Total prostate and transition zone volumes, and transition zone index are poorly correlated with objective measures of clinical benign prostatic hyperplasia

Abstract

Purpose: We determined if total prostate volume, transition zone volume or transition zone index is correlated with the severity of clinical benign prostatic hyperplasia (BPH).

Materials and methods: A total of 93 men 52 to 85 years old, who were referred to a urology outpatient facility for treatment of clinical BPH, elevated serum prostate specific antigen or abnormal digital rectal examination, underwent measurement of total prostate and transition zone volume at transrectal ultrasonography. All men were requested to undergo uroflowmetry and complete the American Urological Association (AUA) symptom score.

Results: The pairwise correlations between AUA symptom score, versus total prostate and transition zone volumes and transition zone index were not statistically or clinically significant. A weak pairwise relationship was observed between peak flow rate versus total prostate volume (r2 = 0.160), transition zone volume (r2 = 0.156) and transition zone index (r2 = 0.147). The pairwise relationships between AUA symptom scores versus all prostate volumes were not statistically significant for subjects with mild (score 8 or less) or moderate to severe (score more than 8) symptoms.

Conclusions: Total prostate and transition zone volumes, and transition zone index are not directly related to AUA symptom score and only weakly related to peak flow rate. These findings provide further evidence that the total prostate, total BPH and relative BPH volumes are not useful determinants of the severity of clinical BPH.