Everybody has to die of something sometime.
I am an Atheist,so I dont need to explain why a God fearing person should die a death due to cancer.
This shopkeeper......from what you have described, no conclusions about his prognosis or treatment can be arrived at.
How do people deal with cancer? Depends on so many things, how old they are, what type of cancer it is, is it confined to the organ, has it spread locally, as it spread afar?
Terminal cancer is quite different....this means that the cancer is destroying the body and is advancing despite anti-cancer treatment. The end is nigh at this stage.
So often it is a serene ending and one wonders, at this stage, whether the body produces a substance like endomorphins to ease the final weeks, days or hours of your life.