Breast cancer markers
HER2 IHC 0 or 1+ (HER2 negative or HER2 low)
Also written as HER2 0, HER2 1+, HER2 low, HER2 negative, HER2-low, HER2 ultralow
What it means
An IHC score of 0 with no staining is called HER2 negative. A score of 1+ (or 2+ with a negative FISH) is called HER2 low. HER2 negative cancers do not respond to drugs that target HER2.
Why it matters
Some HER2 low cancers might respond to a type of drug called an antibody-drug conjugate. Your oncologist decides whether that applies to you.
Ask your oncologist
"My HER2 is 0 or 1+. Does HER2 low status matter for my treatment?"
From American Cancer Society: Breast Cancer HER2 Status. Not medical advice: your oncologist decides.