The risk is "tiny," in the words of New Scientist magazine, but an international research study concludes that oral sex could cause mouth cancer.

About one in 10,000 people develops mouth cancer each year, and more likely causes are smoking and drinking, the magazine points out. Scientists at the International Agency for Research on Cancer (IARC) are not recommending any changes in behavior.

A particular strain of the human papillomavirus (HPV) -- a very common source of sexually transmitted infection -- has been linked to cancer of the cervix. The same HPV16 strain was found in most of the studied cases of oral cancer, according to the IARC researchers, based in Lyon, France.

The study, published in the Journal of the National Cancer Institute, involved more than 3,400 participants. People with oral cancers containing the HPV16 strain were three times as likely to have had oral sex as oral cancer patients without the strain, the magazine says. And there was no statistical difference between men and women in how likely the virus was to be present in their cancers, according to the magazine's summary.

At any one time, about one-third of 25-year-old women in the United States are infected with HPV, New Scientist says. It is thought that about 10 percent of infections involve cancer-causing strains, and 95 percent of women will rid themselves of the infection within a year, the magazine adds.