In the “old” way of doing thing, when primary and met sites were treated as only two “clumps”, the discordant rates between the two were about 17% for er/pr and 8% for her2. With newer technology, the break down has more detail as in the first link below. The tech in the second link is highly useful, since we can’t biopsy often. Incidentally, PR receptor seems to be one of the first to “go away” with endocrine treatment. In one of the Eribulin thread I posted some weeks ago, the research suggested Eribulin changes luminal type and possibly reverse er treatment resistance. We are testing this idea until one of these is widely available ds8201 (approved but not avail), sysd985, tucatinib(approved but not avail), or Margetuximab.
Nguyen
Discordance Rate in Estrogen Receptor, Progesterone Receptor, HER2 Status, and Ki67
https://journals.lww.com/appliedimmu...ceptor,.2.aspx
Recent Advances in Imaging Steroid Hormone Receptors in Breast Cancer
http://jnm.snmjournals.org/content/61/2/172.long