Staging from surgery
 

I just finished my 3rd TCHP therapy. 3 down, 3 to go. Currently because of dense breasts the MRI didn't really show anything, the Onc doesn't think a ultrasound is needed. The breast surgeon said it is 2 cm but thinks nodes are fine.
My question is, when they do my surgery, if the TCPH therapy kills all the cancer cells in the SN's, is there a way they would know that the SNs did have cancer present at one time?
I have not had a PET Scan, but because I had a biopsy in 2011 that showed negative (but I probably had it then per current Dr.) I am afraid that being Her2+++ AND grade 3 that it is a strong possibility that it is elsewhere already. I am trying not to think negatively, but more realistically with the aggressiveness of what I have been diagnosed with. If my nodes all show negative, insurance will not do a PET scan, but if there is prove they were, then they will do one.
Is there a blood test that would show that it has metastasized? Any help with they questions would be appreciated!

Re: Staging from surgery
 

The more info you have the more confidence you have with your decisions. At least that it true for me. I don't know if there is any way to tell if your sentinel nodes ever had any cancer or not, a sentinel node biopsy will tell if there is any cancer there now.