My parents know a guy who has had prostate cancer for last 20 yrs. and he is around same age as my father. (83)

The problem is that they are clinging onto a belief that my father (who has prostate cancer and is spreading slowly now. Diagnosed 3 yrs. ago) will live like that guy...long.

This most likely will not happen, but we are dealing with denial.. It's a complicated situation. But other than this terminal disease, he has no other health problems.