Abstract
Salivary duct carcinoma (SDC) is a rare and aggressive tumor of the salivary glands. An effective treatment for metastatic SDC has not been established. A case of metastatic SDC in which complete response was achieved with bicalutamide is presented. A 66-year-old man with an enlarged left subaural mass was diagnosed as having left parotid cancer (T4aN0M0). The patient underwent a total parotidectomy with complete facial nerve resection and upper neck dissection, and the pathological diagnosis was SDC overexpressing androgen receptor. He received localized radiotherapy of 66 Gy as a single fraction per day for 33 days after the operation. Seven months after surgery, computerized tomography (CT) showed multiple lung metastases. The lung nodules continued to increase in size, and the patient was prescribed oral bicalutamide (80 mg once daily). After 2 months of bicalutamide treatment, the lung nodules decreased in size. After 8 months, almost all lung metastases decreased more than 30% in size, and the patient was judged to have a partial response (PR). After 14 months, practically all lung metastases disappeared, and the patient was judged to have a complete response (CR). Five months after the commencement of treatment, the patient complained of grade 2 gynecomastia (Common Terminology Criteria for Adverse Events, version 4.0). Three years since the development of metastases to the lung, the patient is now doing well without recurrence of the disease. Bicalutamide monotherapy is safe and should be considered for patients with androgen receptor-positive salivary duct carcinoma.
