Androgen receptor immunohistochemistry in genitourinary neoplasms

Abstract

Purpose: Androgen receptor (AR) is a recognized immunohistochemical marker of prostate cancer. However, the sensitivity and specificity of AR for prostate cancer in the setting of other genitourinary neoplasms has not been rigorously studied.

Methods: We employed tissue microarrays containing prostate carcinomas, urothelial carcinomas, renal cell carcinomas, and testicular neoplasms. Slides were stained immunohistochemically for AR.

Results: Androgen receptor was positive in 95% of prostate carcinomas (n=230), but 19% of invasive urothelial carcinomas of the bladder (n=190) and 33% of non-invasive bladder urothelial carcinomas were also AR positive (N=107). Furthermore, 16% of renal pelvis urothelial carcinomas (n=43) were positive. Of primary renal cell carcinomas, 19% were AR positive (n=307). From a metastatic renal cell carcinoma cohort, 28% of metastases were AR positive (N=126). Six percent of non-teratomatous testicular germ cell tumors stained for AR (n=103).

Conclusions: Our data show that the sensitivity of AR immunohistochemistry for prostate cancer is 94.8%. However, the specificity of AR is only 81.4%, among our cohort of invasive genitourinary tumors. Thus, we find the specificity of AR suboptimal, yet AR may remain useful as a component of an immunostain panel.