A clinicopathological study and prognostic factor analysis of 177 salivary duct carcinoma patients from The Netherlands

Abstract

Salivary duct carcinoma (SDC) is a subtype of salivary gland cancer with a dismal prognosis and a need for better prognostication and novel treatments. The aim of this national cohort study was to investigate clinical outcome, prognostic factors, androgen receptor (AR) and human epidermal growth factor receptor 2 (HER2) expression. SDC patients diagnosed between 1990 and 2014 were identified by the Nationwide Network and Registry of Histo‐ and Cytopathology in the Netherlands (PALGA). Subsequently, medical records were evaluated and pathological diagnoses reviewed. Data were analyzed for overall survival (OS), disease‐free survival (DFS), distant metastasis‐free survival (DMFS) and prognostic factors. AR was evaluated by immunohistochemistry (IHC), HER2 by IHC and fluorescent in‐situ hybridization. A total of 177 patients were included. The median age was 65 years, 75% were male. At diagnosis, 68% presented with lymph node metastases and 6% with distant metastases. Median OS, DFS and DMFS were 51, 23 and 26 months, respectively. In patients presenting without distant metastases, the absolute number of positive lymph nodes was associated with poor OS and DMFS in a multivariable analysis. AR and HER2 were positive in 161/168 (96%) and 44/153 (29%) tumors, respectively, and were not prognostic factors. SDC has a dismal prognosis with primary lymph node involvement in the majority of patients. The absolute number of lymph node metastases was found to be the only prognostic factor for DMFS and OS. AR expression and—to a lesser extent—HER2 expression hold promise for systemic treatment in the metastatic and eventually adjuvant setting.

Prediction of clinical benefit from androgen deprivation therapy in salivary duct carcinoma patients

“…Besides ADT, other treatment options are available for patients with R/M SDC. In the case of ERBB2 (HER2) gene amplification (29.4–46.4%), patients can be treated with docetaxel plus trastuzumab, showing an overall response rate of 70.2% and median PFS of 8.9 months . Double HER2 blockade with docetaxel–trastuzumab–pertuzumab or in second‐line with the antibody‐drug conjugate trastuzumab‐emtansine also showed promising results .…”

“…Salivary duct carcinoma (SDC) is an aggressive subtype of salivary gland cancer, which is often androgen receptor (AR) positive (66.7-96.4%). [1][2][3] Primary treatment consists of a tumor resection, most often in combination with a neck dissection and postoperative radiotherapy. Despite this extensive treatment, the 3-year disease-free survival (DFS) rate is only 27.7% in locally advanced patients.…”

Intensity Modulated Radiotherapy (IMRT) With Carbon Ion Boost in the Multimodal Treatment of Salivary Duct Carcinoma

“…Malignant salivary gland tumors (MSGT) have an estimated annual incidence rate of 1 to 1.2 per 100,000 (4). SDC account for approximately 1% to 3% of all malignant salivary gland tumors and mostly occur during the fifth to seventh decade of life; men are predominantly affected (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). Current treatment options include surgery, systemic therapy, radiation and targeted therapy.…”

A case of carcinoma ex pleomorphic adenoma arising from multinodular pleomorphic adenoma of the buccal region

“…Meanwhile, the investigation for SDC prognosis in the minor salivary glands may be insufficient . HER2 has been reported to be positive in approximately 40% of SDC, and the overexpression of HER2 and tumor protein p53 is likely associated with the poor clinical course of SDC …”

“…Meanwhile, the investigation for SDC prognosis in the minor salivary glands may be insufficient. 21 HER2 has been reported to be positive in approximately 40% of SDC, 22,23…”