There needs to be some kind of cancer ombudsman who does this stuff, not people who are already shaking piles of goo.
The VA, man. They are awesome with this shit. Everything gets scheduled for you and you are notified where and when to show up, and they have you booked for whatever specialists/physiscians needed. One of the many factors that plays a part in their treatment and efficiency records.
They are dealing with a poplulation of largely retirees without enormous demands on their time, so I'm not sure how translatable to the general population. But I'd give it a go.