Hi, Lat -
Try googling: oropharyngeal cancer HPV alternate staging

The old-style staging is being revisited by some of the top researchers for HPV associated cancer. There is a recent paper by Dahlstrom you should be able to find that will probably make you feel better about your husband's prognosis though nobody can say 100% cured. Maybe you can dial down the fret level.

I'm sorry to hear about your mom - that is a tough diagnosis at 82. Even if you pretty sure she will refuse treatment, it wouldn't hurt to look into some of the immunotheray clinical trials.

Best wishes and don't be like me and get a massive RA flare from all the caregiving stress!
Maria