PRODUCT DESCRIPTION:
OVERVIEW:
What is the ER/PR receptors lab test?
An ER/PR receptors lab test is a diagnostic test for breast cancer. This test guides treatment of breast cancer and indicates prognosis and the effect of hormonal therapy on the disease.
Why is the ER/PR receptors lab test done?
An ER/PR receptors lab test is done in order to:
- Diagnose invasive breast cancer,
- Diagnose endometrial carcinoma and meningioma,
- Plan treatment of breast cancer,
- Get an idea about the prognosis of breast cancer,
- Know about the effect of hormonal therapies on breast cancer.
What does the ER/PR test measure?
An ER/PR test determines the presence of estrogen or progesterone receptors in the breast cancer cells. If only estrogen receptors are present then the tumor is named ER positive tumor and if only progesterone receptors are present then the tumor is named PR positive tumor. Both of these receptors can be present simultaneously in some types of tumors.
How do you test for ER/PR?
The most common method used to test a tumor for ER/PR is called immunohistochemistry or IHC.
Is it better to be ER/PR positive or negative?
It is better to be ER/PR positive because tumors that are ER/PR positive respond in a better way to hormone therapy and have a better prognosis.
What percentage of breast cancers are ER positive?
About 70-80% of breast cancers are hormone receptor positive.
What type of receptor is estrogen receptor?
Estrogen receptor belongs to the steroid hormone superfamily of nuclear receptors.
What does estrogen receptor negative status mean?
It means that the cancer cells do not have a protein that binds to estrogen hormone. Cancer cells that are estrogen receptor negative do not need estrogen to grow.
INTERPRETATION OF THE RESULT:
After testing, the doctor will be able to tell which of the following categories best describes breast cancer. Most breast cancers are hormone-receptor-positive.
ER+: About 80% of breast cancers are estrogen-receptor positive.
ER+/PR+: About 65% of estrogen-receptor-positive breast cancers are also progesterone-receptor-positive. This means that the cells have receptors for both hormones, which could be supporting the growth of breast cancer.
ER+/PR-: About 13% of breast cancers are estrogen-receptor-positive and progesterone-receptor-negative. This means that estrogen, but not progesterone, maybe supporting the growth and spread of the cancer cells.
ER-/PR+: About 2% of breast cancers are estrogen-receptor-negative and progesterone-receptor-positive. This means that the hormone progesterone is likely to support the growth of this cancer. Only a small number of breast cancers test negative for estrogen receptors but positive for progesterone receptors. More research is needed to better understand progesterone-receptor-positive breast cancers.
ER-/PR-: If the breast cancer cells do not have receptors for either hormone, the cancer is considered estrogen-receptor-negative and progesterone-receptor-negative (or “hormone-receptor-negative”). About 25% of breast cancers fit into this category.
An ER/PR receptors lab test is done in order to:
- Diagnose invasive breast cancer,
- Diagnose endometrial carcinoma and meningioma,
- Plan treatment of breast cancer,
- Get an idea about the prognosis of breast cancer,
- Know about the effect of hormonal therapies on breast cancer.