We performed a phenotypic assessment of GR and AR localization and expression and determined in the association with clinicopathologic factors in 67 primary SDCs.
The 3 SDCs that expressed the highest levels of AR-V7 were all from female patients; one of them expressed a significant amount of AR-V7 and barely detectable full-length AR transcripts by reverse-transcription polymerase chain reaction.
We conclude that comprehensive molecular profiling of SDCs can guide the selection of patients for targeted therapies involving AR, HER2, PD-L1, mitogen-activated protein kinase, and PIK3CA pathways.
Androgen deprivation therapy has demonstrated efficacy in cases of salivary duct carcinoma (SDC) and high-grade adenocarcinoma not otherwise specified (NOS) that express androgen receptor.
A total of 28 consecutive, surgically resected, de novo SDC cases were selected after evaluating histology and immunohistochemical expression of androgen receptor.
Only in a minority (20%) of patients, the preoperative diagnosis of SDC was raised due to positive immunohistochemical staining for the androgen receptor (AR) on cytology.
Salivary duct carcinoma (SDC) is an uncommon, aggressive tumour that, histologically, resembles high-grade mammary ductal carcinoma, and is characterised by the expression of androgen receptor (AR).
The typical molecular biological profile with high human epidermal growth factor receptor 2 and androgen receptor expression is increasingly successfully exploited in clinical trials for advanced SDC.
Therefore, similar to AR-positive prostate cancer (PCa), AR-positive SDC patients benefit from androgen deprivation therapy and, after progression on ADT, might take advantage of Ra dichloride, a radiopharmaceutical approved for the treatment of castration-resistant PCa with symptomatic bone disease.
Our study provides new detailed information on the molecular and structural alterations associated with AR gene activation in SDC and sheds more light on the putative functional role of AR in SDC cells.
Our study indicates that: i) SDC may share some genetic alterations with IDC, ii) high AR expression in SDC may play a role in tumor progression, and iii) p53 overexpression and DNA aneuploidy in both entities reflect their aggressive behavior.