Welcome Stacie. There are many suspected causes for squamous cell carcinoma in the head and neck, the majority being smoking, alcohol related, and viruses like HPV, Epstein Bar virus, and many others that are lesser known about. . I don't know if the negative HPV testing means it is not involved. It may depend on where the sample was taken from, type of HPV testing done, but I'm not totally sure. Anyway, outside clinical trials, they are both treated the same, but HPV pos for now seems to have better response, and prognosis over the other.

The treatment used afterwards is considered adjunct chemo therapy, and curious what type is being used. Is it the same type chemo used during your husband's treatment or a different chemo or targeted therapy?

Good luck with everything.