A case of very elderly patient with multiple cervical metastases of salivary duct carcinoma successfully treated by anti-androgen and proton beam therapies

Abstract Objective The prognosis of salivary duct carcinoma (SDC) is reported to be very poor, worse than those of other salivary gland cancers. Previous immunohistochemical studies have demonstrated high expression of androgen receptor (AR) in SDC cases, suggesting that androgen deprivation therapy (ADT) may be effective for this disease. Methods & results A 90-year-old man with SDC from left buccal mucosa and multiple cervical lymph node metastases was treated with ADT. After 6 months of therapy, the tumor was markedly reduced on visual inspection, palpation, and positron emission tomography. No adverse events were noted. Subsequently, proton therapy was added, and a complete response was obtained. There has been no recurrence for 1.5 years since proton therapy was completed. Conclusions ADT should be considered as a therapeutic option for unresectable advanced SDC.