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The loss of estrogen and progesterone receptor gene expression in human breast cancer

R G Lapidus1, S J Nass, N E Davidson

  • 1The Johns Hopkins Oncology Center, Baltimore, Maryland 21231, USA.

Journal of Mammary Gland Biology and Neoplasia
|May 20, 2000
PubMed

Insights

Understanding estrogen receptor (ER) and progesterone receptor (PR) loss in breast cancer is crucial. This review explores mechanisms behind ER/PR deficiency, impacting treatment and outcomes.

Area of Science:

  • Oncology
  • Molecular Biology
  • Genetics

Background:

  • Hormone responsiveness dictates breast cancer progression and endocrine therapy response.
  • Estrogen receptor (ER) and progesterone receptor (PR) status are key determinants.
  • Loss of ER/PR expression is linked to aggressive tumors and poor outcomes.

Purpose of the Study:

  • To review mechanisms regulating ER and PR expression in breast cancer.
  • To investigate causes of ER and PR loss, including genetic alterations.
  • To identify pathways leading to hormone-independent breast cancers.

Main Methods:

  • Review of existing literature on ER/PR regulation and loss in breast cancer.
  • Discussion of genetic mechanisms such as deletions, polymorphisms, and methylation.
  • Analysis of the functional relationship between ER and PR expression.

Main Results:

  • Approximately one-third of breast cancers lack both ER and PR.
  • Half of ER-positive tumors lack PR, indicating a non-functional ER pathway.
  • PR induction by ER serves as a marker for functional ER signaling.

Conclusions:

  • Understanding ER/PR loss mechanisms is vital for breast cancer management.
  • Identifying pathways of ER/PR deficiency can lead to better predictive markers.
  • Novel therapeutic strategies may target hormone-independent breast cancers.

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