Combined androgen deprivation therapy in recurrent androgen-receptor-positive salivary duct carcinoma - a case report and review of the literature.

Salivary duct carcinoma (SDC) is a rare and highly aggressive neoplasm of the salivary glands associated with high rates of local and distant recurrence and poor overall survival. We present a patient with SDC, who relapsed despite extensive multimodal therapy including surgery, postoperative radiochemotherapy, and heavy ion therapy. In the recurrent setting, immunohistochemical analysis confirmed androgen receptor positivity, prompting initiation of combined androgen deprivation therapy (ADT), which resulted in a fast and durable remission of the local tumor now lasting for 26 months. Analyzing the histopathologic specimens of all SDC patients treated at our department since 2009, we found significant AR expression in all patients. This is in line with other reports found in current literature and indicates AR positivity as a consistent feature of SDC, supporting ADT as a viable therapeutic option for SDC.