1706P - Anti-Androgen Therapy for the Patients with Recurrent and/or Metastatic Salivary Duct Carcinoma Expressing Androgen Receptors: A Retrospective Study

Abstract

ABSTRACT Background Salivary duct carcinoma (SDC) is one of the WHO classified histological types of salivary gland tumors (SGT) and consists of less than 10% among all the SGT. SDC is known as highly malignant with its aggressive clinical course, high rate of recurrence and metastasis and 2-3 years of median survival time. Up-front therapy is surgery, but treatment option is quite limited when it recurs and/or metastasis not being suitable for surgical resection. Androgen receptor (AR) is expressed in about 90% of SDC. Several reports suggest that AR would be a good candidate for treatment target for this entity. Patients and methods We conducted a retrospective analysis in patients with AR positive, recurrent and/or metastatic SDC treated anti-androgen therapy in our institution from January 1997 and April 2012. AR positivity was defined by immunohistochemistry (AR441, DAKO). Anti-androgen therapy was given as a single agent LH-RH analogue every four weeks until disease progression or intolerable adverse events. Responses to anti-androgen therapy were assessed according to RECIST. Results Eight patients were included. All were male. Median age was 57 years (range 40-76). Primary site was parotid gland in 7 and submandibular gland in 1. Initial clinical stage was II in 2, IVA in 5 and IVC in 1. All patients had received surgery for SDC prior to anti-androgen therapy. The patterns of relapse were locoregional recurrence in 4 and distant metastasis in all. Median number of cycles of anti-androgen therapy was 4 (range 2-10). No serious adverse event was seen. The best responses were PR in 2 and SD in 3, and median time of response duration was 4.6 months. After progression of anti-androgen therapy, all but one received chemotherapy included platinum compounds, taxanes and fluorouracil. Median overall survival time from receiving anti-androgen therapy was 22 months. Discussion and conclusion Anti-androgen therapy was well tolerated and demonstrated promising clinical activity for patients with recurrent and/or metastatic SDC. This might delay the start of chemotherapy and provide survival benefits, and this approach warrants further investigation. Disclosure All authors have declared no conflicts of interest.