Salivary duct carcinoma: immunohistochemical profile of an aggressive salivary gland tumour.
BACKGROUND
Salivary duct carcinoma (SDC) is considered to be a distinct malignancy of the major salivary glands, because of its highly aggressive behaviour, and the high rate of recurrence, metastasis, and disease related death.


OBJECTIVE
To investigate expression of the proteins involved in the retinoblastoma (pRb) and p53 pathways, which control cell cycle progression at the G1/S checkpoint, and also expression of the c-erbB-2 oncoprotein in SDCs.


METHODS
Using a streptavidin-biotin method, five cases of SDC were evaluated immunohistochemically for the presence of cyclin D1, CDK4 (cyclin dependent kinase 4), p16 (CDK2A), pRb (retinoblastoma protein), E2F-1, p53, mdm2 (murine double minute 2), bcl-2, and the c-erbB-2 oncoprotein to determine whether there was a correlation between the expression of these proteins and patient outcome.


RESULTS
All of the cases showed deregulation of the pRb and p53 pathways. Of the five patients analysed, only the patient with longterm survival (10 years) was not positive for c-erbB-2 expression.


CONCLUSIONS
c-erbB-2 overexpression was associated with a poor prognosis. Aggressive behaviour, recurrence, and metastatic potential do not appear to be related to cell cycle deregulation, but seem to be associated with the c-erbB-2 oncoprotein, which is involved in matrix degradation and proteolitic activity, in addition to increases in vessel permeability, endothelial cell growth, proliferation, migration, and differentiation. There was a correlation between c-erbB-2 oncoprotein expression and aggressive behaviour in SDCs.
Etges
A
A
Oral Pathology, School of Dentistry, Federal University of Pelotas/UFP, Pelotas, Rio Grande do Sol, Brazil, CEP 96015.
Pinto
D S
DS
Kowalski
L P
LP
Soares
F A
FA
Araújo
V C
VC
D000368:Aged; D044584:Carcinoma, Ductal / Q000737:chemistry* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis*; D010307:Parotid Neoplasms / Q000737:chemistry* / Q000473:pathology; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D016160:Retinoblastoma Protein / Q000032:analysis; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
D009363:Neoplasm Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; D016160:Retinoblastoma Protein; D016159:Tumor Suppressor Protein p53