Study: 12% of new cancer cases worldwide are associated with infections

About 12 percent of all new cancer cases worldwide are due to infections, the vast majority of which are caused by just five pathogens. In 2024, they were associated with approximately 2.3 million cancer cases. The results of the global study were published in The Lancet Oncology.

In first place was the bacterium Helicobacter pylori, which infects approximately half of the world's population. Researchers have linked about 760 thousand new cases of cancer per year to it - approximately four percent of all diagnosed cancers. The bacterium can cause chronic inflammation and damage to the stomach lining, increasing the risk of cancer.

Almost the same contribution was made by the human papillomavirus (HPV) - about 750 thousand cases. Some of its types can cause cervical cancer, as well as a number of other malignant tumors.

Another two percent of cancer cases were associated with the hepatitis B virus. The top five pathogens also included the Epstein-Barr virus and the hepatitis C virus. The latter, like hepatitis B, can cause chronic liver damage and increase the risk of cancer of this organ.

The proportion of infection-related tumors is particularly high in low- and middle-income countries, accounting for about three quarters of such cases. The highest numbers were reported in East Asia.

The authors emphasize that a significant proportion of these cancers are potentially preventable. Vaccines are available for HPV and hepatitis B, and H. pylori can be detected and treated. Therefore, prevention and timely treatment of infections can simultaneously reduce the risk of developing certain types of cancer.