Why Hormone Receptors Matter in Breast Cancer
The hormones in your body that launched you into puberty and controlled your monthly period can play a role in breast cancer.
Most breast cancers -- about 70% -- are sensitive to the hormones estrogen or progesterone. These tumors have a sort of biological on-off switch called a hormone receptor. Estrogen and progesterone can flip these switches "on" and quicken the cancer cells' growth.
Your doctor will check to see if your tumor has hormone receptors. If it does, she may call it "hormone-receptor positive," “ER-positive,” or “PR-positive.”
For advanced cases, your doctor may want to repeat these tests after a while to see if the disease has changed. It may respond differently to hormones than before. The results will help your doctor find the best treatment at any stage.
How It's Different
Compared with other types of breast cancer, hormone-receptor-positive ones, also called HR-positive, tend to:
- Grow more slowly
- Respond better to hormone therapy
- Have a better outlook (prognosis)
Testing for Hormone Receptors
In advanced cancer, your doctor will take a small part of the cancer that has spread to your lymph nodes, liver, or other areas of your body. She may use a very fine needle or get the tissue during surgery. Lab tests will show if the disease has hormone receptors.
If you're taking hormones, you may need to stop before getting the test.
Cancer cells may have:
- Estrogen receptors only. Your doctor will call these “ER-positive” or “ER+” cancers.
- Progesterone receptors only. These are “PR-positive,” or “PR+.”
- Both estrogen and progesterone receptors, which doctors call “hormone-responsive”
- Neither estrogen or progesterone receptors, called “hormone negative” or “HR-"