Expression of HER-2/neu gene and protein in salivary duct carcinomas of parotid gland as revealed by fluorescence in-situ hybridization and immunohistochemistry.
OBJECTIVE
Salivary duct carcinoma is a highly malignant salivary gland tumour with aggressive clinical behaviour, characterized by histological resemblance to invasive ductal carcinoma of the breast. Amplification of HER-2/neu oncogene and over-expression of its gene product have both prognostic and therapeutic implications in breast cancer. Recent report on salivary duct carcinomas for HER-2/neu using immunohistochemistry (IHC) has shown over-expression in most cases. However, correlation between IHC and molecular genetic analysis of HER-2/neu in salivary duct carcinoma has not yet been performed.


RESULTS
We have now evaluated 11 cases of salivary duct carcinomas for HER-2/neu status using IHC and fluorescent in-situ hybridization (FISH). To our knowledge, this is the first molecular genetic analysis of HER-2/neu in salivary duct carcinoma.


CONCLUSIONS
In immunohistochemistry, over-expression of HER-2/neu protein was identified as distinct membrane staining in most carcinoma cells in all our salivary duct carcinoma cases, while only four cases revealed an amplification of HER-2/neu gene by means of FISH analysis. Both amplified and non-amplified salivary duct carcinomas with strong immunohistochemical staining for HER-2/neu protein were associated with poor clinical outcome for the patients. Apparently, HER-2/neu protein over-expression could also be controlled by mechanisms other than gene amplification. In the group of salivary gland tumours other than salivary duct carcinoma, strong over-expression was detected only in three cases of carcinoma ex pleomorphic adenoma. Thus, over-expression of HER-2/neu protein is also a useful marker of malignant transformation in pleomorphic adenomas.
Skálová
A
A
Department of Pathology, Medical Faculty, Charles University, Plzen, Czech Republic. skalova@fnplzen.cz
Stárek
I
I
Vanecek
T
T
Kucerová
V
V
Plank
L
L
Szépe
P
P
Di Palma
S
S
Leivo
I
I
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism* / Q000556:secondary; D005260:Female; D005784:Gene Amplification; D015870:Gene Expression / Q000235:genetics*; D018734:Genes, erbB-2; D006801:Humans; D007124:Immunoenzyme Techniques; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D010307:Parotid Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D018987:Salivary Ducts / Q000473:pathology
D018719:Erb-b2 Receptor Tyrosine Kinases