Androgen receptor heterogeneity in human prostatic carcinomas visualized by immunohistochemistry.

Expression of the human androgen receptor was examined in 26 primary prostatic carcinomas by immunohistochemical staining with a polyclonal antibody reactive with the N-terminal domain of the human androgen receptor. Eighteen carcinomas showed homogeneous staining for the androgen receptor, whereas in seven cases a considerable heterogeneity in expression of the receptor was found. In one case, only a very limited number of immunoreactive tumour cells were detected. Comparison of androgen receptor expression with the tumour grading score, according to the MD Anderson grading system, revealed that the proportion of immunostained tumour cells and--to a lesser extent--the intensity of immunostaining were decreased in the more aggressive (grade III) tumours. The use of immunohistochemistry for detection of expression of androgen receptor in prostatic carcinomas may become a new and sensitive method for predicting prostatic tumour behaviour under hormonal therapy and prognosis.