Standardized assessment to enhance the diagnostic value of prostate volume; Part II: Correlation with prostate-specific antigen levels

Population Standards of Prostate Specific Antigen Values in Men over 40: Community Based Study in Turkey

OBJECTIVE

To determine the prostate specific antigen (PSA) population standards of a cluster of Turkish men with no clinical evidence of prostate cancer.

PATIENTS AND METHODS

We evaluated PSA values of the men who were living in a well-defined, rural district of Western Anatolia. Two hundred fifty-seven men agreed to participate in this population-based study. They underwent clinical examination, transrectal ultrasonography and serum PSA measurement. The association between serum PSA and age, prostate volume and age, PSA and prostate volume, and PSA density (PSAD) and age were assessed. Distributions of serum PSA levels, prostate volumes (PV), and PSAD values as a function of age were generated.

RESULTS

The upper limit of normal PSA concentration were 4.51 ng/ml for men aged 40-49 years, 4.36 ng/ml for 50-59 years, 6.17 ng/ml for 60-69 years, and 10.18 ng/ml for over 70 years. The upper limit of normal (95th percentile) for the serum PSA concentration increased with age. Across the entire age range, no correlation was found between the serum PSA concentrations and age while significant correlation was found between serum PSA concentration and prostate volume.

CONCLUSION

In this present study, the PSA values in different age intervals showed higher than those observed in previous studies. The PSA values are mainly affected by prostate volume rather than age.

Serum prostate-specific antigen as a predictor of prostate volume in men with benign prostatic hyperplasia

OBJECTIVES

To assess the utility of prostate-specific antigen (PSA) as a predictor of prostate volume by characterizing the relationship between prostate volume and serum PSA in men with symptomatic benign prostatic hyperplasia (BPH) and no evidence of prostate cancer, stratified by decade of life.

METHODS

Placebo-controlled multicenter trials in patients with BPH and a safety study in normal young men provided baseline measurements of serum PSA and prostate volume. The analyses included patients with a baseline prostate volume measured by either transrectal ultrasound (TRUS) or magnetic resonance imaging and baseline serum PSA. A common central laboratory was used for all but one of the individual studies; both laboratories used the Hybritech method. Patients 80 years of age or older were excluded. Patients with a baseline serum PSA greater than 10 ng/mL were excluded to reduce the likelihood of including occult prostate cancer cases. The patients in the BPH trials were screened at baseline by digital rectal examination (DRE) and serum PSA. Those with suspicious findings underwent TRUS-guided biopsy; only patients with negative biopsies are included in these analyses.

RESULTS

The analyses included 4627 patients, 4448 from the BPH trials and 179 from the safety study. The men in the BPH trials were older (mean age+SE, 63.7+0.10 years) than the men in the safety study (mean age + SE, 30.8+/-0.43), had larger prostates (mean volume+/-SE, 43.7+/-0.38 mL versus 26.3+/-0.49 mL in the safety study), and had higher serum PSA values (mean+/-SE, 2.6+/-0.03 ng/mL versus 0.7+/-0.39 ng/mL in the safety study). The relationship between prostate volume and serum PSA was evaluated using only the BPH trial data. Prostate volume and serum PSA have an age-dependent log-linear relationship (ie, their logarithms are linearly related, and the parameters of the relationship depend on age). Older men tend to have a steeper rate of increase in prostate volume with increasing serum PSA (P < 0.00 for differences between slopes), and there was a slight tendency for PSA density to increase with age. Receiver operating characteristic (ROC) curves were constructed to evaluate the ability of serum PSA to predict threshold prostate sizes in men with BPH. The ROC curve analyses revealed that PSA had good predictive value for assessing prostate volume, with areas under the curve ranging from 0.76 to 0.78 for various prostate volume cutoff points (30, 40, and 50 mL). Conclusions. Prostate volume is strongly related to serum PSA in men with BPH and no evidence of prostate cancer, and the relationship depends on age. Since treatment outcome or risk of long-term complications depend on baseline prostate volume, serum PSA can estimate the degree of prostate enlargement sufficiently accurately to be useful for therapeutic decision making. To achieve a specificity of 70% while maintaining a sensitivity between 65% and 70%, approximate age-specific criteria for detecting men with prostate glands exceeding 40 mL are PSA > 1.6 ng/mL, >2.0 ng/mL, and >2.3 ng/mL for men with BPH in their 50s, 60s, and 70s, respectively.

Standardized assessment to enhance the diagnostic value of prostate volume; Part I: Morphometry in patients with lower urinary tract symptoms

BACKGROUND

The diagnostic value of prostate volume results has been evaluated in patients with prostate problems of benign cause.

METHODS

For 247 patients, automated volume results were compared to manual results of planimetric reference volume and of the classical ellipsoid formula. Also, transition zone volume was estimated and growth curves of the prostate and prostate dimensions over age were investigated.

RESULTS

Application of automated volume determination gives accurate results compared to the reference volume (Pearson correlation, R = 0.938). The ellipsoid volume results were slightly less correlated (R = 0.921). Average growth of the entire prostate was 1.7% per year, for the transition zone the growth was 4.3%. Compared to growth rates for a community-based population, comparable growth rates were found for our group that had higher mean prostate volume.

CONCLUSIONS

The results indicate that the age of onset of volume growth is the determining factor in developing benign prostate enlargement not a change in growth rate.