[Lani]

I usually estimate that 55-60% of breast cancer is ER+her2-
10-13% or so is her2+ER-
9-12% or so is triple +
15-22% is triple negative

This is not exact as they usually estimate that about 66% of bc is ER+, 34% ER- But then, ER testing is not that exact either and her2 testing when not done in central laboratories can vary as well (although it is getting better)

So these are ballpark figures

They are based on IHC(immunohistochemistry using stains and monoclonal antibodies on slides of formalin preserved tissues), not molecular subtypes, which are based on gene arrays(best done on fresh frozen tissues)

By the way, a high Ki67 is not unique for triple positive-- it is characteristic for her2+er- and basal type triple negatives as well. It is just what may differentiate it from ER+ her2- (although those can also have a high Ki67 and be categorized as luminal B)

Hope this helps!

It is hard to correlate them with subtypes ie, Luminal A, Luminal B, her2 and basal subtypes as large proportion of triple negatives are not basal, a smallish percent of ER+her2-s are Luminal B--they have a high Ki67 but not because of amplification of her2 or its signalling pathway , and not all triple positives really fit into the Luminal B category.

There still is a lot to learn it seems

Six and seven years ago a lot of papers said triple positive bc was rare--that has been disproved. Was the second opinion doctor at a major cancer center or an oncologist who treated only/mainly breast cancer?

There is a lot of literature to keep up on regarding her2+ breast cancer-- it is a relatively quickly evolving field.