Background
Infection-attributable cancers account for a substantial share of the global cancer burden, with an estimated 13% of cancers worldwide linked to carcinogenic infections. Over recent decades, accumulating evidence has led the International Agency for Research on Cancer (IARC) to classify 11 infectious agents as group 1 carcinogens, highlighting the considerable potential for cancer prevention through infection control. Although effective preventive interventions such as vaccination and antiviral therapy are available, progress has been uneven across regions, with persistent disparities, particularly in low-income and middle-income countries. Updated and comprehensive estimates based on recent cancer data are therefore needed to better characterise the current burden and trends of infection-attributable cancers worldwide.
Objectives
To provide updated estimates of total and pathogen-specific infection-attributable cancers at the global, regional, and national levels in 2022, and to assess temporal trends from 1990 (1988–1992) to 2015 (2013–2017).
Methods
Ten infectious agents classified as group 1 carcinogens by the IARC were included: Helicobacter pylori, human papillomavirus (HPV), hepatitis B virus (HBV), hepatitis C virus, Epstein-Barr virus, human herpesvirus type 8 (HHV8), Schistosoma haematobium, human T-cell lymphotropic virus type 1, Opisthorchis viverrini, and Clonorchis sinensis (excluding HIV; Opisthorchis viverrini and Clonorchis sinensis were combined in the analyses). Cancer incidence data for 2022 were obtained from GLOBOCAN 2022 for 185 countries, with temporal trends examined using data from Cancer Incidence in Five Continents volumes VII–XII (1988–1992 to 2013–2017). Age-standardised incidence rates (ASIRs) were calculated using the Segi–Doll world standard population, and infection-attributable incidence was derived by applying previously published population-attributable fractions. Associations between 2022 ASIRs and the Human Development Index (HDI) were assessed, and temporal trends were quantified using log-linear regression models to estimate annual percent change (APC).
Results
In 2022, an estimated 2.50 million cancer cases were attributable to carcinogenic infections globally, accounting for 12.53% of all new cancer cases, including 1.07 million cases in men (10.35% of all cancers, ASIR 22.37 per 100,000) and 1.44 million in women (14.85%, ASIR 29.40). Among males, Helicobacter pylori accounted for the largest number of infection-attributable cancers, with approximately 484 000 cases (ASIR 9.88 per 100 000). Among females, HPV was the leading pathogen, responsible for about 718 000 cases (ASIR 15.14 per 100 000). Some regional patterns differed from the global distribution. Among males, cancers attributable to HHV8 were most common in southern Africa, whereas HBV-attributable cancers predominated in parts of Africa, the Americas, Asia, and Oceania. Among women, the burden of infection-attributable cancers was inversely associated with the HDI. Increasing trends in total infection-attributable cancer incidence were observed in several countries, including Turkey, Cyprus, and Belgium among men, and Cyprus, Turkey, Ireland, Latvia, and Belgium among women.
Conclusions
Carcinogenic infections remain a major contributor to the global cancer burden, with pronounced disparities by region, sex, and level of development. The persistent and, in some countries, increasing burden highlights substantial missed opportunities for prevention. Strengthening and expanding infection-targeted interventions should be prioritised as a core component of global cancer control, particularly in low-income and middle-income settings.

Country-specific ASIR per 100?000 person-years of total and pathogen-specific infection-attributable cancers by sex