However, further analysis of this association controlling for continuous levels of ER in a Cox model in the ER + /PR − subgroup of patients still showed statistically significant worse DFS and OS in women with HER-1–positive tumors than in those with HER-1–negative tumors (data not shown), suggesting that the lower ER level in the HER-1–positive, ER + /PR − tumors does not fully. Introduction. Estrogen receptor (ER) and progesterone receptor (PR) testing are performed in the evaluation of breast cancer. While the clinical utility of ER as a predictive biomarker to identify patients likely to benefit from hormonal therapy is well-established, the added value of PR is less well-defined. Tumors that are ER/PR-positive are much more likely to respond to hormone therapy than tumors that are ER/PR-negative. You may have hormone therapy after surgery, chemotherapy, and radiation are. → Topic: Benefit of Tamoxifen for ER positive but PR negative Topic: Benefit of Tamoxifen for ER positive but PR negative Forum: Hormonal Therapy - Before, During, and After — Methods. Typically, 1,260 female breast cancer patients were recruited in this study. The correlation between estrogen receptor (ER)/progesterone receptor (PR) phenotypes and clinical characteristics was investigated, and the survival rate was assessed after 5-year follow-up. ER-positive breast cancer is the most common type of breast cancer diagnosed today. Find out what ER-positive breast cancer means and learn about treatment options as well as long-term prognosis. Breast cancer is a highly heterogeneous disease. Tamoxifen is a selective estrogen receptor (ER) modulator and is mainly indicated for the treatment of breast cancer in postmenopausal women and postsurgery neoadjuvant therapy in ER-positive breast cancers. Interestingly, 5–10% of the ER-negative Most ER-positive breast cancers are also PR positive. Breast tumors that contain estrogen and/or progesterone receptors are sometimes called hormone receptor positive (HR positive). Breast cancers that lack estrogen receptors are called estrogen receptor negative (ER negative). Breast tumors are tested to see if they are estrogen receptor (ER) and/or progesterone receptor (PR) positive or negative. Hormone receptor tests are both prognostic and predictive. And, cancers that are ER-negative tend to be PR-negative. Sometimes, a breast cancer is ER-positive, but PR-negative. Because current hormone therapies are designed to treat ER-positive cancers, these cases are treated the same as breast cancers that are positive for both hormone receptors.