About one in eight cancers worldwide can be traced to infections. The finding comes from a new study in The Lancet Oncology.

Researchers found 2.3 million new cancer cases in 2024 were linked to 12 infections. That is 12 percent of all cancer diagnoses that year.

Five infections caused almost all of them. H. pylori, a stomach bacterium, was linked to 760,000 cases. HPV was tied to 750,000 cases, mostly cervical cancer.

Hepatitis B caused 360,000 liver cancers. Epstein-Barr virus was linked to 260,000 cases. Hepatitis C caused 160,000.

Researchers from the International Agency for Research on Cancer led the work. Senior author Gary Clifford said prevention works.

HPV and hepatitis B vaccines can cut risk. Screening and treatment help too. Low and middle-income countries carry 77 percent of the burden.

The study shows that millions of cancers could be prevented with tools we already have. Prevention remains the most powerful tool, the authors said.

Sources:

• https://www.usatoday.com/story/news/health/2026/10/05/infections-behind-1-in-8-cancer-cases-hpv-h-pylori/92107065007/
• https://www.cnn.com/2026/10/05/health/cancer-cases-caused-by-infection-study-wellness?cid=external-feeds_iluminar_meta
• https://medicaldialogues.in/mdtv/oncology/videos/can-infections-cause-cancer-lancet-study-links-1-in-8-cancer-cases-to-infections-180459