HER2 oncogene amplification in extramammary Paget's disease

Histopathology. 2003 Jun;42(6):575-9. doi: 10.1046/j.1365-2559.2003.01648.x.


Aims: To study HER2 oncogene amplification and over-expression in skin samples of 23 patients with extramammary Paget's disease (EMP). EMP is a rare intra-epidermal adenocarcinoma, which has been reported to over-express the HER2 oncoprotein.

Methods and results: HER2 gene amplification, detected by chromogenic in-situ hybridization, was found in 43% (10/23) of the lesions. HER2 protein over-expression (3+ immunostaining intensity) was found in 12 tumours (52%), including all 10 tumours with gene amplification. Two tumours showed low-level (2+) HER2 immunostaining. Mammary Paget's lesions, which were used as controls, showed HER2 amplification and over-expression in all 10 cases studied.

Conclusions: These results indicate that HER-2 protein over-expression in EMP is common and due exclusively to gene amplification. They open up the possibility of HER2-targetted immunotherapy for patients with HER2+ disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Breast Neoplasms / genetics
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Female
  • Gene Amplification / genetics*
  • Genes, erbB-2 / genetics*
  • Humans
  • Immunohistochemistry
  • In Situ Hybridization
  • Male
  • Middle Aged
  • Paget Disease, Extramammary / genetics*
  • Paget Disease, Extramammary / metabolism
  • Paget Disease, Extramammary / secondary
  • Paget's Disease, Mammary / genetics
  • Paget's Disease, Mammary / metabolism
  • Paget's Disease, Mammary / pathology
  • Receptor, ErbB-2 / metabolism
  • Skin Neoplasms / genetics*
  • Skin Neoplasms / metabolism
  • Skin Neoplasms / pathology


  • Receptor, ErbB-2