Analysis Links 2.3 Million New Cancer Cases to Preventable Infections

What the analysis measured

Researchers used global cancer data to estimate the number of new cancer cases in 2024 that could be attributed to 12 infectious agents known to cause cancer in humans. The estimate—2.3 million cases—represents a population-level attribution, not proof that an infection directly caused every individual cancer in the dataset.

The team examined bacteria, viruses, and parasites and reported results by country, sex, age, and world region.

Which infections matter most

Five pathogens accounted for the majority of infection-linked cancers:

• Helicobacter pylori: mainly linked to stomach cancer.
• Human papillomavirus (HPV): responsible for nearly all cervical cancer plus some cancers of the anus, penis, and throat.
• Hepatitis B virus (HBV) and hepatitis C virus (HCV): primarily associated with liver cancer.
• Epstein-Barr virus (EBV): contributes mainly to nasopharyngeal cancer.

Other infectious agents were included in the analysis, but these five drove the largest share of cases.

Who is most affected

The burden of infection-attributable cancers is not evenly distributed. Eastern Asia had the largest share of such cases, and about 75% of them occurred in low- and middle-income countries. The analysis also broke down differences by sex and age, reflecting how exposure, access to prevention, and screening vary across populations.

Why infections can lead to cancer

An infection does not automatically cause cancer. The risk grows when certain infections persist over years. Long-term H. pylori infection can create chronic stomach inflammation that gradually promotes cancerous changes. Persistent HPV, HBV, or HCV infections can cause ongoing tissue damage or immune changes that raise cancer risk. The population-attributable estimates use established evidence linking these infections to later cancer development.

Practical steps to lower your risk

You don't need to overhaul your health routine. Concrete preventive actions include:

• Check vaccine status: HPV and hepatitis B vaccines prevent infections tied to several cancers. Ask a clinician if you or your family members need vaccination or additional doses.
• Keep up with screening: Routine cervical screening detects HPV-related precancerous changes before they become cancer. Based on risk factors or regional guidance, testing for H. pylori, HBV, or HCV may be appropriate.
• Ask about testing and treatment: If you have risk factors, symptoms, or unclear testing history, raise it with your provider. Some infections can be treated or managed, which can reduce long-term cancer risk.

What this means for prevention strategies

The analysis frames a practical way to reduce a sizeable share of global cancer cases: prevent the infections that begin the pathway. Vaccination programs, accessible screening, and affordable testing and treatment can reduce future cancer burden, particularly where infection-linked cancers are concentrated.

Bottom line

About 1 in 8 new cancers worldwide in 2024 were estimated to be related to preventable or treatable infections. Individual prevention choices—vaccination, screening, and timely care—intersect with public-health actions to reduce that burden, especially in regions with higher infection-linked cancer rates.