Objectives: To study, in a selected series of patients, whether the peripheral/central zone volumes also change with age. The reported normal total prostate volume in the third decade seems not to exceed 25 to 30 cm(3). Benign prostatic hyperplasia is generally accepted to originate in the transition zone and periurethral tissue, which accordingly show substantial growth with age.
Methods: From January 1997 through December 2000, we performed transrectal ultrasound volume measurements of the different prostate zones in patients admitted for suspected prostate cancer. The information was registered according to a prospectively designed protocol. A total of 872 patients were examined, of whom 360 shown to have prostate cancer were excluded. Two more patients were excluded because of missing volume data, leaving 510 patients with noncancerous prostates for inclusion in this study.
Results: The mean age was 62.8 years and the mean total prostate-specific antigen level was 9.8 microg/L. It was found that 64.9% (331 of 510) had a peripheral/central zone volume larger than 30 cm(3), indicating that some form of growth had occurred also in this zone. A weak but significant correlation was found between age and the peripheral/central zone volume.
Conclusions: The results of our study indicate that the peripheral/central zone may contribute to the benign growth of the prostate gland in men younger than 70 years old with slightly elevated total prostate-specific antigen levels.