Background: A multicenter, clinical trial investigated the effects of an interruption of antiandrogen therapy on subjective and objective clinical parameters in patients with benign prostatic hypertrophy (BPH).
Methods: Patients were given antiandrogen therapy with allylestrenol (50 mg/day) for 16 weeks. The medication was then withheld and the patients were carefully monitored for an additional 16 weeks. There were 34 BPH patients ranging in age from 55 to 82 years (mean, 66.1 years). The efficacy of allylestrenol was evaluated by its effects on prostate volume, maximum urinary flow rate (MFR), and symptom scores at the end of 16 weeks of treatment and then again at 32 weeks (16 weeks after cessation of therapy).
Results: Allylestrenol was effective in the treatment of BPH, and was still effective 16 weeks after the cessation of medication. The prostate volume did not change after treatment cessation nor did the total symptom score, but the MFR reversed to the pretreatment level. Serum testosterone (1.95 ng/mL), dihydrotestosterone, and gonadotropin levels decreased on therapy, but were completely reversed by the end of this study. A prostate needle biopsy revealed that after 16 weeks without therapy, some glands showed regressive glandular changes, while some glands showed slight hyperplastic changes of the secretory epithelium. Eight per cent of patients complained of loss of libido during this study.
Conclusions: Allylestrenol is an effective and safe medical treatment for patients with symptomatic BPH. Hormonal and histopathologic findings suggest that the prostate gland may regrow after discontinuation of medication.