Salivary duct carcinoma - A highly aggressive salivary gland tumor with HER-2/neu oncoprotein overexpression

Salivary duct carcinoma (SDC) is a highly malignant salivary gland tumor wi th aggressive clinical behavior, and is characterized by its histological r esemblance to invasive ductal carcinoma of the breast. Overexpression and/o r amplification of proto-oncogene Her2/neu has been shown to influence both prognosis and treatment of breast cancer. Since salivary duct carcinoma an d ductal breast carcinoma share many common characteristics, HER2/neu overe xpression might also be important in SDC. However, data on the expression o f c-erbB2/HER2/neu in salivary gland tumors are still scarce. Therefore, we have evaluated 15 cases of salivary duct carcinomas (SDC) for HER2/neu ove rexpression using immunohistochemistry with the HercepTest. Overexpression, identified as strong or moderate membrane immunostaining, was observed in all but one case of SDC in most neoplastic cells. Thus, our study suggests that anti-HER2/neu therapy with Herceptin is beneficial for patients with a ggressive salivary duct carcinoma.