An estimated 12% of global cancer cases in 2024—2.3 million diagnoses—were caused by infections, according to a study by the International Agency for Research on Cancer (IARC). The research highlights the preventability of many of these cancers through vaccination, screening, and treatment, while underscoring stark regional disparities in infection-linked cancer burdens.
The study, published in The Lancet Oncology on September 28, 2026, was led by Harriet Rumgay and colleagues at IARC. It analyzed data from the IARC Global Cancer Observatory and identified five pathogens responsible for the majority of infection-linked cancers: Helicobacter pylori (760,000 cases), human papillomavirus (HPV) (750,000 cases), hepatitis B virus (HBV) (360,000 cases), Epstein-Barr virus (EBV) (260,000 cases), and hepatitis C virus (HCV) (160,000 cases). These infections were linked to over 20 cancer types, including cervical, stomach, liver, and lymphatic cancers.
One in eight cancers worldwide linked to infections
Dr. Patrick Moore, chair in Innovative Cancer Research at the University of Pittsburgh, emphasized that the findings suggest a significant proportion of the global cancer burden is preventable through better infection control.
He noted that the IARC’s estimates may be very conservative,
stating that the actual fraction of cancers caused by infection is likely to be still larger.
Moore also warned that cuts to HIV treatment funding, such as those resulting from the disbanding of USAID, could increase infectious cancers in sub-Saharan Africa.
We can test for them.
Regional disparities in infection-linked cancer burdens were stark. The study found that a significant portion of infection-related cancer diagnoses occurred in Eastern Asia, with sub-Saharan Africa and South-East Asia also bearing heavy burdens.
1 in 8 Cancer Cases Worldwide Linked to Infections
The research builds on three decades of work by the study’s authors, who have examined infection-linked cancers in 1990, 2002, 2008, 2012, and 2018. While the proportion of cancer cases attributed to infections appeared to decline from 18% in 2002, the authors cautioned that data quality and sources have evolved, making direct comparisons unreliable. The 2026 study aimed to highlight where controlling and preventing infections can help to reduce cancer,
according to the researchers.
Infections cause cancer through mechanisms such as chronic inflammation, DNA damage, and viral integration into host cells. Dr. Clifford explained that viruses hijack cellular machinery to aid their replication, often disrupting processes that normally repair DNA or trigger cell death. The study also highlighted the role of global health equity, noting that underfunded regions face higher burdens due to limited access to vaccines and screening programs.
Prevention strategies emphasized in the study include expanded vaccination programs, improved access to antiviral treatments, and targeted screening initiatives. Dr. Moore warned that expanded HBV vaccination in Asia could significantly reduce liver cancer rates, while cuts to HIV treatment in sub-Saharan Africa could worsen outcomes. The research also highlighted emerging links, such as EBV’s role in gastric cancer, which was recently established in the study.
The study’s findings reinforce the urgency of addressing regional health inequities.
For readers, the study confirms that many infection-linked cancers are preventable but does not provide individual medical advice. It calls for consulting qualified professionals to discuss personalized risk factors and prevention strategies.