BRCA1 from TNBC to HER2 positive?

jennybg

Hello! I was diagnosed with TNBC in 2011 at the age of 33. An year later tested positive for BRCA1 founder / 5382ins/ mutation. Mom has ovarian cancer and the same mutation, gradma died at the age of 40 from breast cancer.
Two months ago this year I had a recurrence in the same left breast and a new cancer in the other breast. What surpised me this time is that the recurrent tumor in the left breast is Er-, Pr-, and HER /3+/ positive, instead of TNBC, like the previous one.Unfortunately the HER2 status can be conferred only by IHC .CISH or FISH are impossible to be done due to bad laboratory fixing of the tumor sample. On the other hand, the tumor on the right breast is triple negative. I find this very perplexing.
My oncologist said that BRCA1 breast cancers are mostly triple negative, while HER2 possitive BRCA1 cancers are very rare
/only 2-3 %, if any/.nRight now I should start chemo, but I am not sure about adding Herceptin to it.
Have any of you ever been diagnosed wirh a BRCA1 hormone receptor negative BRCA1 + BC that is HER2 positive?