Zhao, PeiZhu, YeziCheng, LiangLuo, Jun2019-07-242019-07-242019-01Zhao, P., Zhu, Y., Cheng, L., & Luo, J. (2019). Detection of androgen receptor (AR) and AR-V7 in small cell prostate carcinoma: Diagnostic and therapeutic implications. Asian journal of urology, 6(1), 109–113. doi:10.1016/j.ajur.2018.09.003https://hdl.handle.net/1805/19932Objective: Small cell prostate carcinoma (SCPC) is a rare and highly malignant subtype of prostate cancer. SCPC frequently lacks androgen receptor (AR) and prostate-specific antigen (PSA) expression, and often responds poorly to androgen deprivation therapy (ADT). AR splice variant-7 (AR-V7) is a truncated AR protein implicated in resistance to AR-targeting therapies. AR-V7 expression in castration-resistant prostate cancers has been evaluated extensively, and blood-based detection of AR-V7 has been associated with lack of response to abiraterone and enzalutamide. However, whether AR-V7 is expressed in SCPC is not known. Methods: Using validated antibodies, we performed immunohistochemistry (IHC) assay for the full-length AR (AR-FL) and (AR-V7) on post-ADT surgical SCPC specimens. Results: Seventy-five percent (9/12) of the specimens showed positive staining for the AR-FL with various intensities. Thirty-three percent (4/12) of the specimens showed positive staining for AR-V7. Among the specimens with positive AR-V7 staining, two samples displayed very weak staining, one sample showed weak-to-moderate staining, and one sample showed strong staining. All positive specimens displayed a heterogeneous pattern of AR-FL/AR-V7 staining. All specimens positive for AR-V7 were also positive for AR-FL. Conclusion: The study findings support the existence of measurable AR-FL and AR-V7 proteins in SCPC specimens. The results also have implications in detection of AR-V7 in specimens obtained through systemic sampling approaches such as circulating tumor cells. A positive AR-V7 finding by blood-based tests is not impossible in patients with SCPC who often demonstrate low PSA values.en-USAttribution-NonCommercial-NoDerivs 3.0 United StatesAndrogen receptorAndrogen receptor splice variant-7ImmunohistochemistrySmall cell prostate carcinomaArticle