Endocrine resistance signaling pathways

Endocrine resistance signaling pathways refer to a complex network of molecular mechanisms that enable hormone-dependent cancer cells, particularly in breast and prostate cancers, to survive and grow despite treatment with endocrine therapies. These pathways facilitate resistance through various means, including the acquisition of mutations in hormone receptors (such as ESR1), the upregulation of growth factor receptors like HER2 and EGFR, and the hyperactivation of downstream signaling cascades such as the PI3K/AKT/mTOR and MAPK/ERK pathways. These alterations often lead to ligand-independent activation of nuclear receptors or provide alternative proliferative signals that bypass the need for hormonal stimulation. In clinical practice, overcoming this resistance involves the use of combination therapies that target both the primary hormone receptor and the secondary escape pathways. For example, CDK4/6 inhibitors, PI3K inhibitors, and mTOR inhibitors are frequently used alongside tamoxifen or aromatase inhibitors to enhance efficacy and delay disease progression. Understanding these pathways is essential for identifying biomarkers of resistance and developing personalized therapeutic strategies to improve outcomes for patients with advanced or metastatic endocrine-related malignancies.

Other names

Hormone resistance pathwaysAntiestrogen resistance mechanismsCastration resistance signalingAcquired endocrine resistance pathway

Drugs targeting this network function by inhibiting specific signaling nodes that allow cancer cells to bypass hormonal control. This includes direct antagonism or degradation of hormone receptors, inhibition of cell cycle regulators (CDK4/6), and blockade of alternate survival cascades such as the PI3K/AKT/mTOR and MAPK/ERK pathways to restore therapeutic sensitivity.