevented, a new global analysis has found.
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 infections that can cause the disease.
Released ahead of World Cancer Day on 4 February, the analysis from the World Health Organization (WHO) and its International Agency for Research on Cancer (IARC) estimates that 37 per cent of all new cancer cases in 2022, around 7.1 million cases, were linked to preventable causes.
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 per cent of all new cancer cases, followed by infections (10 per cent) and alcohol consumption (3 per cent).
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 (a bacterial infection of the stomach lining), and cervical cancer was overwhelmingly caused by human papillomavirus (HPV).
Dr André Ilbawi, team lead for cancer control at WHO and author of the study, said: “This is the first global analysis to show how much cancer risk comes from causes we can prevent.
“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 substantially higher in men than in women, with 45 per cent of new cancer cases in men compared with 30 per cent in women.
In men, smoking accounted for an estimated 23 per cent of all new cancer cases, followed by infections at 9 per cent and alcohol at 4 per cent.
Among women globally, infections accounted for 11 per cent of all new cancer cases, followed by smoking at 6 per cent and high body mass index at 3 per cent.
Dr Isabelle Soerjomataram, deputy head of the IARC Cancer Surveillance Unit and senior author of the study, said: “This landmark study is a comprehensive assessment of preventable cancer worldwide, incorporating for the first time infectious causes of cancer alongside behavioural, environmental and occupational risks.
“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 per cent in North Africa and West Asia to 38 per cent in sub-Saharan Africa.
Among men, the highest burden was observed in East Asia at 57 per cent, and the lowest in Latin America and the Caribbean at 28 per cent.
These differences reflect varying exposure to behavioural, environmental, occupational and infectious risk factors, as well as differences in socioeconomic development, national prevention policies and health system capacity.
