title: Global burden of cancers attributable to infections in 2008: a review and synthetic analysis.
abstract: BACKGROUND
  Infections with certain viruses, bacteria, and parasites have been identified as strong risk factors for specific cancers. An update of their respective contribution to the global burden of cancer is warranted.
  
  
  METHODS
  We considered infectious agents classified as carcinogenic to humans by the International Agency for Research on Cancer. We calculated their population attributable fraction worldwide and in eight geographical regions, using statistics on estimated cancer incidence in 2008. When associations were very strong, calculations were based on the prevalence of infection in cancer cases rather than in the general population. Estimates of infection prevalence and relative risk were extracted from published data.
  
  
  RESULTS
  Of the 12·7 million new cancer cases that occurred in 2008, the population attributable fraction (PAF) for infectious agents was 16·1%, meaning that around 2 million new cancer cases were attributable to infections. This fraction was higher in less developed countries (22·9%) than in more developed countries (7·4%), and varied from 3·3% in Australia and New Zealand to 32·7% in sub-Saharan Africa. Helicobacter pylori, hepatitis B and C viruses, and human papillomaviruses were responsible for 1·9 million cases, mainly gastric, liver, and cervix uteri cancers. In women, cervix uteri cancer accounted for about half of the infection-related burden of cancer; in men, liver and gastric cancers accounted for more than 80%. Around 30% of infection-attributable cases occur in people younger than 50 years.
  
  
  CONCLUSIONS
  Around 2 million cancer cases each year are caused by infectious agents. Application of existing public health methods for infection prevention, such as vaccination, safer injection practice, or antimicrobial treatments, could have a substantial effect on the future burden of cancer worldwide.
  
  
  BACKGROUND
  Fondation Innovations en Infectiologie (FINOVI) and the Bill & Melinda Gates Foundation (BMGF).
authors.affiliation: International Agency for Research on Cancer, Lyon, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: de Martel
authors.forename: Jacques
authors.initials: J
authors.lastname: Ferlay
authors.forename: Silvia
authors.initials: S
authors.lastname: Franceschi
authors.forename: Jérôme
authors.initials: J
authors.lastname: Vignat
authors.forename: Freddie
authors.initials: F
authors.lastname: Bray
authors.forename: David
authors.initials: D
authors.lastname: Forman
authors.forename: Martyn
authors.initials: M
authors.lastname: Plummer
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D001424:Bacterial Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D019049:Developed Countries; D003906:Developing Countries; D005260:Female; D014943:Global Health; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology* / Q000382:microbiology* / Q000503:physiopathology; D015995:Prevalence; D018570:Risk Assessment; D017678:Sex Distribution; D016019:Survival Analysis; D014777:Virus Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy