One in eight cancers worldwide linked to infections, WHO study finds
WHO/IARC researchers report that 2.3 million cancer cases in 2024 — about 12% — were caused by infections, with five pathogens behind almost all of them.
Around one in eight cancers diagnosed worldwide in 2024 were caused by infections, according to new research from the World Health Organization (WHO) published today in The Lancet Oncology.
The study, led by Dr Harriet Rumgay of the Cancer Surveillance Branch at the International Agency for Research on Cancer in Lyon, estimated that 2.3 million new cancer cases globally in 2024 — 12% of all cancers diagnosed that year — were attributable to infections.
Of 12 pathogens assessed, five accounted for almost all infection-linked cases: Helicobacter pylori (760,000 cases, 4%), human papillomavirus (750,000, 4%), hepatitis B (360,000, 2%), Epstein-Barr virus (260,000, 1%) and hepatitis C (160,000, under 1%). The infections were linked to more than 20 cancer types, including stomach, liver, blood and cervical cancers.
The burden falls hardest on poorer nations: 77% of infection-linked cases were in low- and middle-income countries, with sub-Saharan Africa seeing the highest regional share at around a quarter of all cancers. The authors stress many of these cancers are preventable — through HPV and hepatitis B vaccination, testing and treatment for HIV, H. pylori and hepatitis B and C, and screening for precancerous lesions.
The researchers caution against comparing the 12% figure with earlier estimates from 1990–2018, saying changes in data sources and quality mean the comparisons cannot be made confidently.
Sources
More on this topic: all Health stories