Infections Linked to One in Eight New Cancer Cases Worldwide in 2024
A WHO analysis found that 12% of global cancer cases in 2024 were attributable to twelve infectious agents, with Helicobacter pylori and human papillomavirus accounting for the largest shares.
Researchers from the World Health Organization have estimated that infectious diseases were responsible for about 2.3 million cancer cases, or roughly one in eight, worldwide in 2024. The assessment covered twelve pathogens, including viruses such as HPV, HIV, hepatitis B and C, Epstein-Barr virus, Kaposi’s sarcoma-associated herpesvirus, human T-cell lymphotropic virus type 1 and Merkel cell polyomavirus, the bacterium Helicobacter pylori, and three parasitic fluke worms.
The analysis, published in The Lancet Oncology, identified H. pylori as the leading cause with approximately 760,000 stomach cancer cases, followed closely by HPV with about 750,000 cases, primarily cervical cancer. Hepatitis B and C together accounted for more than 400,000 liver cancer cases.
"The findings underscore the major role that infection control can play in reducing the global cancer burden," said Harriet Rumgay, a scientist with the International Agency for Research on Cancer.
The report notes that many of the implicated infections are preventable or treatable. Effective vaccines exist for HPV and hepatitis B, antibiotics can eradicate H. pylori, and modern antivirals cure hepatitis C in most patients. Pre-exposure prophylaxis and antiretroviral therapy substantially reduce HIV transmission. Antiparasitic drugs and improved sanitation can curb the fluke-related cancers.
Despite the availability of interventions, vaccination coverage for HPV remains lower in the United States than in several high-income nations, and hepatitis B vaccination rates face policy challenges. The study emphasizes that infection-related cancer burdens are disproportionately higher in low- and middle-income countries, highlighting the need for expanded prevention and treatment programs worldwide.