Hi Chris 

I'm answering you as i believe you're in an absolute mad panic.

Nearly all oncologist appointments have a nurse there, she's specifically a cancer nurse there to answer questions from the consultation about your fathers cancer diagnosis and deal with any requirements from the appointment so whoever told you to expect the worse by a nurse being in attendance is in my personal opinion deluded to be honest. I would tell you to expect one as a matter of routine proceedure and nothing more.

There is nothing you can watch out for prior to entering the appointment that might mean no treatment either, it's the standard hospital department waiting room with usual reception.

Go to the appointment with this in mind: The fact he's having an oncology appointment suggests they intend to discuss something and my feeling as a cancer patient who attends on oncology appointment is hopefully treatment of some sort. 

You are clearly aware this is advanced by the stage and spread and i feel also aware there is a POSSIBILITY of no treatment options.

IF that is said ask if there are any clinical trials he maybe suitable for however you should discuss this with him first as it comes down to what he wants.

The meeting of that nurse will give you her contact details precisely for questions like this, that you will think about when you get home or over the next days to come.

Don't spend the appointment looking for signs of things. Listen intently and make notes on what is actually being said with regards what might be on offer.

Really hoping this will help, best of luck with it. Keep calm as you need a clear head.