For patients with metastatic HER2-null breast cancer, do you offer trastuzumab deruxtecan based on the DAISY trial results?

DAISY trial was a small trial and the outcome was hypothesis-generating rather than practice-changing. With that said, I offer trastuzumab deruxtecan to patients with metastatic breast cancer even if HER2 IHC on biopsy of metastatic disease was 0 but historically, their primary tumor tested at least...

This question begs another update for the ASCO/CAP guidelines on the description of HER2 positivity/negativity and/or HER2 low expressors. The first ASCO/CAP guidelines on HER2 interpretation in breast cancer were released in 2007 and subsequently updated in 2013 and 2018. The most recent updated 20...

Based on the results of DESTINY-Breast06, we now can divide HER2 IHC 0 tumors into HER2 ultralow (meaning, IHC 0 but with faint HER2 expression on 1-10% of tumor cells) or HER2 null (meaning, IHC 0 with 0% of tumor cells showing any HER2 expression). Based on the DESTINY-Breast06 results, I would of...

Breast cancer evolution and tumor progression are governed by the complex interactions between steroid receptor (ER/PR) and growth factor receptor (HER) signaling highlighting the intimate crosstalk between the hormone and HER family signaling pathways as a contributor of resistance to therapy which...