Endocrine therapy resistance: what we know and future directions

Area of Science:

• Oncology
• Molecular Biology
• Endocrinology

Background:

• Endocrine resistance is a significant challenge in treating estrogen receptor (ER)-positive breast cancer.
• Aberrant molecular signaling pathways and ER dysfunction contribute to treatment evasion.
• Targeting these specific evasion mechanisms is crucial for improving patient outcomes.

Purpose of the Study:

• To review molecular signals driving endocrine resistance in ER-positive breast cancer.
• To explore the crosstalk between key signaling pathways involved in resistance.
• To highlight recent clinical trials investigating targeted therapies for endocrine-resistant breast cancer.

Main Methods:

• Literature review of molecular signaling pathways.
• Analysis of crosstalk mechanisms between MAPK, PI3K/AKT, mTOR, CDK4/6, and ER.
• Summary of recent clinical trial data on targeted therapies.

Main Results:

• Identified key molecular signals including mitogen-activated protein kinase (MAPK), phosphoinositol-3 kinase/protein kinase B (PI3K/AKT), mechanistic target of rapamycin (mTOR), and cyclin-dependent kinases 4 and 6 (CDK4/6).
• Detailed the crosstalk among these pathways and aberrant ER function contributing to resistance.
• Summarized promising results from clinical trials targeting these pathways.

Conclusions:

• Understanding the molecular basis of endocrine resistance is vital for developing effective treatments.
• Targeted therapies addressing specific signaling pathways show promise for overcoming endocrine resistance.
• Further clinical investigation is warranted to optimize treatment strategies for endocrine-resistant breast cancer.