Salivary ductal adenocarcinoma with complete response to androgen blockade

Salivary ductal adenocarcinomas make up about 9% of malignant salivary gland tumors and occur mostly in men older than 50 years, with a peak incidence in the sixth and seventh decades. It is the most aggressive of salivary gland tumors and is histologically similar to high-grade, invasive ductal carcinoma of the breast. In all, 65% of patients will die of the disease, and most will experience skin ulceration and nerve palsy.1 With such an aggressive clinical picture, the temptation for many oncologists and patients is to use aggressive cytotoxic chemotherapies. Considering the lack of large trials exploring treatment options in this less-common subtype of salivary gland carcinoma, practice guidelines also recommend the use of aggressive chemotherapies. Unlike other types of malignant cancers of the salivary glands, 70% to 90% of ductal adenocarcinomas express the androgen receptor (AR) by immunohistochemistry.2 †ere are reported cases of androgen deprivation therapy (ADT) as a successful treatment for salivary ductal adenocarcinomas that express the AR (Table). In 2003, Locati and colleagues reported the case of a man with salivary ductal adenocarcinomas who had a complete response with ADT.3 In 2016, the same group of authors published a retrospective analysis of 17 patients with recurrent or metastatic AR-positive salivary gland cancers who were treated with ADT and reported a 64.7% overall response rate among the patients.4 A 10-patient case series in the Netherlands demonstrated a 50% response rate to ADT plus bicalutamide, including a palliative eŽect in the form of pain relief.5 A retrospective analysis by Price and colleagues of 5 patients with AR-positive metastatic salivary duct adenocarcinoma showed a 60% response rate to a combination of leuprolide and bicalutamide.6