Welcome to OCF.

I am not certain if people here would be able to help as when we talk about Oral Cancer, it is Squamous cell carcinoma.

I am not a medical professional but from my past reading, I believe that your friend here is probably dealing with Small Cell Neuroendrocrine Carcinoma with Parotid presentation. It is rare but curable and just like SCC, this too will have to go with Surgical removal followed by Concurrent Chemo-radiotherapy.

I see that surgery has already been performed, so progress with the rest of the course of treatment. Yes, it has to be concurrent chemo-radiotherapy.

Even though metastatic evaluation (was Whole Body PET performed?) was negative, if your friend did not had a second opinion, I would suggest one to rule out Merkel Cell Carcinoma.

Good to see caring friends! All the best to both of you.