I'm worried this is the last time I'll get to spend time with my granpa
Are you serious? Why could this be the last time?
I worry that the cancer will come back and he will die because of that. I hate cancer.
You should make the effort to go see him again then. It will make his whole day if you go to visit him.
That's impossible, he lives so far away.
You can try your hardest to go see him if you truly believe this is your last chance. Nothing should get in the way of taking out time to spend with your grandparents.