Salivary Duct Carcinoma of the Parotid Gland: Is Adjuvant HER-2–Targeted Therapy Required?

Purpose Salivary duct carcinoma (SDC) of the parotid gland is a highly aggressive and uncommon tumor. Overexpression of human epidermal growth factor receptor 2 (HER-2) is characteristic of SDC. HER-2 overexpression is considered a poor prognostic marker for SDC, and anti–HER-2 therapy has been suggested as a therapeutic option. Materials and Methods Two patients with SDC were analyzed for HER-2 overexpression and gene amplification using immunohistochemistry and fluorescence in situ hybridization. Results In 1 patient, no expression of HER-2 was found. In the other patient, HER-2 was demonstrated. The patient with HER-2 overexpression had a worse prognosis, and trastuzumab proved to be an effective treatment. Conclusions The present results have also suggested that HER-2 overexpression is associated with a poor prognosis. Therefore, HER-2 status should be evaluated at least in the presence of advanced SDC, and targeted therapy should be considered in the adjuvant setting.