The increase in these cancers is a result of HPV infection. Almost all of these cancers are caused by HPV16, a subtype of the HPV virus. Research indicates that approximately 70 percent of cases of oropharynx cancer is caused by HPV16.
They can be spread by vaginal, anal, and oral sex (1).. Low-risk HPVs, which do not cause cancer but can cause skin warts (technically. Two of these, HPV types 16 and 18, are responsible for most HPV–caused cancers (2, 3).. . called cervical intraepithelial neoplasia 3, or CIN3), these do not always lead to cancer.