I assume like most GP's unless they have a particular interest in PCa most nurses don't have a wide knowledge of the disease. You might find it helpful to obtain the 'Toolkit' from the publications section of this charity. Also, it could be useful for you to speak with the specialist nurses on this charity but as Lyn suggested first obtaining a full report of Dad's diagnosis would give a better idea of his situation to them and us. As you are doubtless aware, Dad's prospects may depend on a number of factors, principally the type of cancer he has, how advanced it is and his treatment options. Advances in treatment and more treatment barriers to slow cancer advance for those that need it, mean that men have a better chance of living longer than they would have done a few years ago.
Generally, though not always, PCa is a slow developing disease which an increasing majority of men have as they get past 50 years of age, although a minority have it before 50.
It is important that Dad understands his treatment options and potential side effects and to help him remember what his consultant says, somebody accompanying him and even taking a few notes is recommended if possible.
I wish him well on his cancer journey