Do the Cancer Cells Have Hormone Receptors?

Hormone receptors are like ears on breast cells that listen to signals from hormones. These signals "turn on" growth in breast cells that have receptors.

A cancer is called "ER-positive" if it has receptors for the hormone estrogen. It is called "PR-positive" if it has receptors for the hormone progesterone. Breast cells that do not have receptors are "negative" for these hormones.

Breast cancers that are either ER-positive or PR-positive, or both, tend to respond well to hormone therapy.

These cancers can be treated with medicine that reduces the estrogen in your body. They can also be treated with medicine that keeps estrogen away from the receptors.

If the cancer has no hormone receptors, there are still very effective treatments available.

You will see the results of your hormone receptor test written in one of these three ways:

• The number of cells that have receptors out of 100 cells tested. You will see a number between 0% (no receptors) and 100% (all have receptors).
• A number between 0 and 3. You will see the number:
  • 0 (no receptors)
  • 1+ (a small number)
  • 2+ (a medium number)
  • 3+ (a large number of receptors)
• The word "positive" or "negative."