Punters out there who engage in reverse oral would need to be aware of the risks associated with the practice. Recent scientific evidence from the U.S. has established that Human Papilloma Virus (HPV) which causes cervical cancer in females and also causes genital warts is strongly linked to throat cancer. The HPV virus may be passed on during oral sex. It does not show up in S.T.I. screenings as there are no established tests for it. Although throat cancer is a relatively rare condition , the research suggests that the HPV virus is a more potent cause of this cancer than smoking. For more information , google "HPV virus and throat infections".