Prognostic value of estrogen receptor α and progesterone receptor conversion in distant breast cancer metastases.

Abstract

Changes in the receptor profile of primary breast cancers to their metastases (receptor conversion) have been described for the estrogen receptor α (ERα) and progesterone receptor (PR). The purpose of this study was to evaluate the impact of receptor conversion for ERα and PR on survival in a large group of distant non-bone breast cancer metastases. Receptor conversion was studied by immunohistochemistry in a group of 233 metastatic breast cancer patients. Kaplan-Meier overall survival curves were plotted, and differences between the curves were analyzed by log-rank analysis. The additional prognostic value of conversion to established prognosticators was studied by Cox regression. Overall survival of patients showing conversion from positive to negative ERα or PR, or from negative to positive ERα or PR, or remaining receptor negative was comparable, and significantly worse than patients remaining receptor positive. ERα or PR receptor conversion from positive in the primary breast tumor to negative in distant metastases has independent negative prognostic value. ERα or PR receptor conversion from positive in the primary breast cancer to negative in distant metastases has negative prognostic value.