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.
This accounts for 2.3 million diagnoses, or 1 in every 8 cancers globally.
The analysis, conducted by the World Health Organization’s International Agency for Research on Cancer (IARC), evaluated 12 pathogens classified as Group 1 human carcinogens.
Here’s full list:
- Helicobacter pylori: 760,000 cases (4% of all cancers). A stomach bacterium transmitted through contaminated food and water leading to non-cardia gastric cancer.
- Human Papillomavirus (HPV): 750,000 cases (4%). The primary driver of cervical cancer, plus oropharyngeal, anal, penile, vaginal, and vulvar cancers.
- Hepatitis B Virus (HBV): 360,000 cases (2%). Contracted through blood, sexual contact, and mother-to-child transmission causing liver cancer.
- Epstein-Barr Virus (EBV): 260,000 CASES (1%). A ubiquitous herpesvirus carried by over 90% of adults. Linked to nasopharyngeal carcinoma, gastric adenocarcinoma, and lymphomas.
- Hepatitis C Virus (HCV): 160,000 cases. A bloodborne virus causing chronic hepatitis and liver cancer.
- Kaposi’s Sarcoma-Associated Herpesvirus (KSHV): 35,000 cases. Causes Kaposi’s sarcoma.
- Human T-cell Lymphotropic Virus Type 1 (HTLV-1): 3,900 cases. Causes adult T-cell leukemia/lymphoma.
- Schistosoma haematobium: 5,900 cases. A parasitic flatworm causing bladder cancer.
- Opisthorchis viverrini: Liver fluke causing bile duct cancer.
- Clonorchis sinensis: Liver fluke causing bile duct cancer.
- Merkel Cell Polyomavirus: 3,200 cases. Causes aggressive Merkel cell skin carcinoma.
- HIV: 2,300 direct cases, plus tens of thousands indirectly through immune suppression.
Researchers emphasized that most infected people never develop cancer, and many of these cancers are preventable through vaccines, antibiotics, and antiviral treatments.
