Would you fly across country to see an associate?

I wouldn't!

Is it feasible for your oncologist to send your case to Dr. Slamon for a review of your treatment. If Dr. Slamon thinks you should have additional tests, scans, etc., before he proposes a treatment, he could inform your doctor of this. In effect, if you use one of Dr. Slamon's associates that's about the same thing, with Dr. Slamon yea-ing or nea-ing the proposed treatment plan based on the information presented by the associate.

And if that doesn't work, I'd see another specialist.