Background: Seven viruses and one bacterium endemic to Australia have been identified by IARC as Group 1 carcinogens, but it is unknown how many cancers in Australia are caused by these infectious agents. Here we present estimates for the fractions of cancers in Australia in 2010 attributable to infections.
Methods: The population attributable fraction (PAF) and number of cancers caused by Hepatitis B and C viruses (HBV, HCV), Helicobacter pylori and human immunodeficiency virus (HIV), were calculated using standard formulae incorporating prevalence of infection in the Australian population, the relative risks associated with that infection and cancer incidence. For cancers with very strong associations to the infectious agent (Epstein-Barr virus (EBV), human papillomavirus (HPV) and HIV/Kaposi’s sarcoma herpes virus (KSHV)) calculations were based on viral prevalence in the tumour.
Results: An estimated 3,421cancers (2.9% of all cancers) in Australia in 2010 were attributable to infections. Infectious agents causing the largest numbers of cancers were HPV (n=1,706), H. pylori (n=793) and HBV/HCV (n=518). Cancer sites with the greatest number of cancers caused by infections were cervix (n=818), stomach (n=694) and liver (n=483). Cancers with the highest proportions attributable to infectious agents were Kaposi's sarcoma (100%), cervix (100%), nasopharynx (87%), anus (84%) and vagina (70%).
Conclusions: More than 3,400 cases of cancer occurring in the Australian population in 2010 could be attributed to infectious agents. Opportunities for cancer prevention through infection control are considerable, even in a “first world” nation like Australia.