Antiandrogene und LH-RH-Agonisten: Endokrinologie in der Initialphase ihrer Anwendung

Influence of different types of antiandrogens on luteinizing hormone-releasing hormone analogue-induced testosterone surge in patients with metastatic carcinoma of the prostate

The long-term effect of the luteinizing hormone-releasing hormone analogue-induced initial testosterone surge in the treatment of patients with metastatic carcinoma of the prostate still is unknown. However, acute worsening of the disease has been reported in up to 10% of the patients. To prevent such tumor flare we investigated the endocrinological effects of different types of antiandrogens administered in addition to a luteinizing hormone-releasing hormone analogue. Patients with newly diagnosed metastatic prostate cancer were pre-treated with either the steroidal antiandrogen cyproterone acetate (6) or the nonsteroidal antiandrogen flutamide (5) for 1 week before the initial injection of the depot luteinizing hormone-releasing hormone analogue Zoladex. In another 5 patients flutamide was first given 24 hours before Zoladex therapy was started. Luteinizing hormone, testosterone and prostatic acid phosphatase during month 1 of luteinizing hormone-releasing hormone analogue therapy were compared to data obtained in 5 patients treated by Zoladex alone. Only pre-treatment with cyproterone acetate was capable of preventing the Zoladex-induced testosterone surge. However, both pre-treatment regimens with either cyproterone acetate or flutamide for 1 week prevented an initial increase in prostatic acid phosphatase beyond pre-treatment levels in all patients. In contrast, in 4 of 5 patients treated with Zoladex alone and in 2 of 5 pre-treated with flutamide for 1 day an initial increase in prostatic acid phosphatase beyond the pre-treatment values was seen. Our data indicate that pre-treatment with flutamide for only 1 day may not be sufficient to prevent a luteinizing hormone-releasing hormone analogue-induced tumor flare in all cases.

Prostatic cancer--survey of hormonal treatment in Europe

Prostatic cancer is often locally advanced or metastatic when diagnosed, making surgical removal and radiotherapy ineffective treatments. Alternative therapy involves androgen deprivation because prostatic cancer is known to be androgen-dependent. Orchidectomy has proved effective but other methods of reducing androgen concentrations have also been developed. Oestrogens have proved effective, as have progestogens, and both steriodal and non-steroidal anti-androgens have been extensively studied. Another possible treatment is the use of inhibitors of androgen metabolism (aromatase and 5 alpha-reductase). Luteinizing hormone releasing hormone analogues, which act as antagonists or agonists, have been shown to have efficacies comparable to those of other therapies. Adrenal suppression has provided a useful alternative to adrenalectomy, particularly because of the high morbidity rate of surgery in elderly patients. Complete androgen withdrawal using an anti-androgen in association with surgical or chemical castration may be a more superior treatment. Another possible approach is the use of somatostatin analogues, which have been shown to inhibit the growth of animal prostatic cancer cells.

Effect of cyproterone acetate in comparison to flutamide and megestrol acetate on the ventral prostate, seminal vesicle, and adrenal glands of adult male rats

Cyproterone acetate (CPA) has a stronger inhibitory effect than megestrol acetate (MGA) and flutamide (FL) on the prostate and seminal vesicle of intact adult rats. Only in the clinically irrelevant regimen of castration and simultaneous androgen substitution is FL as a competitive androgen antagonist more potent than CPA and MGA. The latter inhibit complete involution of the ventral prostate but not of the seminal vesicle of castrated adult rats. This effect is very small in magnitude, cannot be increased by the use of higher doses, and is only reduced but not blocked by simultaneous treatment with high doses of FL. Further, CPA is unable to stimulate proliferation or restore the function of the involuted rat prostate. CPA and MGA inhibit adrenal weight in rats, thus indicating a glucocorticoidlike activity in this species. A critical review of all available data on the antiandrogenic, glucocorticoidlike, and possible paradoxical androgenlike activities of CPA in different animal experiments has no important bearing on the clinical effectiveness of CPA in the treatment of prostatic cancer.