Nuclear androgen receptor content in biopsy specimens from histologically normal, hyperplastic, and cancerous human...

Androgen receptors (ARn) were assayed in nuclear extracts of prostatic biopsies from 60 patients with benign prostatic hyperplasia (BPH) and 82 patients with prostatic cancer (PC), with an exchange assay using heparin extraction, labelling with 3H-R1881, and protamine sulphate precipitation. The content of ARn of BPH biopsies (38 +/- 34 fmol/mg protein [mean +/- SD]; n = 70) was not different from that of PC biopsies (39 +/- 32 fmol/mg protein; n = 115). Biopsies showing essentially normal prostatic tissue had a lower ARn content (12 +/- 13 fmol/mg protein; n = 6). The content of ARn was independent of the age of the patient and of the histological grade of the carcinomas. A considerable variation in ARn content within tumors of individual patients was found, indicating that ARn are not uniformly distributed over prostatic tissue; ie, cells with high and low receptor content may coexist in different proportions in different regions of the prostate. Therefore, assays on multiple biopsies may be required for a proper estimation of the mean receptor content. The question remains, however, whether the behavior of the tumor is adequately predicted by the mean receptor level or, for instance, by the region with the lowest receptor content.