A new global analysis estimates that infections were responsible for about 2.3 million new cancer cases in 2024 — roughly 12% of all cancers diagnosed worldwide.
Remarkably, five pathogens accounted for nearly all of these infection-related cancers: Helicobacter pylori, human papillomavirus (HPV), hepatitis B virus (HBV), Epstein-Barr virus (EBV) and hepatitis C virus (HCV).
H. pylori alone was linked to around 760,000 cancer cases, mostly stomach cancer. The bacterium is extremely common — roughly half of the world’s population carries it — although most infected people never develop cancer.
HPV was linked to another 750,000 cases. Persistent infection with high-risk HPV types can cause cervical cancer as well as cancers of the throat, anus, penis, vulva and vagina. Vaccination can prevent infections responsible for many of these cancers.
Chronic hepatitis B and C infections can damage the liver over decades and increase the risk of liver cancer. EBV, which infects most humans at some point in their lives, is associated with several cancers including nasopharyngeal carcinoma and certain lymphomas.
The important part is that infection-related cancer is not inevitable. HPV and hepatitis B vaccines, hepatitis C treatment, H. pylori detection and treatment, screening and other public-health measures can prevent a significant number of cases.
About three-quarters of infection-related cancers occurred in low- and middle-income countries, showing how access to vaccination, testing and treatment can directly influence the global cancer burden.
Source: The Lancet Oncology; International Agency for Research on Cancer (IARC)