An international study has confirmed that infectious agents cause approximately 10.2% of all recent cancer cases globally, equating to 2.3 million diagnoses annually. The research, published in Nature Medicine and highlighted by the International Agency for Research on Cancer (IARC), identifies nine specific infectious agents – bacteria, viruses, and parasites – as significant contributors to cancer development.
The study marks the first integrated analysis to equate the cancer risk posed by these infections with that of more commonly recognized risk factors like smoking and alcohol consumption. Researchers found that infections can trigger cancers including stomach cancer, cervical cancer, liver cancer, bladder cancer, and bile duct cancer. The findings underscore the potential for cancer prevention through interventions such as vaccination, antibiotic treatment, and improved sanitation.
The nine identified infectious agents are Helicobacter pylori, Human Papillomavirus (HPV), Hepatitis B virus (HBV), Hepatitis C virus (HCV), Epstein-Barr virus (EBV), Human Herpesvirus 8 (HHV-8), Schistosoma species (blood flukes), Human T-lymphotropic virus type 1 (HTLV-1), and Opisthorchis species (liver flukes).
While preventative measures exist for many of these infections, access and public health infrastructure remain significant barriers to widespread implementation. According to the research, millions of cancer cases could be avoided each year with improved access to preventative care.
Hepatitis B virus (HBV) infection remains a substantial public health concern. The Korea Disease Control and Prevention Agency reports that while vaccination efforts have reduced the prevalence of HBV in South Korea, rates remain higher than in the United States and many European countries. Acute HBV infection can progress to chronic infection in 5-10% of cases, potentially leading to cirrhosis or liver cancer.
Helicobacter pylori, HBV, and HPV were specifically identified as major contributors to cancers of the stomach, liver, and cervix, respectively. A report from the Cancer Answer website notes that these pathogens are well-known causes of these specific cancers.
The study estimates that in 2025, infections will be responsible for 9.35% of all cancer cases and 10.18% of cancer-related deaths. The researchers predict that infections will continue to contribute to over 10% of all cancer cases through 2030.
