I was wondering about that, too, Minh. My son's cancer was on the right under side of his tongue. In searching OCF in News, re HPV, I also noted this: "The study looked at patients with nasopharyngeal cancer, a tumor that grows behind the nose and at the top of the throat, above the tonsils. The quote was at this link:
http://oralcancernews.org/wp/rare-head-and-neck-cancer-linked-to-HPV-study-finds/
I'm sure someone else will be able to comment on this.