Does this sound like gastric cancer very worried?

my dad had lost alot of weight fairly quick had a loss of appetite the feeling of being full had a chest xray came back fine had a ultra sound of stomach fine had a catscan afull abdomen focused on kidneys and came back he ahs 2 small cysts on each kidney he was complaining of a lot of pain in his stomach and nausiousness dr put him on th eprevpac triple pac for 14 days stomach feels much better but he is very very tired and appetite is minimal he says its not there and they found he had a very fast herat beat he had a cbc with diff and came back fine he had a rectal all fine he had a prostate check fine they checked his thyroid through blood fine they did some blood test called metabolic something they checked for prostate cancer all good but he still has no appetite and tired and now he is a little hoarse and has a little runny nose no cough his coumadin level was high so they took him off for awhile and just put him back on does this sound like gastric cancer i hope not

what a story.
He had quite some examinations, and most are ok. There are two reasons you mentioned that can cause fatigue, and that is a fast heartrate, and a too fast working thyroid.. But that doesn't explain the nausea. I nowhere read in your story that he had a gastroscopy..If he didn't I believe he should.
A gastric cancer is possible, but then his stool would be black (iron in bloodcells coming from cancer). Is that checked? Although it is unlikely because he takes coumadin, that would cause more serious bloodloss.
Most likely answer is a gastritis, but still not sure untill a gastroscopy is done.
So not ready yet...

Cancer is diagnose only by biopsey. If he has cancer the primary MD would consult an oncologist.
JM