You can’t catch cancer, or so many think. Cancer is considered a non-communicable disease by the World Health Organization, but among cancer’s many causes are viruses that can travel from person to person, and, if infection persists, lead to tumor growth. For example, the human pappilomavirus (HPV) often triggers cervical, anal and other cancers, which has prompted public health agencies to push mass vaccine campaigns for boys and girls alike (see ‘The value of HPV vaccination’).
The importance of making such prevention available around the world was made startlingly clear today in a study published online in The Lancet Oncology, which estimates that of the 12.7 million new cases of cancer in 2008, fully 16% were caused by infections. The vast majority of those cancer cases were caused by one of four pathogens: HPV, Helicobacter pylori and the hepatitis B and C viruses. Although infections by all these pathogens can be prevented with vaccines or treated with simple antibiotics, they nonetheless caused close to 2 million cases of gastric, liver and cervical cancer.
Today’s findings point to “a very large potential for cancer prevention by preventing infectious causes of cancer,” Goodarz Danaei, an epidemiologist at the Harvard School of Public Health in Boston who wrote an accompanying commentary, told Nature Medicine.
To determine the role of infection in causing cancer worldwide, the paper’s authors analyzed incidence, prevalence and mortality data for 27 cancers in 184 countries. Senior author Catherine de Martel says the findings published today are particularly important for developing countries, where approximately 25% of cancers are caused by infection. The most severely hit, the authors found, was sub-Saharan Africa, where nearly 1 in 3 cases of cancer are caused by preventable or treatable infection.
“This study highlights the need for cancer control priorities to be set in light of the burden of infection-related cancers, particularly in the low- and middle-income countries,” says de Martell, an epidemiologist at the International Agency for Research on Cancer in Lyon, France.
Artist’s rendering of HPV courtesy of Michael Taylor via Shutterstock