from website: mybiopsy.org: CAP and ASCO ER/PgR Test Guideline - College of American Pathologists

What to Know: The CAP and ASCO Guideline on Estrogen and Progesterone Receptor Testing for Breast Cancer Introduction To help doctors give their patients the best possible care, the College of American Pathologists and the American Society of Clinical Oncology (ASCO) developed evidence-based recommendations to improve the accuracy of testing for estrogen and progesterone receptors for breast cancer. This guide for patients is based on CAP’s and ASCO’s recommendations. Key Points: * Estrogen and progesterone receptors are found on breast cancer cells that depend on estrogen and related hormones to grow. * All patients with invasive breast cancer or a breast cancer recurrence should have their tumors tested for estrogen and progesterone receptors. * This testing should be performed by an accredited laboratory that follows specific testing procedures and handles the samples in a consistent way.