Would you treat a premenopausal woman with T2N0 ER-, PR+ (15-20%), HER2- breast cancer with neoadjuvant chemotherapy like a triple negative breast cancer?

Yes, I would treat this patient with neoadjuvant chemotherapy as I would for a "triple-negative" breast cancer as certainly the biopsy of an ER 0%, weakly PR positive tumor is similar. I would not send an OncoType on this tumor - if it was low or intermediate, I still would not trust this patient wo...

Yes, I would treat her as a triple-negative patient and would not expect any benefit from adjuvant endocrine therapy. I also wouldn't waste the time or money to send a genomic assay, such as Oncotype, Mammoprint, or EndoPredict, as any of these are sure to confirm that this is a high-risk cancer tha...

Multiple pathology papers report that this is more likely than not a technical artifact and repeat staining should be done. Most of the time it will not be ER-PR+ on repeat stain (for example see Foley et al., PMID 28891017). This was specifically addressed in the recent ASCO/CAP guidelines for ER a...

First, I would repeat the PR. Also, calculate an Allred score. There are only 1% of cases where PR is + with a negative ER. Shouldn't happen. This is most times an anomaly and will be negative upon repeat. Then treat as triple-negative. There is no role for any other testing such as Oncotype or Endo...

I would get an OncoType Dx assay or a Mammoprint/Blueprint on the biopsy and treat it as per the results of that. She is not triple-negative breast cancer, but may well benefit from chemotherapy. There is increasing experience with using OncoType DX on neoadjuvant biopsies (Yardley et al., PMID 2650...

We are starting to use EndoPredict in order to determine which patients can be "de-escalated" and avoid neoadjuvant chemotherapy, and which HR+/HER2- patients would benefit from it.

Almstedt et al., PMID 32436145