Cancer of the very back of the oropharynx can often involve the larynx. As to staging, even a stage two cancer in that area is often a call to do radiation which is the standard of care in anything outside of very early disease that they feel could be 100% removed through a TORS type of surgery. Even then oncologists often still prescribe radiation after surgery. So what you are describing seems normal, if you can ever call any cancer normal.
And being cautious and getting more scans is always prudent. That is not the same as the doctor believing that you have a lung extension of the cancer, that’s them covering all bases.
There’s a section of the main OCF website that explains staging and an important section after about statistics which might give you some reason not to expect the worse. I hope you will read those two areas. But essentially staging to the patient does not mean a lot. It’s designed as a way for doctors to talk to each other when perhaps only one of them has actually seen the patient. A stage two cancer has certain characteristics, the size of the primary, any metastasis of it or not, all black and white physical descriptions of the disease. By telling the other doctor it’s a stage two or three, the other doctor now knows lots of details about it without having actually examined the patient or scans. Staging also informs the treatment protocols normally employed. And guidelines are well established for any given stage of cancer in a specific anatomical site.
For patients staging has less meaning. A stage four patient has lots of downsides including a statistically poorer chance of a good long-term outcome. But those statistics do not apply to every patient. I was a very late stage four patient with bilateral mets and more. I’m still here 22 years later. Statistics are just that, numbers that may not apply to you, no mater your stage at the time of diagnosis.
Try to keep your fears in control, don’t let them take you to too many what if’s. It’s a time for the treatment team to learn everything, be sure they understand where you are, and develop a plan best design to resolve your situation. Patients usually feel better when everything is known, all the cards are on the table, and there seems to be a well thought out plan in place. For sure apprehension and even fear is part of a normal response. But with knowledge and a plan, the fear part can be tempered with a goal that allows them to see a positive outcome, even if they are still apprehensive of the journey itself.
As you learn more please come back and check in regularly. People in this group have done this dance, and they can be instrumental in helping you understand and cope with each step till you are out the other side of it all. You won’t be alone. B
https://oralcancerfoundation.org/discovery-diagnosis/stages-of-cancer/https://oralcancerfoundation.org/discovery-diagnosis/statistics/ 
