Update about my old man's cancer diagnoses:
We caught it early enough. PET scan showed it contained only to the stomach, which is rare for that type of cancer (usually symptoms appear after it has spread to lymph nodes and potentially the liver). 'Localized' stomach cancer has about a 70% survival rate for 5 years (with surgery), and the oncologist wants us to be a little more aggressive with the treatment (still pushing for chemo before and after surgery), so odds might be a bit better than that even.
Again, thanks to all those who commented and/or reached out. Your leader appreciates your devout loyalty.