Purpose: We attempted to determine the clinical and biological characteristics of familial benign prostatic hyperplasia (BPH).
Materials and methods: Urinary flow rate, prostate size, symptom score, serum prostate specific antigen, testosterone and dihydrotestosterone were measured in subjects who participated in the nationwide Merck phase III finasteride clinical trial. Findings in the 69 men with familial BPH (3 or more family members with BPH, including the proband) were compared to those in the 345 with no family history of BPH. Logistic regression was used to detect relationships between familial BPH, and these variables before and after 5 alpha-reductase inhibition with finasteride.
Results: Familial BPH was characterized by large prostate size. Mean prostate volume in men with familial and sporadic BPH was 82.7 and 55.5 ml., respectively (p < 0.001). Other clinical findings, including serum androgen levels and response to finasteride, were similar in familial and sporadic BPH. The frequency of familial BPH in patients with prostate size in the largest and smallest deciles was 46 and 13%, respectively.
Conclusions: Familial BPH in this group of patients was associated with large prostate size, normal serum androgen levels and normal response to 5 alpha-reductase inhibition. A genetic factor responsible for familial BPH may exert its influence through androgen independent control of prostatic growth.