A recent study published in The Lancet Oncology reveals that infections play a larger role in causing cancer than previously thought. The research, conducted by The International Agency for Research on Cancer (IARC), a division of the World Health Organization, found that approximately 12% of new cancer cases worldwide in 2024 were linked to various infectious agents.
Among the infectious agents identified, Helicobacter pylori was responsible for a significant number of cases, particularly in eastern Asia, where it is associated with an increased risk of stomach cancer. Human papillomavirus (HPV) was another prominent culprit, causing a considerable number of cases globally, including cervical cancer and other related cancers, with higher rates in sub-Saharan Africa.
The study also highlighted the role of hepatitis B virus (HBV), hepatitis C virus (HCV), and Epstein-Barr virus (EBV) in contributing to liver cancer and other types of cancer. In addition, researchers expanded the list to include 16 more types of cancer linked to infections, such as HIV and Merkel cell polyomavirus.
The findings underscore the need for increased awareness of the impact of infections on cancer development. The research points to regional disparities in cancer rates, with high-income countries benefiting from established screening and vaccination programs, while lower-resource countries face challenges in access to prevention and treatment.
In Canada, a 2019 study estimated that infections contribute to about 4% of cancer cases, leading to over 7,000 new cancer diagnoses annually. Efforts to combat infections like HPV through vaccination programs have shown success in reducing cervical cancer rates, although recent plateaus in progress raise concerns about meeting elimination targets.
Experts emphasize the importance of continued efforts to increase vaccination and screening rates to prevent cancer caused by infectious agents. In particular, promoting screening programs for infections like Helicobacter pylori could help identify individuals at high risk and potentially save lives by addressing these preventable causes of cancer.