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Updated: Aug 19, 2026

Assessment of Resistance to Tyrosine Kinase Inhibitors by an Interrogation of Signal Transduction Pathways by Antibody Arrays
07:42

Assessment of Resistance to Tyrosine Kinase Inhibitors by an Interrogation of Signal Transduction Pathways by Antibody Arrays

Published on: September 19, 2018

Type I receptor tyrosine kinases are associated with hormone escape in prostate cancer

John M S Bartlett1, Daniella Brawley, Ken Grigor

  • 1Division of Cancer Sciences and Molecular Pathology, University Department of Surgery, Level II Queen Elizabeth Building, Glasgow Royal Infirmary, Glasgow, G31 2ER, UK. J.M.Bartlett@clinmed.gla.ac.uk

The Journal of Pathology
|February 3, 2005
PubMed

Insights

Increased expression of EGFR or HER2 may drive prostate cancer relapse during hormone therapy. This finding suggests targeted therapies could improve outcomes for patients with androgen-independent prostate cancer.

Area of Science:

  • Oncology
  • Molecular Biology

Background:

  • Prostate cancer relapse during androgen withdrawal therapy is a major cause of mortality.
  • While androgen receptor mutations/amplifications explain some relapses, alternative mechanisms are involved in ~70% of cases.
  • Type I receptor tyrosine kinases are implicated in hormone escape.

Purpose of the Study:

  • To investigate the role of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) in prostate cancer hormone relapse.
  • To determine if EGFR/HER2 gene amplification or expression changes correlate with relapse and patient survival.

Main Methods:

  • Analyzed EGFR and HER2 gene amplification using fluorescence in situ hybridization (FISH).
  • Assessed EGFR and HER2 protein expression via immunohistochemistry (IHC).
  • Studied matched tumor pairs from 49 prostate cancer patients before and after hormone relapse.

Main Results:

  • No significant EGFR amplification was observed; low-level, heterogeneous HER2 amplification occurred in 6.5% of cases.
  • No strong correlation found between EGFR/HER2 gene copy number and protein expression.
  • Increased HER2 or EGFR expression was found in 24.5% of patients at hormone relapse, significantly reducing survival time (p = 0.0003).

Conclusions:

  • EGFR and HER2 gene amplification are not significant factors in prostate cancer relapse.
  • Increased EGFR/HER2 expression at hormone relapse may drive progression to androgen independence in ~25% of cases.
  • The EGFR/HER2 pathway represents a potential therapeutic target for androgen-independent prostate cancer.

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