
(Reuters) - Cancer of the back of the mouth and throat is on the rise, primarily because of more cases stemming from a viral infection called human papillomavirus (HPV), according to a U.S. study.The number of people who were diagnosed with HPV-related oral cancer in 2004 was triple the number diagnosed in 1988 -- due largely, researchers suspect, to changes in sexual behavior that have helped spread the virus.HPV is a very common sexually transmitted infection that can cause genital warts and certain cancers, including of the cervix, anus and penis."The whole relationship between HPV-related head and neck cancer completely changes our ideas of who is at risk, how to treat the cancer, the prognostics of the cancer, and prevention," said Maura...