towards a rational tailored approach to who should receive herceptin/lapatinib/both

Lani,
You are so incredibly informative and knowlegeble. I hope that you might be able to give me some help on the following:
I am breast cancer stage IV, and have been Her2+++ positive since the beginning [10 years]. About three months ago I developed cancer on my lymphedema arm, I had three biopsys of the arm and it showed me not longer Her2 positive [fully cancerous], my oncologist failed to inform me of the new finding until last week when I asked him if the Her2 results were back. He has kept me on Herceptin nevertheless and wants me to continue with it, and when I asked him why, he stated that there is no way to know if the rest of the body is still Her 2 positive or not. I am virulently progressing under my current medications. In your research do you happen to have come across some information my doctor doesnt have. You are truly a gift to this Her2 Site. I hope I am not asking too much from you. Thank You, Patricia