Comparison of androgen-independent growth and androgen-dependent growth in BPH and cancer tissue from the same radical prostatectomies in sponge-gel matrix histoculture.

BACKGROUND

In order to determine androgen sensitivities of prostate cancer and benign prostatic hypertrophy (BPH) tissues from the same patient in vitro, we used a histoculture technique to measure androgen-independent and androgen-dependent growth and compared them in paired specimens of BPH and prostate cancer from 23 radical prostatectomies. Both androgen-independent growth and androgen-dependent growth are measures of important biological characteristics of benign and malignant prostate tissue.

METHODS

The effect of hydroxyflutamide and antiandrogens on dihydrotestosterone (DHT)-stimulated incorporation of 3H-thymidine into both paired specimens of BPH and cancer was utilized to measure androgen-independent and androgen-dependent growth. The percentage decrease in 3H-thymidine incorporation/microgram protein in the flutamide-treated specimen compared to the DHT-treated specimen represented androgen-dependent growth. Residual 3H-thymidine incorporation/microgram protein during hydroxyflutamide administration represented androgen-independent growth.

RESULTS

Androgen-independent growth was significantly greater (P = 0.015) in the BPH compared to the cancer paired tissue. Androgen-dependent growth was significantly higher in 23 paired specimens of cancer compared to BPH (P < 0.03).

CONCLUSIONS

In paired specimens of BPH and prostate cancer from the same radical prostatectomy specimen, androgen-independent growth appeared greater in BPH compared to cancer specimens; androgen-dependent growth, however, was greater in prostate cancer than in BPH. There was no correlation of either growth parameter with Gleason tumor grade. Future clinical correlations will indicate whether either growth parameter represents an important prognostic factor for prostate cancer aggressiveness stimulated 3H-thymidine incorporation into DNA.