Diagnostic and Prognostic Roles of Universal Estrogen Receptor Testing in Endometrial Carcinoma

Estrogen receptor (ER) immunohistochemical evaluation has emerged as a key variable in the risk assessment of endometrial carcinoma. In the most common molecular subtype of endometrial carcinomas, the no specific molecular profile, ER is used in conjunction with stage, grade, and lymphovascular space invasion (LVSI) for risk assessment and guiding adjuvant treatments. Additionally, ER is a useful tool for aiding primary site and histotype assessment and has a role in predicting response to hormonal therapies for endometrial carcinoma. These applications of ER immunostaining will be reviewed.