HER2 oncogene amplification in extramammary Paget's disease.
OBJECTIVE
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.


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.
Tanskanen
M
M
Department of Pathology, Helsinki University and Helsinki University Central Hospital, Finland. maarit.tanskanen@helsinki.fi
Jahkola
T
T
Asko-Seljavaara
S
S
Jalkanen
J
J
Isola
J
J
D000368:Aged; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D005260:Female; D005784:Gene Amplification / Q000235:genetics*; D018734:Genes, erbB-2 / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D010145:Paget Disease, Extramammary / Q000235:genetics* / Q000378:metabolism / Q000556:secondary; D010144:Paget's Disease, Mammary / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D012878:Skin Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
D018719:Erb-b2 Receptor Tyrosine Kinases