From my past experiences, I have been informed that thyroid cancer does not spread to breast cancer. Do you know what type of thyroid cancer she had? And how was it treated?
Prayers for your sister that her breast biopsy comes back benign! Stay positive and keep strong!
C
Not really ... it would be best to wait for the biopsy results. Although they may seem to be the same type of cells they don't necessarily need to be related. Regards ....