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Estrogen and Progesterone Receptor Tests

Estrogen and progesterone receptor (ER/PR) tests identify whether these hormones affect the way that breast cancer grows. The results of these tests help doctors decide whether to use hormone therapy to help stop the cancer from growing or to lower the risk of the cancer coming back (recurrence).

The hormones estrogen and progesterone attach to certain receptors on the breast cells to stimulate the growth of normal breast cells and some breast cancers.

Breast cancer cells that lack these receptors (ER-negative and PR-negative cancers) are much less likely to respond to treatment with such medicines as tamoxifen or aromatase inhibitors. ER/PR-positive tumors have these receptors and are more likely to respond to treatment with tamoxifen or aromatase inhibitors.

By Healthwise Staff
Primary Medical Reviewer Sarah Marshall, MD - Family Medicine
Specialist Medical Reviewer Douglas A. Stewart, MD - Medical Oncology
Current as of June 28, 2013

WebMD Medical Reference from Healthwise

Last Updated: June 28, 2013
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.