As I looked back on this issue, momentum roughly a year ago was away from the test. Now it's moving towards embracing it. From what I can tell, there is more support in monitoring direction as opposed to the importance of starting levels. Which is..kinda like tumor markers. Although..the one study using Lapatinib claimed no correlation to treatment.
I have compiled what I could find on Serum HER and EGFR testing and put it here:
http://her2support.org/vbulletin/sho...48#post2256488