From the Guidelines
The normal prostate volume in adult men is typically considered to be less than 30cc, as volumes greater than 30cc may indicate benign prostatic hyperplasia (BPH) and are often used as a threshold for treatment with 5-alpha reductase inhibitors (5-ARIs) 1.
Prostate Volume and Age
Prostate volume varies with age, with gradual enlargement occurring as men get older.
- Young adult men (20-30 years) usually have prostate volumes of 15-25 cc.
- Men in their 60s may have volumes of 25-35 cc that are still considered normal.
Measurement of Prostate Volume
Prostate volume is typically measured using transrectal ultrasound (TRUS) or MRI imaging.
- Enlargement beyond the normal range may indicate BPH, which becomes increasingly common after age 50.
- The prostate naturally grows throughout a man's life due to hormonal influences, particularly dihydrotestosterone (DHT), which stimulates prostate cell growth.
Importance of Prostate Volume
While prostate volume alone doesn't necessarily indicate disease, significant enlargement can cause urinary symptoms by compressing the urethra.
- Regular prostate examinations are recommended for men over 50 to monitor prostate size and health.
- A minimum prostate volume of >30cc or PSA >1.5ng/mL is necessary for a reliable 5-ARI response, but the larger the gland, the more pronounced the effects 1.
From the FDA Drug Label
Mean prostate volume at baseline ranged between 40 to 50 cc. The mean prostate volume as measured by transrectal ultrasound was 36.3 mL (±20. 1 mL). Prostate volume was ≤20 mL in 16% of patients, ≥50 mL in 18% of patients and between 21 and 49 mL in 66% of patients
The normal prostate volume is not explicitly stated in the provided text. However, based on the information given, the average baseline prostate volume ranged from 40 to 50 cc and the mean prostate volume as measured by transrectal ultrasound was 36.3 mL. It is also noted that prostate volume varied among patients, with 16% having a volume ≤20 mL, 18% having a volume ≥50 mL, and 66% having a volume between 21 and 49 mL 2.
From the Research
Prostate Volume Estimation
- The normal prostate volume can be estimated using various methods, including digital rectal examination (DRE), serum prostate specific antigen (PSA), and transrectal ultrasonometry (TRUS) 3.
- A study found that DRE has limited value in estimating prostate volume, but is good in identifying very large prostates (>50 cc) 3.
- Serum PSA performs reasonably well in estimating prostate volume, with an area under the curve (AUC) of 0.79,0.86, and 0.92 for volumes above 30,40, and 50 cc, respectively 3.
Prostate Volume Ranges
- A normal prostate is generally defined as less than 20 mL, with no intravesical prostatic protrusion (IPP) to distort the normal funneling bladder neck on transabdominal ultrasound (TAUS) 4.
- The mean and median prostate volumes in Ethiopian adults were found to be 42 cc and 35 cc, respectively, with a range of 7.1 cc to 169 cc 5.
- A study found that prostate volume increases with age, with a peak volume seen in the seventh decade of life 5.
Clinical Applications
- The estimation of prostate volume is important in the management of benign prostatic hyperplasia (BPH) and the selection of appropriate treatment 6.
- DRE may be sufficient to identify suitable patients for 5-alpha-reductase inhibitor (5-ARI) therapy, but transrectal ultrasound (TRUS) may be required for prostate volumes between 25 cc and 30 cc and above 80 cc 6.
- There is a direct relationship between prostate gland volume and PSA value, as well as a cancer value threshold 7.