A recent study has revealed that infections are responsible for a significant percentage of cancer cases worldwide. Published in The Lancet Oncology, the research conducted by The International Agency for Research on Cancer (IARC) found that approximately 12% of all new cancer cases in 2024, totaling 2.3 million cases, were linked to various infectious agents such as viruses and bacteria.
The bacterium Helicobacter pylori was identified as the leading cause of cancer cases attributed to infections globally, particularly in eastern Asia, where it significantly increased the risk of stomach cancer, resulting in 760,000 cases. Human papillomavirus (HPV) followed closely behind, being responsible for nearly 750,000 new cancer cases worldwide, with high prevalence in sub-Saharan Africa. Hepatitis B virus (HBV) and hepatitis C virus (HCV) were also associated with a considerable number of liver cancer cases.
Researchers expanded the list of cancers linked to infections, identifying 16 additional types for the first time. Notably, new infectious agents like HIV were found to be linked to cervical cancer, while a rare virus called Merkel cell polyomavirus was associated with an aggressive form of skin cancer.
Epstein-Barr virus (EBV) was recognized as a key contributor to cancer cases globally, with approximately 260,000 cases in 2024, leading to nasopharyngeal cancer, certain gastric cancers, and Hodgkin’s lymphoma. This virus was also highlighted for its role in other chronic diseases like multiple sclerosis, underscoring the need for preventive measures.
The study emphasized significant regional disparities in cancer cases attributed to infections, with high-income countries having better outcomes due to established screening and vaccination programs. In Canada, infections were estimated to contribute to about 4% of cancer cases, leading to over 7,000 cancer diagnoses annually. While the prevalence of these infections is lower in Canada, efforts to increase vaccination rates and screening remain crucial to combat diseases like cervical cancer caused by HPV.
Dr. Paul Moayyedi from McMaster University emphasized the importance of screening for Helicobacter pylori, which can lead to stomach cancer if left untreated. He advocated for universal screening programs, particularly for high-risk groups, to prevent avoidable deaths. The study shed light on the critical role of infections in cancer development and the necessity of proactive measures to reduce the burden of infection-related cancers globally.
