Global burden of cancer attributable to infections

Martyn PLUMMER, International Agency for Research on Cancer, France

1 Infection and Cancer Epidemiology Group, International Agency for Research on Cancer, Lyon, Franc
2 Cancer Surveillance Section, International Agency for Research on Cancer, Lyon, France

Purpose. Infections with certain viruses, bacteria, and parasites have been identified as strong risk factors for specific cancers. The aim of this study is to quantify the impact of these infections on the global burden of cancer.

Methods. We considered infectious agents classified as carcinogenic to humans by IARC. We calculated the number of cancers attributable to infections by country by combining statistics on estimated cancer incidence in 2012 with estimates of population attributable fraction for the infectious agents. Incidence estimates were obtained from GLOBOCAN 2012. Attributable fraction calculations were based on the prevalence of infection in cancer cases combined with the relative risk for the infection. Estimates of infection prevalence and relative risk were obtained from reviews of published data.

Findings. Of the 14 million new cancer cases that occurred in 2012, 2.2 million were attributable to carcinogenic infections.  The most important infectious agents were Helicobacter pylori (770 000 cases worldwide), human papillomavirus (640 000 cases), hepatitis B virus (420 000 cases) hepatitis C virus (170 000 cases) and Epstein-Barr virus (120 000 cases). Globally, 15.4% of all cancers were attributable to infections. The fraction of cancers attributable to infection varied by country from under 5% in the United States, Canada, Australia, New Zealand and some countries in Western and Northern Europe to over 40% in some countries in sub-Saharan Africa. The spectrum of infectious agents causing cancer also varied by development status as measured by the UN human development index.

Interpretation. Over 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.

Funding. Fondation de France.