Androgen Receptor (SP107)

Qualitative and quantitative alterations of androgen receptor expression in prostatic carcinomas and their possible implications for tumor progression and treatment are therefore of diagnostic and research interest. Findings in prostatic tumor cell lines of rat and human origin suggest that reduction of androgen receptor protein expression is accompanied by an increase in tumor aggressiveness. However, immunohistochemical analysis and binding assays have demonstrated the presence of androgen receptors in all histological types of prostatic carcinoma and in both therapy-responsive as well as therapy-unresponsive tumors.

Most of the immunohistochemical studies of androgen receptors have been related to prostatic carcinoma and experimental animals. Patients with 48% or more androgen receptor-positive cells had statistically significant better outcome in terms of both progression-free and cause-specific survival. Another study suggested that prior to therapy, androgen receptor expression alone is not related to prognosis of hormonally treated prostate cancer; however, when combined with bcl-2 expression, it acts as an independent prognostic factor for clinical progression.

The variability of androgen receptor protein content per unit nuclear area has been shown to increase with increasing histological grade, suggesting that this variability might account for the response to endocrine therapy in high grade tumors. The extent of heterogeneity of androgen receptor expression may be a useful indicator of response to hormonal therapy.1-5