Infectious pathogens represent a very widespread, modifiable risk factor in oncology. To date, however, there have been no reliable surveys on the actual worldwide prevalence of infection-related cancers, although such surveys are important for prevention planning.
Researchers from France used the GLOBOCAN 2018 database for a worldwide inventory of infection-related tumor diseases. The data were based on the anatomical tumor localisations and histological subtypes recorded in the database, which are associated with ten common human pathogens and carcinogens. Using these data, the scientists calculated the absolute case numbers as well as the age-standardized incidence rates for infection-related cancer cases worldwide.
For the year 2018, there were a total of about 2.2 million infection-related cancers worldwide. The most frequently diagnosed pathogens were Helicobacter pylori (810,000 cases), human papillomaviruses (HPV; 690,000 cases), as well as hepatitis B (360,000 cases) and hepatitis C viruses (160,000 cases).
Age-standardized incidence rates were highest in East Asia (37.9 cases per 100,000 person-years) and sub-Saharan Africa (33.1 cases per 100,000 person-years). By contrast, the lowest incidences of pathogen-associated tumors were found in Northern Europe and Western Asia (13.6 and 13.8 cases per 100,000 person-years).
China led the ranking in both H. pylori and hepatitis B cancer cases, accounting for about one-third of all cases worldwide. HPV-induced cancer cases also showed a significant correlation with the income level of the countries concerned: the higher the per capita income, the lower the age-standardized incidence rate for HPV-induced carcinomas.
The current study from France shows one clear issue: pathogen-induced cancer cases are a serious health factor with more than 2 million people affected. Similar to obesity, lack of exercise, unhealthy eating habits, or smoking, however, infections are often preventable.
There are now reliable vaccinations against both hepatitis B and a large number of human papillomaviruses; type C viral hepatitis is in most cases curable thanks to new antiviral therapy methods.
Future prevention programs, therefore, aim to prevent viral infections through available vaccinations. In addition, it is also important to provide sufficient microbiological clarification for suspected diagnoses in order to detect infections early and, if necessary, to be able to treat them in a targeted manner before cancer develops.
The study authors conclude that high-risk populations, in particular, could benefit from this in the future, as not only the cancer burden but also the tumor-associated mortality could be favorably influenced by targeted prevention.
Source:
De Martel C et al., Global burden of cancer attributable to infections in 2018: a worldwide incidence analysis. Lancet Glob Health 2020