If you had ever seen someone die of cancer you would not call it 'graceful'.
Maybe some people get lucky and some don't.
I had a close relative who died of cancer last year. She first contracted it 38 years ago and survived at a time when nearly everyone who had the type of cancer she did (a melanoma) died quickly. She had surgery and a fair amount of luck.
When exactly the same cancer came back a couple of years ago she had surgery again and when finally the statistics were much more on her side she got unlucky and died.