These 12 Infections Are Linked to Cancer—and Some Are Widespread
Guest Contributor
Infections and cancer may seem like separate health threats, but new research from the International Agency for Research on Cancer reveals just how closely they are intertwined. According to a global analysis of the cancer burden linked to infections in 2024, an estimated 2.3 million new cancer cases worldwide were caused by infectious agents. That means about one in eight new cancers can be traced back to an infection, a figure that reshapes how experts think about cancer prevention and control on a global scale and highlights the importance of understanding infection related cancers.
The study, published in The Lancet Oncology, represents the most comprehensive and up to date look so far at the global burden of cancer attributable to infections. Researchers used data from the IARC Global Cancer Observatory, a large international database that compiles cancer incidence figures from around the world. By mapping known links between specific infections and specific cancer types onto current cancer incidence data, they produced fresh estimates of how much of the worldwide cancer load is driven by infectious causes.
The analysis goes beyond earlier work in a few important ways. It includes additional infectious agents such as HIV and Merkel cell polyomavirus, reflecting advances in understanding how infections can disrupt normal cell growth. It also incorporates new evidence that broadens the list of cancers linked to already known carcinogenic infections. One example is the recent work connecting Epstein–Barr virus not only to established conditions such as certain lymphomas but also to gastric, or stomach, cancer.
This updated picture matters because it changes the scale and scope of what might be preventable. If around 12% of all new cancer cases in 2024 were caused by infections, then many of these cases could, in principle, be reduced through stronger infection control, wider use of vaccines, improved screening, and timely treatment of underlying infections. Even without adding any speculative numbers, the proportion alone underscores that infection prevention is also cancer prevention.
The researchers, led by Rumgay and colleagues, framed their work as a worldwide incidence analysis. Rather than focusing on one country or region, they examined patterns across the globe, using a standardized approach based on the IARC Global Cancer Observatory database. By grounding the study in this large and systematically collected dataset, they aimed to create a consistent global picture of cancers attributable to infections that can be compared over time as new data emerge.
Part of what makes this study stand out is the breadth of infectious agents considered. In addition to long recognized cancer causing infections, the analysis accounts for HIV and Merkel cell polyomavirus. HIV has long been associated with certain cancers such as Kaposi sarcoma and some lymphomas, through its effects on the immune system. Merkel cell polyomavirus has been implicated in Merkel cell carcinoma, a rare but aggressive skin cancer. Including these agents helps refine estimates of cancer incidence that can be traced back to infections, giving a more complete view of the overall burden.
The study also integrates newly established infection cancer associations. One highlighted development is the expanding evidence around Epstein–Barr virus. This virus has been linked to several cancers for years, but recent research has strengthened the association with gastric cancer, adding another major cancer type to the list of EBV related diseases. Accounting for this connection in global estimates shifts the numbers upward and emphasizes that the relationship between infections and cancer is still being clarified.
Although the article summarizing this work does not list every cancer type and every infectious agent in detail, the overarching message is clear. Cancer is not only a disease of genetics and lifestyle but, in a significant fraction of cases, also a consequence of infection. As understanding of carcinogenic infections expands, so does recognition of how prevention strategies targeted at infections may reduce cancer incidence.
One of the most practical implications of this research is its relevance for public health planning. When policymakers and health systems know that one in eight cancers can be linked to infections, it becomes easier to justify investments in vaccination programs, infection control, and education. While the summary does not delve into specific interventions, it strongly implies that addressing infections is a powerful lever in the effort to reduce cancer cases globally.
The timing and framing of this work also matter. Publishing the findings in a major oncology journal such as The Lancet Oncology places the issue squarely in the center of ongoing conversations about cancer prevention worldwide. By presenting cancer burden estimates that are anchored in the IARC Global Cancer Observatory and enhanced with new scientific insights, the authors provide a resource for researchers, clinicians, and public health professionals who are working to align cancer control strategies with the latest evidence.
There is also an important communication aspect to these results. Many people are aware that certain infections can cause cancer, but they may not realize how large a share of global cancer cases is involved. Quantifying the link as 2.3 million new cases in a single year gives the concept of infection related cancers a concrete scale. That number expresses not only a challenge but also an opportunity, because infections are often more directly preventable or treatable than many other cancer risk factors.
For individuals, these findings highlight the value of staying informed about vaccines and other tools that lower infection risk. The analysis itself does not provide a step by step guide, but it reinforces the idea that protecting against specific infections, when possible, is one part of a broader, long term approach to reducing cancer risk. On a population level, it stresses that global cancer control cannot be fully addressed without also paying attention to infectious diseases that are known to be carcinogenic.
As scientific knowledge evolves, estimates of the global burden of cancer attributable to infections will likely continue to be refined. New infectious agents may be identified as carcinogenic, and new associations between known pathogens and additional cancer types may emerge. This 2024 analysis provides an important benchmark for where the world stands now, with the understanding that the landscape of infection and cancer is dynamic.
The study by Rumgay and colleagues offers a sobering yet constructive picture. One in eight cancers linked to infections is a significant figure, but it also signals that a considerable proportion of cases may be avoidable through infection focused prevention and care. For anyone concerned with cancer control, from international agencies to local clinics, incorporating infections into the core of cancer strategies is not simply an added detail. It is a key part of the path forward for reducing the global burden of cancer.
