A new study published in The Lancet Oncology has found that 12 infectious agents were responsible for around 12% of all new cancer cases worldwide in 2024, accounting for 2.3 million diagnoses - or 1 in every 8 cancers globally. The comprehensive global analysis, conducted by the World Health Organization's International Agency for Research on Cancer (IARC), evaluated 12 specific pathogens classified as Group 1 human carcinogens.
Researchers emphasized that while the vast majority of infected individuals never develop cancer, many of these pathogen-driven cases are entirely preventable through existing vaccines, antibiotics, and antiviral treatments. The study highlights the critical importance of scaling up global public health interventions, particularly in low- and middle-income regions where access to preventative healthcare remains limited.
Among the leading infectious drivers identified in the report are human papillomavirus (HPV), Helicobacter pylori, and Hepatitis B and C viruses, which together account for the overwhelming majority of infection-linked malignancies. HPV remains the primary culprit behind cervical cancer and several other anogenital and head-and-neck cancers, making widespread vaccination campaigns among adolescents a paramount public health priority.
Meanwhile, Helicobacter pylori, a common bacterial infection of the stomach, continues to be the primary risk factor for gastric cancer, often treatable with targeted antibiotic regimens if detected early. Hepatitis B and C chronic infections remain major contributors to hepatocellular carcinoma, the most common form of liver cancer, though effective antiviral therapies and birth-dose vaccines have begun to curb incidence rates.
Other pathogens on the monitored list include Epstein-Barr virus, human immunodeficiency virus (HIV), and various schistosome parasites, each linked to distinct types of lymphomas, sarcomas, and carcinomas. Public health experts hope this definitive list will prompt governments and international health agencies to redouble efforts in screening, early detection, and expanding vaccination coverage to save millions of lives.