Global study: 1 in 8 cancer cases caused by infection
A global study by the World Health Organization finds that approximately 12% of cancer cases (2.3 million new cases) were caused by infections in 2024. The main culprits: Helicobacter pylori, HPV, hepatitis B and C. The good news: many cases are preventable through vaccines and early treatment.
A major new global study by the World Health Organization (WHO), published in The Lancet Oncology, reveals that about 12% of all cancers diagnosed worldwide in 2024 were caused by infection. This amounts to 2.3 million new cases directly linked to various pathogens. Researchers identified five main infectious agents: Helicobacter pylori (responsible for about 4% of cases), human papillomavirus (HPV, also 4%), hepatitis B virus, Epstein-Barr virus, and hepatitis C virus. These infections can cause more than 20 types of cancer, including stomach, liver, blood, and cervical cancer. The study explains that viruses can alter the genes of the host cell, while bacteria and parasites cause chronic inflammation leading to DNA damage. The key message is that many of these cancers are preventable. A notable example is the HPV vaccine, which has led to a 90% drop in infections in Australia, putting it on track to eliminate cervical cancer by 2035. The study highlights a significant global gap: about 75% of infection-related cancers occur in low- and middle-income countries, where access to vaccines and treatments is limited.