A recent study published in The Lancet Oncology reveals that infections play a significant role in causing cancer, contributing to one in eight new cancer cases globally in 2024. The research, conducted by The International Agency for Research on Cancer (IARC), identified various viruses, bacteria, and other microbes as culprits behind approximately 2.3 million new cancer diagnoses.
Among the infectious agents, Helicobacter pylori was found to be the leading cause, responsible for 760,000 cases of stomach cancer, particularly prevalent in eastern Asia. Human papillomavirus (HPV) followed closely behind, accounting for nearly 750,000 new cases worldwide, with high incidences in sub-Saharan Africa. Additionally, hepatitis B virus (HBV) and hepatitis C virus (HCV) were associated with a considerable number of liver cancer cases.
The study expanded the list of cancers linked to infections, identifying 16 additional types. Notable findings included the association of HIV with cervical cancer and Merkel cell polyomavirus with an aggressive form of skin cancer.
Epstein-Barr virus (EBV) was also recognized as a significant contributor to cancer, with an estimated 260,000 cases globally in 2024, causing nasopharyngeal cancer, gastric cancers, and Hodgkin’s lymphoma. EBV has been linked to multiple sclerosis as well, posing challenges due to the lack of available treatments.
The researchers emphasized regional disparities in cancer burden, with high-income countries showing better outcomes due to established screening and vaccination programs. In North America, Helicobacter pylori and HPV were identified as the primary sources of cancer-causing infections.
In Canada, infections were estimated to contribute to four percent of cancer cases, leading to over 7,000 diagnoses annually. HPV remains a key concern, prompting efforts to increase vaccination rates and screening to combat cervical cancer effectively.
Dr. Paul Moayyedi from McMaster University highlighted the impact of Helicobacter pylori in causing stomach cancer, advocating for universal screening programs to detect and treat the bacterium promptly. He emphasized the importance of targeted screenings for high-risk groups, such as those with a family history of stomach cancers or specific communities, to prevent unnecessary cancer-related deaths.
The study underscores the critical role infections play in cancer development and the importance of preventive measures and early detection strategies to reduce the global cancer burden.
