Is HPV a cause of head and neck cancer and does this mean it is an std?

Yes. Hpv is one of the factor in oropharyngeal cancers, alcohol and tobacco being more important. It is a sexually transmitted disease but oral infections is acquired usually through kissing, which is generally not considered sexual activity.
Yes & no. Certain head/neck cancers (oropharynx, tonsil, tongue) are associated with hpv infections in ~40% cases; typically in young non-smokers & non-drinkers and also young women. These cancers respond better to standard treatments. Oral sex is a risk for hpv infection in the oral areas but typically an std refers to infections such as gonorrhea, chlamydia, herpes, etc.
Possibly. Interesting question hpv is now becoming an increasing risk for head and neck cancer. Most people are exposed to it but only a small percentage develop oropharyngeal cancer. That is why it is recommended to give young boys the vaccine. It is in some way an std yes. Unclear if oral sex is the cause !
Yes to both. Hpv has been increasingly implicated in head and neck squamous cell cancer (usually tonsil, base of tongue) and is transmitted through sexual contact. It also may be trasmitted through other froms of contact making it not exclusively a std.

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