A recent study published in The Lancet Oncology reveals that infections are responsible for a significant proportion of cancer cases worldwide. Researchers at The International Agency for Research on Cancer (IARC) found that approximately one in eight new cancer cases in 2024, totaling 2.3 million cases, were linked to various infectious agents.
The bacterium Helicobacter pylori was identified as the leading cause of cancer cases globally, particularly stomach cancer in eastern Asia, contributing to 760,000 cases. Human papillomavirus (HPV) followed closely, accounting for almost 750,000 new cancer cases, predominantly in sub-Saharan Africa, including cervical cancer and other types of cancers. Hepatitis B and C viruses were also associated with a significant number of liver cancer cases.
Researchers expanded the list of cancers linked to infections, identifying 16 additional cancers, including some caused by HIV and Merkel cell polyomavirus. The study highlighted the role of Epstein-Barr virus (EBV) in causing nasopharyngeal cancer, gastric cancers, Hodgkin’s lymphoma, and its connection to multiple sclerosis.
The report emphasized regional disparities in cancer cases due to varying access to prevention and treatment. While high-income countries with established screening and vaccination programs have lower infection-related cancer burdens, lower resource countries face greater challenges.
In Canada, a study estimated that four percent of cancer cases are attributable to infections, with over 7,000 new cancer diagnoses annually. HPV remains a concern, with efforts to increase vaccination rates to combat cervical cancer. Despite declines in cervical cancer rates, plateauing trends raise concerns about achieving elimination goals without further interventions.
The bacterium Helicobacter pylori, a common cause of stomach cancer, poses a significant health risk globally. Screening programs are advocated to detect and treat infections early, potentially saving lives. While stomach cancers may not receive as much attention as other cancers, targeted screening for high-risk groups, such as those with a family history or specific communities, could be life-saving.
Overall, the study underscores the importance of understanding and addressing infection-related cancer risks to improve global cancer prevention and treatment strategies.