Hormone Receptor Status

Also known as: Estrogen receptors; Progesterone receptors; ER and PR status

Formal name: Estrogen and Progesterone receptor status

The Test Sample

What is being tested?

Estrogen receptors (ER) and progesterone receptors (PR) are specialized proteins found within certain cells throughout the body. These receptors bind to estrogen and progesterone, female hormones that circulate in the blood, and promote new cell growth and division.

Many breast cancer tumors have receptors for estrogen and/or progesterone, often in large numbers. These tumors are said to be hormone-dependent, and estrogen and/or progesterone feed their growth. Breast cancer tissue can be tested to see if it is positive for these receptors.

How is the sample collected for testing?

A sample of breast cancer tissue is obtained by doing a fine needle aspiration, needle , or surgical biopsy or when a tumor removed surgically during a lumpectomy or mastectomy is tested.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

Your doctor may have you discontinue taking hormones for a time period before your sample is collected.