What does ER-positive mean?
Understanding estrogen and progesterone receptor status
The short version
ER-positive means the cancer cells have receptors for estrogen, which can help the cancer grow. It often means hormone therapy may be part of the treatment plan.
What ER and PR status mean
When a pathologist examines a breast cancer sample, they test it for and — proteins called hormone receptors. If the cancer cells have these receptors, estrogen or progesterone in the body can attach to them and may help the cancer grow.
Why it matters
ER and PR status is one of the main things your care team uses to help decide whether hormone therapy may be recommended as part of your treatment plan.
How results are usually reported
Pathology reports often describe ER and PR status as positive or negative, sometimes with a percentage of cells that tested positive. A cancer can be ER-positive, PR-positive, both, or neither — this is often reported alongside status.
- ER-positive / PR-positive: hormone therapy is often discussed
- ER-negative / PR-negative: hormone therapy is typically not expected to help
- Results can differ between ER and PR — your care team can explain what your specific combination may mean
Questions you may want to ask
How does my ER/PR status affect my treatment options?
Will I need hormone therapy, and for how long?
Could my hormone receptor status change over time?