Infections linked to 1 in 8 cancer cases worldwide, study finds
According to a study, infections may be the cause of one in every eight cancer cases worldwide, and many of these infections can be controlled through vaccination.
Scientists at the International Agency for Research on Cancer report that out of the 19.2 million new cancer cases identified in 2024, approximately 2.3 million were linked to infections. The majority of these cancer cases were associated with just five types of infections.
These include Helicobacter pylori (H. pylori), a common bacterium that affects the stomach and often spreads through contaminated food and water. Other pathogens include the human papillomavirus (HPV), hepatitis B and C, and the Epstein-Barr virus—the latter being particularly known for causing glandular fever.
Low- and middle-income countries bore the heaviest burden of infection-related cancers, accounting for approximately 77 percent of such cases reported globally.
East Asia recorded the highest number of infection-linked cancer cases—approximately 900,000—representing 42 percent of the global total. H. pylori and hepatitis B were identified as the primary causes.
In the study, published in the medical journal The Lancet Oncology, researchers stated that these findings highlight the importance of preventing and effectively controlling infections to reduce cancer rates. While investment in the development of new protective vaccines is important, many cancer prevention strategies are already known and can prove effective at a low cost.
💡 Key Prevention Strategies
According to researchers, these strategies are often not adequately implemented. They highlighted measures such as increasing HPV vaccine uptake, promoting safe injection practices, improving access to contraceptives and HIV prevention medications, and ensuring timely diagnosis and treatment of early-stage cervical and anal cancers.
In 2024, approximately 24,000 cases of HPV-related cancer were reported in Western Europe, making it the leading cause of infection-related cancer in the region.
There are approximately 14 types of HPV considered high-risk. These types can increase the risk of cancer; over time, they induce changes in cellular DNA, causing cells to grow uncontrollably and potentially leading to cancer.
Almost all cases of cervical cancer are caused by HPV. Additionally, HPV is linked to cancers of the throat, mouth, anus, vulva, and vagina. For this reason, HPV vaccination and cervical screening are fundamental components of the World Health Organization’s strategy to eliminate cervical cancer. The HPV vaccine, typically administered to children aged 12 to 13, can significantly reduce the risk of associated cancers. This vaccine is also available to individuals who missed receiving it during their school years.
The study also revealed that H. pylori was the leading cause of infection-related cancers worldwide in 2024, accounting for approximately 760,000 cancer cases—the majority of which were stomach cancers. According to the research, individuals previously exposed to this bacterium may face a nearly 60% higher risk of colorectal cancer (cancer of the colon and rectum).
Researchers note that progress in developing a vaccine against H. pylori has been slow so far, even though experts believe such a vaccine could play a significant role in reducing stomach cancer rates globally.
Why it matters: With nearly 2.3 million cancer cases linked to preventable infections, this study underscores the urgent need for global vaccination efforts and accessible screening programs. Many of these cancers could be avoided through existing, low-cost interventions—making implementation and public health investment critical.
