WEDNESDAY, May 9 (HealthDay News) -- One in six cancers worldwide is caused by preventable or treatable infections, a new study finds.

Infections cause about 2 million cancer cases a year, and 80 percent of those cases occur in less developed areas of the world, according to the study, which was published online May 8 in The Lancet Oncology. Of the 7.5 million cancer deaths worldwide in 2008, about 1.5 million were due to potentially preventable or treatable infections.

"Infections with certain viruses, bacteria and parasites are one of the biggest and most preventable causes of cancer worldwide," lead authors Catherine de Martel and Martyn Plummer, from the International Agency for Research on Cancer in Lyon, France, said in a journal news release. "Application of existing public-health methods for infection prevention -- such as vaccination, safer injection practice or antimicrobial treatments -- could have a substantial effect on future burden of cancer worldwide."

The researchers examined data on 27 cancers in 184 countries and calculated that about 16 percent of all cancers in 2008 were infection-related. The rate of infection-related cancers was 23 percent in developing countries and 7 percent in developed countries.

Rates of infection-related cancers ranged from 3 percent in Australia and New Zealand to 33 percent in sub-Saharan Africa.

"Many infection-related cancers are preventable, particularly those associated with human papillomavirus (HPV), Helicobacter pylori, and hepatitis B and hepatitis C viruses," the researchers said.

In 2008, these four main infections together caused 1.9 million cancers, mostly of the stomach, liver and cervix. Cervical cancer accounted for about half of infection-related cancers in women, and liver and gastric cancers accounted for more than 80 percent of infection-related cancers in men.

The study findings "show the potential for preventive and therapeutic programs in less developed countries to significantly reduce the global burden of cancer and the vast disparities across regions and countries," Goodarz Danaei, of the Harvard School of Public Health in Boston, wrote in an accompanying editorial.

"Since effective and relatively low-cost vaccines for HPV and [hepatitis B] are available, increasing coverage should be a priority for health systems in high-burden countries," Danaei added.

More information

The U.S. National Cancer Institute offers an overview of cancer prevention.