Wanting to know "our chances" is a very normal reaction. My research quickly brought me to the view that the data for things like 5 year survival rate are by definition historical. They don't reflect your chances "today", with the advances in imaging, diagnosis and treatment techniques we have available to us now. There are also less tangible variables that will impact your case against the statistical group you are comparing with.

I became pragmatic about the numbers. 80% cure rate I was given. That sounds high, but if that was your survival chances going to work you wouldn't go in on Friday!

There is not much point knowing that 15% of 747s crash after you're on board. What we really want to know is will THIS 747 crash! No one has the crystal ball to tell you that, its all a best guess on not just the historical stats but your staging, your age, smoking history etc. Its an educated guess, but a guess all the same.