A recent study published in The Lancet Oncology reveals that infections play a significant role in cancer development, accounting for one in eight new cancer cases globally. The research, conducted by The International Agency for Research on Cancer (IARC), identified infectious agents as the cause of an estimated 2.3 million new cancer cases in 2024, representing 12% of all new cases.
Among the infectious agents, Helicobacter pylori, a bacterium linked to stomach cancer, was responsible for the highest number of cases globally, particularly in eastern Asia. Human papillomavirus (HPV) closely followed, causing various cancers including cervical cancer, with substantial impact in sub-Saharan Africa. Hepatitis B virus (HBV) and hepatitis C virus (HCV) were also associated with a significant number of liver cancer cases.
The study expanded the list of cancers linked to infections, identifying 16 additional types. Notably, new infectious agents like HIV and Merkel cell polyomavirus were found to contribute to certain cancers. Epstein-Barr virus (EBV) was recognized as a key player in cancer development, particularly in nasopharyngeal cancer and Hodgkin’s lymphoma.
Researchers highlighted regional disparities in cancer cases due to historical factors. High-income countries with established screening and vaccination programs have lower infection-related cancer rates compared to countries with limited access to prevention and treatment. In Canada, infections account for about four percent of cancer cases, with HPV being a significant concern despite lower prevalence rates.
Efforts to combat infection-related cancers in Canada include increasing vaccination and screening rates. Cervical cancer, primarily caused by HPV, has seen declining rates due to vaccination programs, but recent plateaus raise concerns about meeting elimination goals by 2040. Screening programs for high-risk groups, such as those with a family history of stomach cancer, are crucial for early detection and prevention.
Leading researchers emphasize the importance of universal screening programs for infections like Helicobacter pylori to prevent avoidable deaths from stomach cancer. While the impact of infections on cancer varies globally, targeted interventions and increased awareness can help reduce the burden of infection-related cancers worldwide.
