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[Antihormonal therapy in breast cancer and mTOR inhibitors]

Pierre-Étienne Heudel1, Olivier Tredan, Isabelle Ray-Coquard

  • 1Centre Léon-Bérard, oncologie médicale, Lyon, France. pierre-etienne.heudel@lyon.unicancer.fr

Bulletin Du Cancer
|December 3, 2011
PubMed

Insights

Many estrogen receptor-positive breast cancers resist hormonal therapy due to pathway dysfunctions. Combination therapies targeting both estrogen and PI3K/Akt/mTOR pathways may overcome this resistance.

Area of Science:

  • Oncology
  • Molecular Biology
  • Endocrinology

Background:

  • Hormonal dependence is a known characteristic of many breast cancers.
  • Approximately 50% of estrogen receptor-positive breast cancers exhibit resistance to anti-hormonal therapies.
  • Mechanisms of resistance involve dysregulation of the estrogen pathway or growth factor pathways, notably PI3K/Akt/mTOR.

Purpose of the Study:

  • To investigate the mechanisms underlying resistance to anti-hormonal therapy in estrogen receptor-positive breast cancer.
  • To explore the potential of combination therapies to overcome treatment resistance.

Main Methods:

  • Review of existing literature on breast cancer hormonal dependence and resistance mechanisms.
  • Analysis of the roles of the estrogen receptor pathway and the PI3K/Akt/mTOR pathway in treatment resistance.
  • Identification of potential therapeutic agents targeting these pathways.

Main Results:

  • Resistance to anti-hormonal therapy is linked to dysfunctional estrogen and/or PI3K/Akt/mTOR signaling pathways.
  • Specific inhibitors like SERMs and aromatase inhibitors target the estrogen pathway.
  • Temsirolimus and everolimus are identified as inhibitors of the PI3K/Akt/mTOR pathway.

Conclusions:

  • Dysfunction in estrogen or PI3K/Akt/mTOR pathways contributes to anti-hormonal therapy resistance in breast cancer.
  • Combination therapy involving anti-estrogens and PI3K/Akt/mTOR inhibitors presents a promising strategy.
  • Targeting both pathways may enhance treatment efficacy for resistant breast cancers.

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