A STUDY OF CORRELATIONSHIP BETWEEN THERAPEUTIC EFFICACY OF ANTI-ANDROGEN THERAPY IN PROSTATIC CANCER AND ANDROGEN RECEPTOR CONTENT OF PROSTATIC CANCER TISSUE
1984 Volume 75 Issue 8 Pages 1212-1224
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1984 Volume 75 Issue 8 Pages 1212-1224
The present study was undertaken to determine if the efficacy of a conventionally used anti-androgen therapy in prostatic cancer can be predicted using androgen receptor as an index.
Cytosol fractions and crude nuclear extract were prepared from hypertrophic and cancerous tissues of the prostate and the androgen receptor content was determined using a synthetic androgen, methyltrienolone (R1881), as the ligand.
A seven point Scatchard analysis was carried out on preparations from hypertrophic tissues, while a one point assay (single point determination) was performed on small amounts of needle biopsy specimens of cancer tissue. The results are summarized as follows:
1) The cytosol receptor content (as estimated in terms of NBS) was 31.2±2.8fmoles/mg protein (mean±S. E.) and 33.4±13.6fmoles/mg protein for cancerous tissue of the prostatic gland. The values were thus nearly equal, and the two types of prostatic tissue were considered remarkably androgen dependent.
2) A comparison of androgen receptor content between cytosol and crude nuclear extract of hypertrophic prostatic tissue showed that the value was higher for crude nuclear extract, a fact implying that androgens are actively taken up by the prostate.
3) In an attempt to investigate the correlationship between the androgen receptor content of prostatic cancer tissue and the efficacy of anti-androgen therapy, cytosol receptor content was correlated to responses to anti-androgen therapy.
Responders to anti-androgen therapy gave a value of 69.3±27.7fmoles/mg protein (mean±S. E.), while nonresponders to anti-androgen therapy showed a corresponding value of 17.4±15.7femoles/mg protein (mean±S. E.). There was a striking difference between the two groups.
Anti-androgen therapy tend to prove ineffective notably in those cases showing a cytosol receptor content below 10fmoles/mg protein. These results indicate the possible usefulness of androgen receptor contained in prostatic cancer tissue as an index for the selection of appropriate initial therapy for prostatic cancer.
