I have the same, stage 3 non small cell lung cancer (nsclc).  Suspected in late January, confirmed during surgery at the end of March. It was locally advanced, in the lymph nodes in the centre of my chest, but no other locations. I'm in my late 60s.

My surgeon removed all the cancer he could find. I'll likely have chemo to try to knock out any cancerous cells floating about in the lymph system. There is still a possibility that I'll be cured. I may even have been cured by the surgery already, though it's unlikely.

Unfortunately there are no guarantees with this disease, but I am hoping for a good few more years even if it does advance.  Some cancer is suitable for immunotherapy if it does reappear (if it has a high PD-L1 expression), so there will still be options.

I was reading on this forum about a lady who had stage 4 lung cancer (spread to other organs) and she lived for many years with it.

Has your dad had any tests or treatment yet? If he's had surgery, it's not unusual to cough some blood, though it didn't happen to me. 

I'm a never-smoker. If your dad smokes it would make sense to stop.

I’m 62 andI have stage 3 nsclc and have just finished chemoradiotherapy 3 cycles and 30 radiation sessions, starting immunotherapy next month had ct scan just to make sure everything ok and it’s not spread, good news not spread and so far tumour has shrunk by half, fingers crossed all goes well .

Evidoll, thanks for your response.  That all sounds really positive.
Was surgery not an option for you, or is it something they may do later?  Or will the other therapies do the job?

They haven't mentioned radiotherapy for me, but I won't know the details until I see the oncologist on 10 June for the results of my CT scan.  Aaargh, another period of waiting in uncertainty!

I appreciate you sharing your experience and wish you all the best.