RESEARCHERS LINK ONE IN EIGHT CANCERS TO INFECTIONS WORLDWIDE

About 2.3 million new cancer cases worldwide in 2024 were linked to infections, roughly one in eight of the total, according to a global review published in The Lancet Oncology. The research, led by Harriet Rumgay and reviewed by the International Agency for Research on Cancer, identified around a dozen infectious agents linked to cancer. Five accounted for almost all of the infection-linked cases: Helicobacter pylori, human papillomavirus (HPV), hepatitis B virus, Epstein-Barr virus and hepatitis C virus. H. pylori, a stomach bacterium, was linked to the most cases, at 760,000, followed by the sexually transmitted HPV virus at 750,000.

Hepatitis B virus was linked to 2% of global cancer cases, Epstein-Barr virus to 1% and hepatitis C virus to less than 1%, the study found. Epstein-Barr virus, spread through saliva, was linked to about 260,000 cases, mostly nasopharyngeal cancer, while hepatitis C virus, spread through infected blood, accounted for roughly 160,000. H. pylori was linked to stomach cancer, HPV to cervical cancer and both hepatitis viruses to liver cancer, researchers said. Dr Patrick Moore, of the University of Pittsburgh, said infection is "a much more important factor in cancer than most people recognise."

Researchers said most infection-related cancers can already be prevented through vaccination, condom use and screening, but noted barriers to access remain in many countries. The study's authors called for wider vaccination, testing for infectious agents and greater access to cancer screening. Rumgay and colleagues said the updated estimates "highlight the continued importance of infection control in global cancer prevention strategies." The findings add to existing evidence linking infections to cancer, researchers said, adding that further work is needed to reduce preventable cases.