Estrogen Receptor Positive/Progesterone Receptor Negative Breast Carcinomas: A Subgroup Deserves Particular Interest

Abstract

Objective: Breast carcinomas positive for the estrogen receptor (ER+) but negative for the progesterone receptor (PR-) have unfavorable prognostic features and are resistant to tamoxifen therapy. The goal of this study was to highlight the significance of PR-breast carcinomas.