I totally relate to your "forward planning" question and I am 74! I remember this being discussed last year, I had the same question as you and I believe the answer was, if you have been on a preventive AI before Stage 4 it was OK to receive at least one of the CDK inhibitors as first line treatment for Stage 4 on the PBS. But only one had been approved, not both, and there were problems for people with co-morbidities. Maybe someone else can recall the thread? Good for you for raising it. It's true that they change the rules all the time but better to know than not when treatment options can cost such unmanageable amounts. All the best to you.