Certain cases of mouth cancer appear to be caused by a virus that can be contracted during oral sex, media reported, quoting a new Swedish study. People who contract a high-risk variety of the human papilloma virus, HPV, during oral sex are more likely to fall ill with mouth cancer, according to a study conducted at the Malmo University Faculty of Odontology in southern Sweden. "You should avoid having oral sex," dentist and researcher Kerstin Rosenquist, who headed the study, told Swedish news agency TT. HPV is a wart virus that causes many cervical cancers, including endometrial cancer (in the...