Hi! Mine was 3cm, and both surgeons I saw recommended surgery. I did not ask about radiation at the time, but have since learned it's generally not preferred for tumors this size. Others on this site can perhaps speak to this better than I can.
I had complications during surgery, and my recovery is ongoing. However, my tumor was unusual in that it had tentacles, like an octopus, which made the procedure more difficult. We had hoped to preserve hearing but it didn't work out that way. Also, the facial nerve was damaged, but not completely severed. So there was complete facial paralysis on that side for a while, but with time and therapy, most of the nerve has regenerated. I ended up with a wonderful speech therapist who worked on my facial paralysis, and along the way I learned that not all therapists approach this the same way. Some even recommended no therapy -- they were confusing AN with Bell's Palsey. Fortunately I ended up with someone who helped me immensely.
I live in a small city in the southeastern US, and was thankful to find an experienced surgeon within a few hours' drive. Given the complexity of my tumor, the outcome could have been much worse. I am grateful to the surgical team for minimizing the damage while removing virtually all of the tumor. I was also grateful to be so close to home when it came time to leave the hospital, because I had severe balance issues and nausea. I was using a walker. If we had flown, I can't imagine getting on a plane like that. Lots of people do -- there were neuro patients on my floor from all over the world. I think my level of balance loss was unusual (and I recovered well).
Don't know what your options will be in the UK, but I would encourage you to find someone with extensive AN experience. These tumors are tricky, and each is unique. There can be surprises once they get in there, as in my case. But despite the complications, I am recovered from much of it, and am learning to live with the rest -- and I mean live abundantly. It's the strangest thing, but this experience has actually been a blessing in many ways.
This is just my perspective. I hope it is helpful. You will see others with similar size tumors and less complications, with shorter recovery times. Their experience is probably more typical than mine. Each case is unique, and you have youth on your side. There is every reason to expect a successful outcome. Keep asking questions, continue taking care of yourself through nutrition and exercise, and work through the process. Because it is a process. Give yourself time to take it all in.
Keep us posted, and best wishes to you!