Herceptin and Tamoxifen

I am 36 and had a lumpectomy for 1 cm and sentinel node with only sentinel node microscopically affected.  I had 4 treatments of A/C and am doing radiation.  I am borderline positive for estrogen and progesterone negative.  My HER2 was +1 for IHC, but they did the FISH too and it was positive.  Could it be retested or is it ok that the IHC was essentially negative and then the FISH was positive?  The Dr's are recommending tamoxifen even though I'm borderline estrogen positive.  I still had my periods thru chemo regularly and thought about having another child(although I know that I am priority now).  And Dr's are recommending Herceptin.  Should I be confident with those results and take Herceptin?  What is the usual treatment schedule for Herceptin?  And should I take the Tamoxifen as well with Herceptin?  I can't thank you enough for your help!

[CCF-RN,MSN-rf]

Dear NeiceLynn:  There are two main ways to test Her-2/neu status: immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH). IHC measures the amount of Her-2/neu protein present. FISH looks at the genetic level for actual gene amplification - the number of copies of the gene present. Both FISH and IHC have their advantages and disadvantages, and both require experienced technologists and pathologists to yield accurate and reproducible results. IHC is an excellent screening technique, with negative and high (3+) overexpression cases readily identified. Furthermore, the IHC technique requires less technician and pathologist time, offers faster turnaround time, and is less expensive. FISH is superior at providing reproducible quantitative information at low levels of gene amplification. However, FISH requires significantly more technician and pathologist time, and is considerably more expensive. Since the FISH is considered to provide the more reproducible result, it would appear that your Her-2 status is positive.  In women whose cancers are Her-2 positive, clinical trials have demonstrated a benefit to using Herceptin in addition to chemotherapy.  In those trials, when hormonal therapy (such as tamoxifen) was indicated, it was generally given along with the Herceptin but after completion of chemotherapy.  Chemotherapy is more likely to affect future fertility than is tamoxifen, however, by the time you have completed 5 years of tamoxifen you will be at an age where fertility is questionable even in women who have not been treated for cancer.  It is important that you not attempt to get pregnant while taking tamoxifen or Herceptin as there may be detrimental effects to the fetus.