A recent study published in The Lancet Oncology reveals that infections play a more significant role in causing cancer than previously thought. Researchers at The International Agency for Research on Cancer (IARC) found that approximately one in eight cancer cases worldwide in 2024, totaling 2.3 million cases, were attributed to various infectious agents.
The bacterium Helicobacter pylori was identified as the leading cause of cancer cases globally, particularly in eastern Asia, contributing to 760,000 cases of stomach cancer. Human papillomavirus (HPV) followed closely behind, 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 linked to a significant number of liver cancer cases.
Furthermore, the study identified 16 additional cancers associated with infections for the first time, showcasing the evolving understanding of infectious agents’ impact on cancer development. Researchers highlighted the growing evidence of various infections like HIV and Merkel cell polyomavirus causing specific types of cancer.
Epstein-Barr virus (EBV) was newly recognized as a significant contributor to cancer cases globally, linked to diseases such as nasopharyngeal cancer, some gastric cancers, and Hodgkin’s lymphoma. The study emphasized the importance of addressing infections like EBV, which have no available preventive tools, in combating cancer-related health challenges.
The research noted considerable regional disparities in cancer incidence related to infections, with high-income countries benefiting from established screening and vaccination programs. In contrast, lower- and medium-resourced countries face limitations in accessing preventive measures and treatment.
In Canada, a 2019 study estimated that four percent of cancer cases were attributable to infections, with over 7,000 cancer diagnoses annually. While the prevalence of infection-related cancers is lower in Canada, experts emphasize the importance of continuous monitoring and preventive measures, particularly for infections like HPV, to reduce cancer burden.
Efforts to combat infections causing cancer in Canada include enhancing vaccination and screening programs, aiming to achieve high vaccination and screening rates to eliminate cervical cancer by 2040. Experts stress the need for increased awareness and access to preventive measures to address the persistent challenges posed by infection-related cancers.
Dr. Paul Moayyedi, a leading gastroenterologist, highlighted the significance of screening programs for Helicobacter pylori, emphasizing the importance of early detection and treatment to prevent stomach cancer. He advocated for targeted screening initiatives for high-risk populations to improve cancer outcomes and save lives.