Then you'll likely get Herceptin along with either Taxotere and Carboplatin or another regimen , generally Adriomycin, Cytocin and Taxol. At the Herceptin web site Herceptin dot com you can read more about side effects and such. I also discovered there you can click the physician's link and look up efficacy stats with each regimen which were only released in the last couple of years. They treat the worst of your tumors so even if others were neg for Her2 protein, they'll treat for it if any of your tumors with it were 5mm or larger.
OK to answer this, I'm going to step up to one higher level. So bear with me.
There are 3 basic things the test all breast cancers for in order to put them in a subgroup: Estrogen, Progesterone and HER2. Hence, you will be diagnosed from your biopsy and final path report based on how "receptive" your cancer is to those 3 things.
ER = Estrogen receptive
PR = Progesterone Receptive
HER2 = HER2 receptive
In very basic terms, this is a test to see what causes your cancer to grow. If you are + to any of these things, it means that your cancer growth is fueled by that.
So we all know what Estrogen and Progesterone are (hormones). HER2 is just a protein that is naturally found in everyone's body. If you are HER2+, it means that the HER2 protein helps to fuel your cancer growth.
If you are HER2-, that means that your cancer is NOT receptive to HER2 protein.
To go one step further, all these tests do is give your doctors an understanding of your cancer so they know what treatments are the most effective.
Since you asked about HER2+, your treatment would differ from the other subgroups because you would also be given Herceptin. This is a mild form of chemo that is targeted directly at the HER2+ cancer.
Hope that helps!
I was diagnosed with three separate cancerous tumors .... and I have all three of those. They have to fight each cancer differently. (i've never missed a mammogram so I was pretty surprised that three came on so quickly).