An estimated 2.3 million new cancer cases globally in 2024 were attributable to infections, accounting for about 12 per cent of all new cancer cases, a study published in The Lancet Oncology has found.
The study, titled “Global Burden of Cancer Attributable to Infections in 2024: A Worldwide Incidence Analysis”, provides an updated assessment of cancers linked to infectious agents.
Led by researchers from the International Agency for Research on Cancer (IARC), the study used data from the Global Cancer Observatory’s GLOBOCAN 2024 database. It assessed cancers attributable to 12 infectious agents classified as Group 1 carcinogens by the IARC Monographs Programme.
The researchers estimated population-attributable fractions, absolute numbers and age-standardised incidence rates by sex, age and country. They found that Helicobacter pylori (H. pylori) accounted for the largest number of infection-attributable cancer cases, with about 760,000 cases globally. Human papillomavirus (HPV) followed with about 750,000 cases, while hepatitis B virus (HBV) was linked to 360,000 cases. Epstein-Barr virus (EBV) accounted for about 260,000 cases, and hepatitis C virus (HCV) was associated with approximately 160,000 cases.
These five infections accounted for the majority of cancers attributable to infectious agents in the study.
The researchers said the findings underscored the importance of infection control in cancer prevention, noting that several of the infections can be prevented or treated. They identified interventions including HPV and HBV vaccination, testing and treatment for HIV, H. pylori, HBV and HCV, as well as safe injection practices. Other measures include condom use and pre-exposure prophylaxis to prevent HIV transmission, alongside screening for precancerous lesions linked to HPV-driven cervical and anal cancers.
The study found that eastern Asia recorded the largest absolute burden, with about 990,000 infection-attributable cancer cases, representing 42 per cent of the global total. Sub-Saharan Africa, however, recorded an age-standardised incidence rate of 28.5 cases per 100,000 people, higher than the global average of 22.7 cases per 100,000. Central and eastern Europe recorded 24.3 cases per 100,000, while southeastern Asia recorded 23.1 cases per 100,000.
The researchers said the analysis incorporated newly established infection-cancer associations and additional infectious agents, including HIV and Merkel cell polyomavirus. It also included additional cancer types associated with previously established carcinogenic infections, including the recently established link between EBV and gastric cancer.
A focused analysis of EBV-attributable cancers also showed substantial regional differences in the distribution of cancer types associated with the virus. The researchers said the findings could inform research and development investments in new cancer prevention tools, especially those targeting EBV.
They said strengthening vaccination, screening, diagnosis and treatment programmes could help reduce the global burden of cancers associated with infectious agents. The study noted that infectious agents remain an important preventable cause of cancer globally, making infection control a key component of broader cancer-control strategies.
