Infection-Linked Cancer

Researchers estimate that infections are linked to roughly one in eight new cancer cases worldwide, amounting to millions of diagnoses. The burden is concentrated in cancers that can develop after long-lasting infections. Five pathogens account for most of these cases: human papillomavirus (HPV), hepatitis B and C viruses, Helicobacter pylori, and Epstein-Barr virus. They are associated with different cancers, including cervical and other HPV-related cancers, liver cancer, and stomach cancer. An infection does not mean cancer is inevitable; it can raise risk over time, and the likelihood varies with the pathogen, a person’s health and access to care.

The findings put prevention at the center of the response. Vaccines against HPV and hepatitis B can prevent infections that contribute to cancer, while screening can identify precancerous changes or disease earlier. Testing and effective treatment for hepatitis viruses, along with diagnosis and treatment of H. pylori, can also reduce some infection-related risks. Experts say these tools are not equally available worldwide: vaccination coverage, screening programs and access to treatment vary substantially, particularly in regions with high rates of related cancers. The scale of the burden therefore represents both a public-health challenge and an opportunity. Expanding proven prevention and care could avert cases, but progress depends on reaching people who currently lack those services.