Prospective evaluation of prostate cancer detection by prostate-specific antigen-related parameters

Any Correlation Between Prostate Volume and Incidence of Prostate Cancer: A Review of Reported Data for the Last Thirty Years

PURPOSE

Prostate cancer (PCa) is the most common non-skin cancer in men worldwide and more than 80% of men with PCa also have histo-anatomical findings of benign prostate hyperplasia (BPH). It is well documented that BPH develops in the transition zone (TZ), whereas 80-85% of PCa originates in the peripheral zone (PZ) of the prostate. Possible causal links between both disease entities are controversially discussed in the current literature. Some studies have reported that larger prostates have a decreased incidence of PCa compared to smaller prostates. The purpose of this systematic review is to comprehensively summarize studies analyzing any association between prostate gland volume and incidence of PCa.

METHODS

A thorough literature review was performed between 01.01.1990 through 02.28.2020 using PubMed and applying the "PRISMA" guidelines. Inclusion and exclusion criteria were defined.

RESULTS

Our systematic review found 41 articles reporting an inverse (negative) relationship between prostate gland volume and incidence of prostate cancer. Sample sizes ranged from 114 to 6692 patients in these single institutional and multi-institutional studies. Thirty-nine (95%) of the 41 articles showed a statistically significant inverse relationship. In our search, no study was found showing a positive correlation between BPH size and the incidence of PCa.

CONCLUSION

To our knowledge, this is the first systematic review on the important clinical question of interaction between prostate size and the incidence of PCa. The results are demonstrating an inverse relationship, and therefore reveal strong evidence that large prostates may be protective of PCa when compared to smaller prostates.

Utility of the transition zone index for identification of prostate cancer in Chinese men with intermediate PSA levels

PURPOSE

We aimed to investigate the utility of the transition zone index (TZI) for identification of prostate cancer (PCa) in Chinese men with prostate-specific antigen (PSA) levels of 4-10 ng/mL.

METHODS

In this retrospective cohort study, results of transrectal ultrasonography (TRUS)-guided biopsy were assessed in 616 consecutive Chinese men; all subjects had intermediate serum PSA levels and normal digital rectal examination findings. The prostate and transition zone volumes were determined by TRUS. A TZI cutoff value of 0.47 produced the best sensitivity and specificity rates in receiver operating characteristic (ROC) curve analysis and thus was used to classify the study subjects into two subgroups: group 1 with TZI ≤ 0.47 and group 2 with TZI > 0.47. Logistic regression analysis was used to predict outcomes. The variables that were statistically significant in the stepwise logistic regression analysis were assessed using the ROC curve and the area under the curve.

RESULTS

Overall, 166 of the 616 patients (26.9%) had histologically confirmed PCa. A total of 238 (38.6%) patients were classified into group 1, of whom 97 (40.8%) exhibited a positive biopsy; and 378 (61.4%) patients were classified into group 2, of whom 69 (18.3%) exhibited a positive biopsy. The stepwise logistic regression analysis revealed that PSA density (PSAD) exhibited the strongest predictive value in the overall population and in group 1, whereas PSA transition zone density (PSATZD) was the optimal predictor in group 2. The ROC curve analysis revealed that when using the TZI-specific 100% sensitivity cutoffs, 17.7% and 25% of the biopsies were unnecessary and could be avoided in the overall patient population prior to and following the division into groups, respectively (P = 0.002). Using an individually generated 95% sensitivity cutoff of 0.12 ng/mL(2) for PSAD and a cutoff of 0.179 ng/mL(2) for PSATZD for TZI-stratified cohorts of TZI ≤ 0.47 and TZI > 0.47, a more consistent specificity of 44% and 46.9%, respectively, for each cohort was observed.

CONCLUSIONS

The optimal predictor for PCa differs between various TZI levels. The combination of PSAD in patients with TZI ≤ 0.47 and PSATZD in patients with TZI > 0.47 helps to identify potentially unnecessary biopsies compared to the use of a single PSAD for the entire patient population. The discrepancies regarding an optimal predictor in published reports are most likely due to the differing TZI levels among the cases. In this study, we demonstrated improved identification of PCa using TZI-adjusted cutoffs for PSAD and PSATZD.

Prostatic volume and volume-adjusted prostate-specific antigen as predictive parameters for prostate cancer patients with intermediate PSA levels

The object of the study was to examine the usefulness of volume-adjusted prostate-specific antigen (PSA) parameters for prediction of prostate cancer in the patients with intermediate PSA levels. The subjects were 235 patients with intermediate PSA levels (range: 4.1-10.0 ng/ml) whose prostate volume (PV) and prostate transition zone volume (TZV) were evaluated between August 1996 and April 2004. PSA, PV, TZV, PSA density (PSAD) (PSA/PV) and PSA transition zone density (PSATZD) (PSA/TZV) were assessed with the receiver operating characteristic (ROC) curve and the area under the curve (AUC). Simple and multivariate logistic regression analyses were used to analyze the odds ratios of age, PSA, PSAD, PSATZD, PV, TZV, digital rectal examination (DRE) and transrectal ultrasonography (TRUS) findings. Fifty-five patients (23.4%) of 235 patients had biopsy-proven prostate cancer. The univariate analysis revealed significant differences in the mean values of age, PSAD, PSATZD, PV, TZV and DRE between the patients with cancer and the non-cancer patients. The ROC curve analysis revealed that PV, TZV, PSAD and PSATZD had significant predictive values as compared with that of PSA. However, there was no difference in AUC between them. The stepwise logistic regression analysis showed that the age, PV, PSATZD and DRE had significant predictive values, and that PSATZD had the most predictive power. In conclusion, both PSAD and PSATZD had significant predictive values in discriminating prostate cancer. Furthermore, the stepwise logistic regression analysis showed that PSATZD had the strongest predictive value.

Total and free prostate-specific antigen indexes in prostate cancer screening: value and limitation for Japanese populations

AIM

To assess the efficacy and limitation of free/total prostate-specific antigen ratio (f/tPSA) at a single institution in Japan, focusing on the avoidance of pointless prostate biopsies.

METHODS

In total, 631 men between 44 and 93 years old (mean 69.8 years) with elevated PSA underwent power-Doppler ultrasoundgraphy-guided transrectal 10-core prostate biopsies at Niigata Cancer Center Hospital, and their histological features were investigated with total PSA (tPSA) and f/tPSA.

RESULTS

PCa was detected in 126 of 134 patients (94.3%) with tPSA of 26 ng/mL or higher. The detection rate was 59.4% for tPSA of 21-25 ng/mL, followed by 39.2% for 16-20 ng/mL, 30.0% for 11-15 ng/mL, 20.0% for 4.1-10 ng/mL and 7.6% for = or <4.0 ng/mL. f/tPSA of the PCa group was significantly lower than that of non-malignamt disorders in any tPSA ranges (mean 0.122 vs. 0.160, P<0.001). Receiver-operating characteristics analyses showed that f/tPSA (AUC:0.664) performed more valuably than tPSA (AUC:0.559) in patients with tPSA between 3.0-10 ng/mL (P<0.01). Although f/tPSA of 0.250 for the cut-off value might miss 1.8% PCa patients, it potentially spares 9.2% of unnecessary biopsies.

CONCLUSION

f/tPSA is more valuable compared with tPSA alone for the prediction of the occurrence of PCa. We recommend 0.250 as the cut-off value for f/tPSA in PCa screening for Asian men having so-called grey-zone tPSA.

Long-term outcomes of 60 Gy conventional radiotherapy combined with androgen deprivation for localized or locally advanced prostate cancer

BACKGROUND

Until 1998 in Japan, very few institutions were treating prostate cancer solely with radiotherapy (RT) >70 Gy and most were using < or =65 Gy in combination with hormone therapy. The present study reports the long-term results of RT combined with hormone therapy for localized and locally advanced prostate cancer.

METHODS

We investigated 57 patients who were treated by external beam RT plus hormone therapy (median age 79 years, median prostate-specific antigen concentration 15.0 ng/ml) between 1992 and 1998. Patients received 40 Gy of radiation to the pelvis and an additional 20 Gy as a prostatic boost. Hormone therapy was begun on the first day of irradiation and continued thereafter.

RESULTS

The median follow-up was 93.3 months and the 5 and 10 year actual overall survival rates were 67.8 and 32.6%, respectively, with 5 and 10 year cause-specific survival rates of 97.9 and 95.0%, respectively. The expected survival rate was 66.2% at 5 years, and overall survival was above expected survival. Only one patient developed severe proctitis (Grade 3). The 5 year occurrence of Grade 1/2 genitourinary toxicity was 23.2%.

CONCLUSIONS

Combined RT and hormone therapy has a good long-term outcome without severe adverse events. The overall survival rate compares well with the expected survival rate.

Using multiple cutpoints for the free-to-total prostate specific antigen ratio improves the accuracy of prostate cancer detection

BACKGROUND

Using a single cutpoint for the free-to-total (F/T) prostate specific antigen (PSA) ratio loses important diagnostic information. We evaluated the performance of multiple F/T PSA cutpoints in detecting prostate cancer in men with nonspecific PSA values.

METHODS

We extracted sensitivity and specificity data from 12 studies reporting on >or=30 cancer patients with PSA values between 2.0 and 10.0 ng/mL. We calculated stratum-specific likelihood ratios (LR) and areas under the receiver operating characteristic (ROC) curves.

RESULTS

Multiple cutpoints for the F/T PSA ratio significantly increased the area under the ROC (0.70) compared with the single investigator-selected cutpoint (0.62), P < 0.004. The LR for the most positive cutpoint stratum (2.62) was significantly higher than the LR for a positive test from the single cutpoint (1.36), P < 0.004.

CONCLUSIONS

Using multiple cutpoints increased the discriminating power of the F/T PSA ratio and led to greater probability revisions in the most positive test-result strata.

Likelihood of prostate cancer based on prostate-specific antigen density by MRI: retrospective analysis

OBJECTIVE

As a screening test for prostate cancer (PCA), prostate-specific antigen (PSA) may induce unnecessary prostate biopsy in patients with PSA 4.1-10.0 ng/ml. PCA detection may be delayed in patients with PSA < or =4.0 ng/ml. MRI-based PSA density of the prostate (PSAD) and of the prostatic transitional zone (PSAT) could improve differentiation of PCA and benign prostatic hyperplasia.

MATERIAL AND METHODS

Total prostate and transitional zone volumes were planimetrically determined in axial, T2-weighted fast spin echo MR images of the prostate. Serum PSA concentration was measured with an automated standardized microparticle enzyme immune assay. PSAD and PSAT were calculated in 17 patients with clinically significant PCA and 42 patients with benign prostatic hypertrophy (BPH) (66 +/- 6 versus 64 +/- 8 years, p = 0.2410, t test) who had PSA levels < or =10.0 ng/ml.

RESULTS

For differentiation of BPH and PCA, PSA alone above the optimal cutoff level of 4.2 ng/ml showed an odds ratio for PCA of 6.7 (95% confidence interval [CI], 1.9-23.2). PSAD showed an odds ratio for PCA of 71.3 (95% CI, 11.8-430.9) above the optimal cutoff level of 0.07 ng/ml/cc. PSAT demonstrated an odds ratio for PCA of 320.0 (95% CI, 27.1-3781.4) above the optimal cutoff level of 0.15 ng/ml/cc.

CONCLUSIONS

In patients with PSA < or =10.0 ng/ml, MRI-based PSAD and PSAT appear to improve differentiation of prostate cancer and BPH and are feasible to reduce the frequency of unnecessary prostate biopsy.

Performance evaluation of a new chemiluminescent assay for prostate specific antigen

Prostate specific antigen (PSA) is a glycoprotein found in the epithelial cells of the prostatic duct and acini. PSA is elevated in all four stages of prostate cancer as well as in benign prostatic hypertrophy. We evaluated a new chemiluminescent assay for PSA by comparing this assay with the microparticle enzyme immunoassay for PSA (MEIA) on the AxSYM analyzer (Abbott Laboratories, Abbott Park, IL) and a Hybritech Tandem R assay for PSA. The new chemiluminescent assay is recently available from Bayer Diagnostics (Tarrytown, NY) and can be run using the ACS: 180 Plus analyzer. Precision of the new chemiluminescent assay was evaluated using commercially available controls (Bayer Diagnostics). The within-run and total CVs were 6.4 and 8.7% for the low control (mean: 0.43 microg/L), 1.6 and 5.2% for the next level control (mean:1.94 mg/L), 4.3 and 4.9% for the medium control (mean: 2.10 mg/L), 1.2 and 3.9% for the high control 1 (mean: 11.52 mg/L), and finally 3.2 and 6.9% for the high control 2 (mean: 21.52 mg/L). The spike recovery varied from 94.2 to 109.6% for five different specimens we studied. We also observed excellent dilution recoveries. For example, in the specimen supplemented with 3.02 mg/L of PSA, the dilution recoveries were 102. 1, 104.7, and 103.7% for 1:2, 1:4, and 1:8 dilutions, respectively. We analyzed 113 serum specimens from patients with various concentrations of PSA (range 0.5 mg/L-2040 mg/L) using the new chemiluminescent assay and compared our results with the MEIA and Hybridtech (Tandem-R PSA) assays. Using x axis as the PSA concentrations obtained by the Tandem-R assay and the y axis as the PSA values obtained by the new chemiluminescent assay, we observed the following regression equations: y = 1.04 x -0.19 (r = 0.99, n = 112). One specimen with PSA concentrations of 2040 microg/L by the MEIA and 2156 microg/L by the chemiluminescent assay was not used for regression analysis. Similarly using x axis as the PSA concentrations obtained by the MEIA assay and y axis as the PSA concentrations obtained by the chemiluminescent assay, we observed the following regression equation: y = 0.88 + 0.02 (r = 0.99, n = 112). We conclude that the new chemiluminescent assay has excellent precision and the results compared well with the existing assays.