Tumor both HER2+ and HER2-

[SunCrystal]

Is there anyone else whose tumor was diagnosed as heterogenous with HER2+ and HER- sections? My biopsy sample was HER2+ but following my mastectomy surgery, the tumor itself was found to be HER2-. Both pathology labs conducted FISH. I had the FISH tests repeated at a 3rd independent pathology lab and they obtained the same results with HER2+ for the biopsy sample and HER- for the mastectomy tumor. I know this is pretty rare--but I am wondering what others' experiences have been and what treatment was recommended. My oncologist just started me on herceptin and taxol a week ago after 4 dose-dense AC treatments.