One in eight cancers are likely caused by an infection worldwide – new study

# Infections Drive 12% of Global Cancer Cases—Many Are Preventable

Infections caused roughly one in eight cancer diagnoses worldwide in 2024, according to new research. Four viruses and one bacterium together account for 12 percent of all cancer cases globally. This finding underscores a reality that distinguishes cancer from other diseases: many of these infection-linked cancers can be prevented through existing vaccines and medical interventions.

The infectious agents responsible are human papillomavirus (HPV), hepatitis B virus (HBV), hepatitis C virus (HCV), Epstein-Barr virus (EBV), and Helicobacter pylori bacteria. HPV stands out as the leading infection-related cancer cause, driving cervical, anal, and throat cancers. HBV and HCV together fuel hepatocellular carcinoma, the most common form of liver cancer. EBV connects to certain lymphomas and nasopharyngeal cancers. H. pylori increases stomach cancer risk through chronic inflammation.

The geographic distribution matters. High-income countries report lower infection-related cancer rates because vaccines and screening programs reach broader populations. Hepatitis B vaccination, rolled out in many developed nations decades ago, has dramatically cut childhood infection rates and subsequent liver cancer risk. HPV vaccination programs in countries like Australia, the United States, and much of Europe have already reduced cervical cancer incidence.

Developing regions carry a disproportionate burden. Sub-Saharan Africa, Southeast Asia, and parts of South America face higher prevalence of HBV and HCV due to limited vaccine access and screening capacity. This gap in prevention infrastructure creates a stark health equity issue. A person born in a low-resource setting faces substantially higher cancer risk from the same infectious agents that pose minimal threat to vaccinated populations elsewhere.

Prevention pathways exist for most of these infections. HPV vaccination, when given before sexual exposure, prevents infection entirely. Hepatitis B vaccine provides long-term immunity. Screening and treatment for H. pylori can eliminate cancer risk before tumors develop. Antiviral drugs for HCV cure the infection in over 95 percent of cases when people access treatment. Yet access remains uneven.

The research has direct implications for public health policy. Global health organizations, including the World Health Organization, have called for expanded vaccination programs in middle and low-income countries. Some barriers are logistical: cold-chain requirements, healthcare infrastructure gaps, and competing health priorities. Others are economic: vaccine costs, though dropping, still strain budgets in poorer nations.

For educators and health communicators, the findings reinforce a straightforward message: infection-related cancers differ from many others because prevention tools exist. Parents can protect children through HPV vaccination starting at age 11 or 12. Adults can test for and treat H. pylori. Screening programs can identify HBV and HCV before cancer develops.

The 12 percent figure should prompt reflection on health equity. Cancer prevention is not equally accessible globally. Closing vaccination gaps and expanding screening access in underserved regions would prevent millions of cancers over coming decades. This is not speculative—it is achievable with political will and resource allocation.