Infections drove about 2.3 million new cancer cases worldwide in 2024, one in eight diagnoses, and doctors say many of those cancers were preventable.
A new analysis from the International Agency for Research on Cancer tied a substantial share of global cancer diagnoses to a short list of known infectious agents, Fox News Digital reported.
The findings, published Sept. 28 in The Lancet Oncology, used 2024 cancer data and estimated that infections were linked to roughly one in eight new cases worldwide. Researchers identified 12 infections already proven to cause cancer in humans.
Five of those infections accounted for nearly all of the global total. Helicobacter pylori was tied to about 760,000 cases. Human papillomavirus was linked to about 750,000. Hepatitis B contributed roughly 360,000, Epstein, Barr virus about 260,000, and hepatitis C about 160,000.
The remaining agents on the list included Kaposi sarcoma-associated herpesvirus, Schistosoma haematobium, HTLV-1, Opisthorchis viverrini, Clonorchis sinensis, Merkel cell polyomavirus, and HIV. The study was conducted in France and relied on population-level estimates rather than long-term tracking of individual patients. Results depended on the quality of cancer data available in each country. Because the analysis included only infections already proven to cause cancer, researchers noted the true toll could be higher.
Study co-author Dr. Harriet Rumgay, a scientist in IARC’s Cancer Surveillance Branch, stressed prevention in a press release.
"The findings underscore the major role that infection control can play in reducing the global cancer burden."
Rumgay also pointed to unequal impact.
"Despite progress in vaccination and screening, infection-related cancers remain a major global challenge, with the burden falling disproportionately on populations in low- and middle-income countries."
Researchers said many of these cancers could have been prevented through vaccination, treatment, or screenings. That is the practical takeaway for patients and clinicians alike.
Dr. Joshua Cohen, medical director of the Gynecologic Cancer Program at City of Hope Orange County in Irvine, California, reviewed the findings for Fox News Digital. He was not involved in the study.
"We know that there are certain infections that we are exposed to over our lifetime that may result in an increased risk of certain cancers."
He drew a clear line that often gets lost in headlines.
"However, most cancers are not caused by infection."
Cohen said the vast majority of people who carry HPV, H. pylori, or even hepatitis B or C will never develop cancer. The clinical job, he said, is to reduce risk for those who do carry one of these infections and to keep patients safe with the tools already available.
Cohen focused heavily on human papillomavirus, which ranked near the top of the case counts.
"Eighty percent of the population has been exposed to certain types of HPV strains."
He said about 40,000 people in the United States are diagnosed each year with HPV-related cancers along the rectum, vagina, or cervix, as well as cancers of the oropharynx. Doctors still cannot fully explain why some patients’ immune systems clear the virus and others do not.
For younger adults, he was direct about vaccination.
"If you’re under the age of 45 and you've not had an HPV vaccination, there is various good safety data that you should get vaccinated."
That shot, he said, covers most U.S. risks for oropharyngeal, vaginal, cervical, penile, and anal cancers.
Cohen also addressed the stomach bacterium that led the global case list.
"We don't screen everybody for H. pylori in the U.S., it's more common in other parts of the world, like Southeast Asia."
He advised patients with peptic ulcer disease or significant upper abdominal pain to discuss testing and treatment with their doctors. The point was not panic. It was practical risk reduction for people who already have symptoms or known infection.
His broader counsel to patients was straightforward.
"As a patient, the most important thing is to think about your health, what you can do to prevent yourself from developing these infections or your family."
And if infection is already present:
"And if you do have one of these infections, what can you do to reduce your risk of developing a subsequent cancer?"
Cohen closed on the same theme that runs through the IARC numbers: doctors have steps that can lower cancer risk after infection, and patients who act on vaccination, screening, and treatment are not waiting on chance.
The data put a hard number on a preventable slice of the global cancer load. Personal habits, proven shots, and timely treatment still matter more than fatalism.
