The effect of dutasteride on the peripheral and transition zones of the prostate and the value of the transition zone index in predicting treatment response

Computerized metric assessment of glandular tissue volume within the peripheral zone of the prostate using combined magnetic resonance imaging and histopathology: Possible pathophysiological implications on prostate cancer development

PURPOSE

Benign prostatic hyperplasia (BPH) and prostate cancer (PCa) are prevalent urological ailments in elderly males. Numerous clinical studies have revealed an invert association between BPH/prostate size and PCa growth. This study investigates the association between prostate size and total glandular tissue volume of the peripheral zone (GVPZ) using a unique blend of magnetic resonance imaging (MRI) and histo-anatomical imaging technique.

MATERIALS AND METHODS

Patients were selected who underwent both radical prostatectomy and preoperative MRI scans. MRI scans provided quantitative measurements of prostatic zone dimensions, while histo-anatomical slides yielded quantitative data on glandular density of the peripheral zone (PZ) using imaging software. Integration of MRI and histopathology enabled the assessment of the GVPZ. Statistical analysis identified relationships between total prostate volume (TPV) and GVPZ.

RESULTS

Seventy-two patients were selected and 40 cc was determined to be the optimal cutoff for small-to-moderate versus large prostates. Once the two subgroups in TPV were formed, the relationship between TPV and GVPZ was found to be highly significant (p<0.001).

CONCLUSIONS

The combination of MRI and histopathology offers a novel approach for precise quantification of glandular tissue within the prostatic PZ. This study corroborates the hypothesis of PZ compression via an enlarging transition zone in larger BPH prostates, resulting in PZ glandular atrophy. Given that most PCa originates in the PZ, these results shed light on the potential protective role of larger BPH prostates against PCa growth.

MRI determined prostate volume and the incidence of prostate cancer on MRI-fusion biopsy: a systemic review of reported data for the last 20 years

PURPOSE

Magnetic resonance imaging (MRI) is a precise, systemic and advantageous imaging technique when compared to transrectal ultrasound (TRUS) which is very operator dependent. The negative correlation between prostate volume and the incidence of prostate cancer (PCa) obtained by TRUS biopsy has been well documented in the literature. The purpose of this systemic review is analyzing the reported MRI-fusion study results on prostate biopsies regarding any correlation between prostate volume and the incidence of PCa.

METHODS

After defining the inclusion and exclusion criteria an in-depth review were performed between 01.01.2000 and 02.08.2022 using the PubMed database and applying the "PRISMA" guidelines.

RESULTS

Twelve studies qualified, and all showed an inverse/negative relationship between prostate volume and incidence of PCa. Sample sizes ranged from 33 to 2767 patients in single and multi-institutional studies. All studies showed a statistically significant inverse relationship with a p value < 0.05. The graph summarizing all of studies and using Fisher's method revealed a highly significant combined p level of 0.00001. Additionally, not one single study was found showing the contrary (a positive correlation between prostate size and the incidence of PCa).

CONCLUSION

To our knowledge, this is the first systemic review of reported MRI-Fusion data on the incidence of PCa in correlation with prostate volume. This MRI review confirms previous TRUS-biopsy studies which demonstrated an inverse relationship between prostate volume and the incidence of PCa, and thus further supports the hypothesis that large prostates size may be protective against PCa when compared to smaller prostates.

The P.R.OS.T.A.T.E Nomogram for the Preoperative Prediction of Clinical Efficacy of Transurethral Resection of the Prostate in Benign Prostatic Hyperplasia Patients

Purpose

Transurethral resection of the prostate (TURP) is often indicated for benign prostatic hyperplasia (BPH). Some patients, however, fail to adequately respond to these interventions. Accordingly, a powerful prediction model for TURP efficacy is warranted. This study aimed to create a nomogram with preoperative parameters for the prediction of individual TURP efficacy.

Methods

Clinical data from 356 BPH subjects who underwent TURP were retrospectively collected between November 2015 and June 2021 for nomogram development. The prediction model was developed using multivariable logistic regression analysis and presented as a nomogram. Nomogram performance was assessed through calibration curves and the concordance index (C-index). An independent validation cohort containing 177 consecutive patients in the corresponding period was used for external validation. The optimal cutoff value was determined through receiver operating characteristic curve (ROC) analysis by maximizing the Youden index, and its accuracy was assessed through sensitivity, specificity and predictive values.

Results

In multivariate analysis of the primary cohort, the independent factors for TURP efficacy were age, International Prostate Symptom Score (IPSS), intravesical prostatic protrusion (IPP), bladder wall thickness (BWT), peripheral zone thickness (PT) and transitional zone thickness (TT), all of which were included in the nomogram. The calibration curve for survival probability showed good agreement between the nomogram predictions and actual observations. The C-index for predicting TURP efficacy was 0.860 (95% confidence interval [CI], 0.808–0.911). The optimal cutoff total nomogram score was 177, with a maximum Youden index of 0.643. The sensitivity, specificity, positive predictive value, and negative predictive value for predicting TURP efficacy were 70.6%, 75.6%, 90.6%, and 43.7% in the validation cohort, respectively. Logistic regression analysis in the validation cohort demonstrated that the area under the curve (AUC) was 0.806 (95% CI, 0.733–0.879).

Conclusion

The P.R.OS.T.A.T.E nomogram objectively and accurately predicted TURP efficacy, thereby facilitating the clinical decision-making process.

The cutoff value of transitional zone index predicting the efficacy of dutasteride on subjective symptoms in patients with benign prostate hyperplasia

OBJECTIVES

We investigated the efficacy of dutasteride add-on therapy to α-1 adrenoceptor antagonists in patients with benign prostate hyperplasia (BPH) in relation to the transitional zone index (TZI) and evaluated the cutoff value of TZI that predicted improvements of subjective symptoms at 6 months.

METHODS

Male BPH patients with prostate volume (PV) ≥ 30 mL receiving dutasteride 0.5 mg/d for 6 months as add-on therapy along with α-1 adrenoceptor antagonists were enrolled. PV, transitional zone volume (TZV), TZI, International Prostate Symptom Score (IPSS), and uroflowmetry parameters before and at 6 months with dutasteride add-on treatment were evaluated.

RESULTS

Eighty-three patients were included. The changes of total IPSS, IPSS voiding subscore, IPSS quality of life score, and voided volume were significantly correlated with TZI. Among baseline parameters, TZV and TZI were significantly associated with the changes of total IPSS in univariate analysis, and only TZI remained as an independent predictive factor for improving total IPSS in multivariate analysis (odds ratio -8.3, P = .048). The cutoff point of TZI for predicting an improvement of the total IPSS by 6 points or more was 0.67 (area under the curve 0.71, sensitivity 0.62, specificity 0.79).

CONCLUSIONS

A higher TZI was significantly associated with improvement of subjective symptoms but not uroflowmetric findings for BPH patients with 6 months of dutasteride add-on therapy along with α-1 adrenoceptor antagonists, and the predictive value of TZI for effective dutasteride add-on therapy was higher than 0.67. BPH patients using α-1 adrenoceptor antagonists with a TZI higher than 0.67 can be good candidates for add-on dutasteride therapy.

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.

Prostatic anatomical parameters correlate with clinical characteristics suggestive of benign prostatic hyperplasia

We conducted the present study to assess the correlation of the prostatic anatomical parameters, especially the ratio of peripheral zone thickness and transitional zone thickness, with clinical and uroflowmetry characteristics suggestive of benign prostate hyperplasia (BPH). A total of 468 consecutive patients with a detailed medical history were identified. All patients were evaluated by scoring subjective symptoms with the International Prostate Symptom Score (IPSS) and quality of life (QoL). The prostatic anatomical parameters were measured using transrectal ultrasonography, and postvoid residual urine and maximum flow rate (Q_max) values were also determined. Pearson's correlation analysis revealed that both total prostate volume (TPV; r = 0.160, P < 0.001) and transitional zone volume (TZV; r = 0.104, P = 0.016) increased with patients' age; however, no correlations were observed of TPV, TZV, transitional zone index (TZI), and transitional zone thickness (TZT) with IPSS or QoL (all P > 0.05). Peripheral to transitional zone index (PTI) was found negatively correlated with total IPSS (r = −0.113, P = 0.024), storage IPSS (r = −0.103, P = 0.041), and voiding IPSS (r = −0.123, P = 0.014). As regards the uroflowmetry characteristics, PTI (r = 0.157, P = 0.007) was indicated to be positively correlated with Q_max and negatively correlated with TZI (r = −0.119, P = 0.042) and TZT (r = −0.118, P = 0.045), but not correlated with TPV, TZV, or peripheral zone thickness (PZT) (all P > 0.05). Postvoid residual urine (PVR) had not correlated with all the prostatic anatomical variables (all P > 0.05). This is the first study that formally proposed the concept of PTI, which is an easy-to-measure prostate anatomical parameter which significantly correlates with total IPSS, storage IPSS, voiding IPSS, and Q_max, suggesting that PTI would be useful in evaluating and managing men with lower urinary tract symptoms (LUTS)/BPH. However, well-designed studies are mandatory to verify the clinical utility of PTI.

Prostatic peripheral zone thickness: what is normal on magnetic resonance imaging?

PURPOSE

To report the precision of a technique of measuring the PZ thickness on T2-weighted MRI and report normal parameters in patients with normal-sized prostates. We also wanted to establish the mean and second standard deviations (2SD) above and below the mean as criteria for abnormally narrow or expanded PZ thickness.

METHODS

Of the initial 1566 consecutive cohort referred for evaluation for carcinoma based on elevated PSA (prostate specific antibody) or DRE (digital rectal examination), 132 separate subjects with normal-sized prostates were selected for this study. Mean age was 58.2 years (15-82). Median serum PSA was 6.2 ng/mL (range 0.3-145). Most were asymptomatic for lower urinary tract symptoms (LUTS). Inclusion criteria in this study required technically adequate T2-weighted MRI and total prostatic volume (TPV) ≤ 25 cc. Exclusion criteria included post-prostatic surgical and radiation patients, patients having had medical management or minimally invasive therapy for BPH, those being treated for prostatitis. Patients with suspected tumor expanding or obscuring measurement boundaries were also not considered. Transition zone (TZ) and peripheral zone (PZ) volumes were determined using the prolate ellipsoid model. Posterolateral measurement of the PZ was obtained at the axial level of maximal transverse diameter of the prostate on a line drawn from the outer boundary of the TZ to the inner boundary of the external prostatic capsule (EPC). The data were normally distributed. Therefore, it was analyzed using the 2-sided student t-test and Pearson product correlation statistic.

RESULTS

Mean pooled (composite) measurement for the posterolateral PZ (PLPZ) was 10 mm (CI 9.5-10.5 mm) with SD of 2.87 mm. Means were statistically the same for the 2 observers (p = 0.75). Pearson correlation between the two observers was 0.63.

CONCLUSIONS

In a prostate ≤ 25 cc volume , the posterolateral PZ should be no thicker than 15.8 mm and averages 10.0 mm when measured in the maximal axial plane on MRI. These norms were independent of age or use of endorectal coil. The technique measurement demonstrated clinically useful precision.

PI-RADS score v.2 in predicting malignancy in patients undergoing 5α-reductase inhibitor therapy

BACKGROUND

To investigate if the PI-RADS score represents an effective tool in detecting prostate cancer in patients treated with a 5α-reductase inhibitor (dutasteride) and to identify dedicated total serum PSA and PSA density thresholds.

METHODS

Between April 2015 and March 2018, 75 patients under dutasteride treatment underwent multi-parametric magnetic resonance imaging (mpMRI) scans and US/MRI fusion prostate biopsy. Lesions were classified into two groups: Group 1 included PI-RADS 4 and 5 lesions, whilst Group 2 included PI-RADS 3-4-5 lesions. Lesions in groups 1 and 2 were further divided according to the patients' history of previous prostate biopsy.

RESULTS

Ninety-seven lesions were detected. In PI-RADS 4-5 group, mpMRI showed a sensitivity of 78.0% and a specificity of 78.7%. The positive predictive value (PPV) was 79.6% and the negative predictive value (NPV) 77.1%. In PI-RADS 3-4-5 group, sensitivity was 100%, specificity 21.3%, PPV 57.5%, NPV 100%. In PI-RADS 4-5 biopsy-naive group sensitivity was 71.4%, specificity 75.0%. PPV 78.9% and NPV 66.7%. In PI-RADS 4-5 non-biopsy-naive group sensitivity was 82.8%, specificity 80.6%, PPV 80%, and NPV 83.3%. PI-RADS 3-4-5 biopsy-naive group showed sensitivity 100%, specificity 31.3%, PPV 65.6%, NPV 100%. PI-RADS 3-4-5 non-biopsy-naive group showed sensitivity 100%, specificity 16.1%, PPV 52.7%, and NPV 100%. ROC curve analysis indicated a serum total PSA threshold of 6 ng/ml (AUC: 0.71-95% confidence interval: 0.60-0.81) and a PSA density >0.22 (AUC: 0.70-95% confidence interval: 0.6-0.81) as optimal cut-offs for recommending prostate biopsy.

CONCLUSIONS

In our experience the PI-RADS score proved to be sufficiently accurate in predicting prostate cancer in patients under dutasteride therapy.

Effectiveness and safety of electroacupuncture and its cotreatment with electronic moxibustion in the treatment of patients with moderate benign prostatic hyperplasia using alpha blocker: Study protocol for an assessor-blinded, randomized controlled clinical trial

BACKGROUND

Benign prostatic hyperplasia (BPH) is a medical condition that affects the quality of life by causing lower urinary tract symptoms (LUTS) in 40% to 70% of men aged ≥60 years. Medication treatment is primarily recommended for patients with BPH if their symptom score based on the International Prostate Symptom score (IPSS) is above the moderate level. However, electroacupuncture (EA) and electronic moxibustion (EM), one of the most recent complementary and alternative treatments, are suggested as adjuvant treatments in the improvement of LUTS caused by BPH with respect to the limitations of medication treatments, such as side effects or no improvement in LUTS despite treatment. Therefore, this study aimed to evaluate the effectiveness and safety of EA and its cotreatment with EM for the improvement of LUTS in patients diagnosed with BPH using an alpha blocker but with moderate symptoms on the basis of IPSS.

METHODS/DESIGN

This protocol is a 2-arm parallel-design, randomized, controlled assessor-blinded clinical trial. Seventy-eight patients diagnosed with BPH are randomized to one of the following groups: [EA and its cotreatment with EM + alpha blocker group] and [alpha blocker group]. [EA and its cotreatment with EM + alpha blocker group] continues to use the previously prescribed alpha blocker and visits the study institution 3 times a week for 6 weeks to receive the cotreatment of EA and EM. [Alpha blocker group] continues to use the previously prescribed alpha blocker for 6 weeks. To evaluate the effectiveness of the EA and its cotreatment with EM, the followings are measured: total score of the IPSS, IPSS quality of life assessment, EuroQol-Five dimension, maximum and average urinary flow rate (Qmax and Qave), and prostate size at the baseline, 3rd, 6th, and 12th weeks. The primary effectiveness endpoint measures the average change in the total score of the IPSS at the 6th week. Side effects are recorded at each visit.

DISCUSSION

The results of this study are expected to provide useful information on the effectiveness and safety of the EA and its cotreatment with EM for patients with BPH with regard to the improvements in LUTS.

TRIAL REGISTRATION

Clinical Research Information Service of Republic of Korea (CRIS-KCT0004411), October 31, 2019.

Is prostate volume better than PSA density and free/total PSA ratio in predicting prostate cancer in patients with PSA 2.5-10 ng/mL and 10.1-30 ng/mL?

Objective: Benign prostatic hyperplasia (BPH) and prostate cancer (PCa) are the most common benign and malignant diseases of the prostate gland. The clinical distinction between BPH and PCa should be determined to guide patients to appropriate treatment. We aimed to evaluate the value of PSA, prostate volume (PV) and associated parameters for the detection of PCa in patients with PSA levels of 2.5-30.0 ng/mL.Materials and methods: A total of 211 men with a biopsy (≥10 cores) and a PSA of 2.5-30.0 ng/ml were included in the study. To evaluate the performance of PV in diagnosing PCa, subjects were divided into PSA 2.5-10.0 ng/ml and PSA 10.1-30.0 ng/ml groups. Age, BMI, PSA, PV, f/t PSA, PSAD, and biopsy Gleason score were included in the analysis.Results: PCa was diagnosed in 74 (35.1%) of the 211 patients. The differences in f/t PSA, PV, and PSAD for patients with and without PCa were statistically significant. (p < .001). PV was a significantly better indicator of PCa than PSAD and f/t PSA ratio in both groups.Conclusions: PV plays an active role in predicting PCa in patients with PSA in gray-zone as well as in patients with PSA 10.1-30 ng/mL.

Prostate Benign Diseases

Magnetic resonance imaging (MRI) has been increasingly used in the detection, localization, and staging of prostate cancer. Because of its excellent soft tissue contrast and multiplane imaging, it can be also very useful in the evaluation of benign prostate diseases. Prostatic benign disorders have a high prevalence, vastly represented by benign prostatic hyperplasia and prostatitis. On the contrary, benign prostatic neoplasms are extremely rare, represented by multilocular cystadenoma, leiomyomas, hemangioma, and granular cell tumor, although these uncommon tumors have been most encountered due to widespread use of MRI. Congenital prostatic anomalies are associated with defects in the development of the prostate embryology, including hypoplasia, ectopia, and vascular malformations, abnormalities rarely seen on cross-sectional imaging. Prostatic cysts are the most common development abnormalities and occasionally are related to clinical symptoms, mainly due to infection and hemorrhage. As with prostate cancer, multiparametric MRI is a reliable tool for the diagnosis and management of benign prostatic diseases as well, providing additional information such morphological changes of the prostate, more accurate prostatic measurements, and functional characteristics of nonmalignant prostatic lesions. In this review, we discuss MRI findings of these benign prostatic diseases.

Modified simple prostatectomy: an approach to address large volume BPH and associated prostate cancers

Simple prostatectomy is an option for management of patients with enlarged prostates and obstructive symptoms. However, the guidelines still do not state a gold-standard treatment for men with BPH and some of these patients with BPH are also known to harbor prostate cancer. This issue can be a challenge because, in the traditional simple prostatectomy, the prostate capsule is often left in place, and that is usually the area of the prostate cancers. With the robotic approach, our goal is to analyze the outcomes of modified simple prostatectomy (MSP) by the elimination of the entire prostate tissue. Thirty-four patients underwent MSP for BPH diagnosis. We evaluated the pre- and postoperative clinical characteristics as well as pathological data. MSP was performed using the DaVinci Xi robot; the entire prostate was removed. We performed a full nerve sparing bilaterally with an intrafascial plane dissection, minimal apical dissection, seminal vesicles sparing, and full vesicourethral anastomosis. The pre- and postoperative AUA scores were compared on paired T test. The mean operative time and blood loss were 126 min and 160.5 ml, respectively. The final pathology report described 17 patients (50%) with BPH and 17 (50%) with BPH and prostate adenocarcinoma. After surgery, 97% had an AUA score improvement. Regarding the patients with a prostate cancer diagnosis, 97% had PSA lower than 0.01 ng/ml. Modified simple prostatectomy is an acceptable treatment option for men with BPH. The procedure allows for significant symptom relief and removal of chronic catheters. Our modified approach was able to eliminate the entire prostate, which was significant because 50% of these patients had prostate cancer on the final pathology.

The effect of 5 alpha-reductase inhibitor therapy on prostate cancer detection in the era of multi-parametric magnetic resonance imaging

We aimed to evaluate the effect of 5 alpha-reductase inhibitor (5-ARI) treatment on prostate cancer (PCa) and clinically significant PCa (csPCa) detection in patients undergoing transrectal ultrasound (TRUS)/magnetic resonance imaging (MRI) fusion biopsy in the current era of multi-parametric MRI (mpMRI). We retrospectively reviewed our TRUS/MRI fusion biopsy database (n = 706). Eighty (11.3%) patients who had used 5-ARI for more than one year at the time of biopsy were stratified as 5-ARI group. Subsequently, we performed comparative analyses of 5-ARI and non-5-ARI groups. csPCa was defined by a Gleason score ≥3 + 4 in a single biopsy core. Chi-squared test was used to evaluate the performance of mpMRI in predicting PCa/csPCa between the two groups. Multivariate logistic regression analyses were performed to evaluate the significant variables associated with PCa detection. There were no significant differences in PCa/csPCa detection rates between 5-ARI and non-5-ARI groups (all, P > 0.05). In multivariate logistic regression analyses for the evaluation of variables associated with csPCa detection, age (odds ratio [OR], 1.062; 95% confidence interval [CI], 1.035–1.090; P < 0.001), pre-biopsy PSA (OR, 1.062; 95% CI, 1.034–1.090; P < 0.001), prostate volume on TRUS (OR, 0.956; 95% CI, 0.943–0.970, P < 0.001), and PI-RADsV2 category (OR, 5.528; 95% CI, 3.017–10.131; P < 0.001) were found to be significant predictors. However, 5-ARI had no significant association with PCa detection (P = 0.384). Conclusively, 5-ARI therapy did not adversely affect PCa/csPCa detection after TRUS/MRI fusion biopsy, which suggests that exposure to 5-ARI may not impair the performance of mpMRI.

Histological changes of the peripheral zone in small and large prostates and possible clinical implications

Introduction

It is well documented in literature that most prostate carcinomas (PCa) arise in the peripheral zone (PZ). Additionally, an inverse relationship between prostate size and the incidence of PCa has been demonstrated in recent studies. However, little is known about gland distribution in the peripheral zone of larger prostates compared to smaller prostates. In this study, we examined the histo-anatomical gland distribution within the peripheral zone in small and large prostates and discuss possible clinical implications.

Methods

A semi-quantitative analysis of gland density and capsule thickness was performed using light microscopy on 10 large (≥80 g) prostate specimens and 10 small (<30 g) prostate specimens from patients who underwent radical prostatectomy at Texas Tech University Health Sciences Center between the years 2010 and 2016. Samples from radical prostatectomies were used to ensure a whole, preserved prostate with an intact surgical capsule. Gland counts were performed on five random fields under 100 × magnification, while capsule thickness was measured on three random fields per case; thus, a total 50 fields and 30 fields were analyzed for each of the two groups for gland counts and capsule thickness measurements, respectively. Microscopy was standardized to the posterior aspect of the prostate, between 4 o'clock and 6 o'clock along the equatorial region between the apex and base.

Results

Large prostates possessed a significantly lower mean gland count per field compared to small prostates (10.34±4.15, n=50 vs 18.00±5.41, n=50; t=8.16, df=49, P<0.001). Additionally, large prostates showed a significantly higher average capsule thickness in millimeters compared to small prostates (1.80 mm, ±1.12 mm, n=30 vs 0.90 mm, ±0.56, n=30; t=8.16, df=49, P<0.001).

Conclusion

The results demonstrate that prostate hypertrophy leads to both decreased gland density in the peripheral zone and increased capsule thickness, suggesting that growth-induced expansion of the prostate against its capsule leads to compression-induced atrophy and fibrosis of glandular tissue within the peripheral zone (PZ). A decrease in gland density within the PZ may have clinical implications shedding light, for instance, on the reduction in PCa incidence in patients with large prostates as compared to smaller prostates, a phenomenon well documented in the literature.

MRI findings in men on active surveillance for prostate cancer: does dutasteride make MRI visible lesions less conspicuous? Results from a placebo-controlled, randomised clinical trial

OBJECTIVES

To investigate changes in the Apparent Diffusion Coefficient (ADC) using diffusion-weighted imaging (DWI) in men on active surveillance for prostate cancer taking dutasteride 0.5 mg or placebo.

METHODS

We analysed 37 men, randomised to 6 months of daily dutasteride (n = 18) or placebo (n = 19), undergoing 3T multi-parametric Magnetic Resonance Imaging (mpMRI) scans at baseline and 6 months. Images were reviewed blind to treatment allocation and clinical information. Mean ADC of peripheral (PZ) and transition (TZ) zones, and MR-suspicious lesions were compared between groups over 6 months. Conspicuity was defined as the PZ divided by tumour ADC, and its change over 6 months was assessed.

RESULTS

A decrease in mean conspicuity in the dutasteride group (but not the controls) was seen over 6 months (1.54 vs 1.38; p = 0.025). Absolute changes in ADC and conspicuity were significantly different between placebo and dutasteride groups at 6 months: (-0.03 vs 0.08, p = 0.033) and (0.11 vs -0.16, p = 0.012), as were percentage changes in the same parameters: (-2.27% vs 8.56% p = 0.048) and (9.25% vs -9.89% p = 0.013).

CONCLUSIONS

Dutasteride was associated with increased tumour ADC and reduced conspicuity. A lower threshold for triggering biopsy might be considered in men on dutasteride undergoing mpMRI for prostate cancer.

KEY POINTS

• Dutasteride increases ADC and reduces conspicuity in small mpMRI-visible prostate cancers. • Knowledge of dutasteride exposure is important in the interpretation of prostate mpMRI. • A lower threshold for triggering biopsy may be appropriate on dutasteride.

Association of prostate volume with incidence and aggressiveness of prostate cancer

Objective

The aim of this study was to investigate the possible correlation between prostate volume and aggressiveness and incidence of prostate cancer (PCa).

Patients and methods

A chart review of a cohort of 448 consecutive prostate biopsy-naive men was performed. These men underwent at least a 12-core biopsy at our institution due to increased prostate-specific antigen serum levels (>4 ng/mL) and/or suspicious findings on digital rectal examination during the period between 2008 and 2013. Transrectal ultrasound was used to determine the prostate volume.

Results

The positive biopsy rate was 66% for patients with a prostate volume of ≤35 cc and 40% for patients with a prostate volume of ≥65 cc (P<0.001). Of the 110 patients testing positive on biopsy with a volume of ≤35 cc, 10 patients (9.1%) had a Gleason score of ≥8. Of the 27 patients testing positive on biopsy with a volume of ≥65 cc, only 1 patient (3.7%) had a Gleason score of ≥8.

Conclusion

These results suggest that there may be an association between prostate volume and the incidence and aggressiveness of PCa. The larger the prostate, the lower the positive biopsy rate for PCa and the lower the Gleason score.

Combination of intravesical prostatic protrusion and resistive index is useful to predict bladder outlet obstruction in patients with lower urinary tract symptoms suggestive of benign prostatic hyperplasia

OBJECTIVES

To examine which parameters obtained from transrectal ultrasonography are accurate predictors of urodynamically-confirmed bladder outlet obstruction in patients with lower urinary tract symptoms suggestive of benign prostatic hyperplasia.

METHODS

The records of 350 patients with complaints of lower urinary tract symptoms suggestive of benign prostatic hyperplasia were reviewed. Baseline parameters were international prostate symptom score, quality of life score, postvoid residual urine volume, prostate-specific antigen, and data obtained from uroflowmetry and transrectal ultrasonography. Urodynamic studies were carried out to determine bladder outlet obstruction. Receiver operator characteristic curves were generated to compare the accuracy of the different parameters, and the area under the curve of each parameter was calculated.

RESULTS

Bladder outlet obstruction index positively correlated with intravesical prostatic protrusion, total prostate volume, transition zone volume, transition zone index, resistive index and prostate-specific antigen. Further, resistive index was only a significant independent variable with intravesical prostatic protrusion. Intravesical prostatic protrusion had the highest area under the curve of 0.790 among all variables, and its cut-off value was 10 mm. The positive predictive value of intravesical prostatic protrusion was 76.2%. In addition, the positive predictive value of the combined parameters intravesical prostatic protrusion and resistive index increased to 83.8%.

CONCLUSIONS

Intravesical prostatic protrusion and resistive index are useful parameters for predicting bladder outlet obstruction in patients with lower urinary tract symptoms suggestive of benign prostatic hyperplasia. In clinical practice, the combination of intravesical prostatic protrusion and resistive index on ultrasound can be diagnostic of bladder outlet obstruction.

Korean clinical practice guideline for benign prostatic hyperplasia

In 2014, the Korean Urological Association organized the Benign Prostatic Hyperplasia Guideline Developing Committee composed of experts in the field of benign prostatic hyperplasia (BPH) with the participation of the Korean Academy of Family Medicine and the Korean Continence Society to develop a Korean clinical practice guideline for BPH. The purpose of this clinical practice guideline is to provide current and comprehensive recommendations for the evaluation and treatment of BPH. The committee developed the guideline mainly by adapting existing guidelines and partially by using the de novo method. A comprehensive literature review was carried out primarily from 2009 to 2013 by using medical search engines including data from Korea. Based on the published evidence, recommendations were synthesized, and the level of evidence of the recommendations was determined by using methods adapted from the 2011 Oxford Centre for Evidence-Based Medicine. Meta-analysis was done for one key question and four recommendations. A draft guideline was reviewed by expert peer reviewers and discussed at an expert consensus meeting until final agreement was achieved. This evidence-based guideline for BPH provides recommendations to primary practitioners and urologists for the diagnosis and treatment of BPH in men older than 40 years.

Clinical value of prostate segmentation and volume determination on MRI in benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a nonmalignant pathological enlargement of the prostate, which occurs primarily in the transitional zone. BPH is highly prevalent and is a major cause of lower urinary tract symptoms in aging males, although there is no direct relationship between prostate volume and symptom severity. The progression of BPH can be quantified by measuring the volumes of the whole prostate and its zones, based on image segmentation on magnetic resonance imaging. Prostate volume determination via segmentation is a useful measure for patients undergoing therapy for BPH. However, prostate segmentation is not widely used due to the excessive time required for even experts to manually map the margins of the prostate. Here, we review and compare new methods of prostate volume segmentation using both manual and automated methods, including the ellipsoid formula, manual planimetry, and semiautomated and fully automated segmentation approaches. We highlight the utility of prostate segmentation in the clinical context of assessing BPH.

Clinical significance of peripheral zone thickness in men with lower urinary tract symptoms/benign prostatic hyperplasia

OBJECTIVE

To evaluate the clinical impact of prostate peripheral zone thickness (PZT), based on presumed circle area ratio (PCAR) theory, on urinary symptoms in men with lower urinary tract symptoms/benign prostatic hyperplasia (LUTS/BPH) as a novel prostate parameter.

PATIENTS AND METHODS

Medical records were obtained from a prospective database of first-visit men with LUTS/BPH. Age, international prostate symptom score (IPSS), overactive bladder symptom score (OABSS), maximum urinary flow rate (Qmax ), and post-void residual urine volume (PVR) were assessed. Total prostate volume (TPV), transition zone volume (TZV), transition zone index (TZI), and PZT were measured by transrectal ultrasonography. Reliability analysis was also performed.

RESULTS

In all, 1009 patients were enrolled for the analysis. The mean (sd) PZT was 11.10 (2.50) mm, and patients were classified into three groups PZT thickness groups; PZT <9.5 mm, ≥9.5 to <13 mm, and ≥13 mm. As the PZT became smaller, all urinary symptom scores including IPSS, quality of life (QoL), and OABSS significantly increased. Uroflowmetry variables, such as Qmax and PVR, also showed significant differences. PZT showed a high intra-class correlation coefficient (0.896). Multivariate analysis revealed that the PZT was independently associated with IPSS (P < 0.001), QoL (P = 0.003), OABSS (P = 0.001), and PVR (P = 0.001), but PZT influence on Qmax was only of borderline significance (P = 0.055).

CONCLUSION

PZT is a novel, easy-to-measure prostate parameter that is significantly associated with urinary symptoms. Our present findings suggest that clinical usefulness of PZT should be further validated for managing men with LUTS/BPH.

An introduction to acinar pressures in BPH and prostate cancer

Intra-acinar and peri-acinar pressures in the prostate might be key factors in the evolution of its zonal morphology and the pathogenesis of BPH and cancer. Herein, I hypothesize that intra-acinar pressures lead to a decrease in apoptosis by distending or stretching acinar epithelium and its surrounding stroma. Increased prostatic smooth muscle content and tone might generate peri-acinar pressures, which could, in the long-term, counteract intra-acinar pressures and decrease epithelial stretch. Thus, it is proposed that BPH (characterized by increased prostatic smooth muscle and, therefore, raised peri-acinar pressures) might decrease the risk of prostate cancer progression by counteracting intra-acinar pressures. In the context of this theory, the transition zone might have evolved as a specialized region within the prostate that can mount a concerted stromal-epithelial response to increased urethral and intra-acinar pressures (BPH), and the urethral angulation, anterior stroma and the prostatic capsule have an adjunctive evolutionary role in this phenomenon.

MAPPED study design: a 6 month randomised controlled study to evaluate the effect of dutasteride on prostate cancer volume using magnetic resonance imaging

OBJECTIVE

To evaluate the percentage change in volume of prostate cancer, as assessed by T2-weighted MRI, following exposure to dutasteride (Avodart) 0.5mg daily for six months.

PATIENTS AND METHODS

MRI in Primary Prostate cancer after Exposure to Dutasteride (MAPPED) is a double-blind, placebo-controlled trial, supported by GlaxoSmithKline (GSK). Men with prostate cancer suitable for active surveillance (low-intermediate risk prostate cancer on biopsy), and a visible lesion on T2-weighted MRI of at least 0.2 cc, were eligible for consideration. Forty-two men were randomised to 6 months of daily dutasteride 0.5mg or placebo. Multi-parametric MRI (mpMRI) scans were performed at baseline, 3 and 6 months. The percentage changes in cancer volume over time will be compared between the dutasteride and placebo groups. Planned analyses will examine the association between tumour volume and characteristics (perfusion and contrast washout) as seen on mpMRI, HistoScan ultrasound and biopsy histopathology in both groups.

DISCUSSION

MAPPED is the first randomised controlled trial to use mpMRI to look at the effect of dutasteride on the volume of prostate cancer. If dutasteride is shown to reduce the volume of prostate cancer, it might be considered as an adjunct for men on active surveillance. Analysis of the placebo arm will allow us to comment on the short-term natural variability of the MR appearance in men who are not receiving any treatment.

CONCLUSION

MAPPED will evaluate the short-term effect of dutasteride on prostate cancer volume, as assessed by mpMRI, in men undergoing active surveillance for low or intermediate risk prostate cancer. The study completed recruitment in January 2012.

The REDUCE trial: chemoprevention in prostate cancer using a dual 5alpha-reductase inhibitor, dutasteride

Dutasteride, a dual 5alpha-reductase inhibitor, is used in the treatment of benign prostatic hyperplasia (BPH). It reduces serum prostate-specific antigen levels by approximately 50% at 6 months and total prostate volume by 25% after 2 years. Randomized placebo-controlled trials in BPH patients have shown the efficacy of dutasteride in symptomatic relief, improvements in quality of life and peak urinary flow rate. Side effects occurring with dutasteride are decreased libido, erectile dysfunction, ejaculation disorders and gynecomastia. Preliminary data from placebo-controlled BPH trials have shown a decrease in the detection of prostate cancer in patients treated with dutasteride, although these studies were not designed to look at this issue. Dutasteride differs from finasteride in that it inhibits both isoenzymes of 5alpha-reductase, type I and type II. The landmark Prostate Cancer Prevention Trial at the end of the 7-year study demonstrated a 24.8% reduction in the incidence of prostate cancer in the finasteride group compared with placebo. However, a 25.5% increase in the prevalence of high-grade Gleason tumors has been observed, the clinical significance of which has been debated. Preliminary data suggest a decrease in prostate cancer incidence in dutasteride-treated patients and demonstrate type I alphareductase enzyme expression in prostate cancer. As a result, dutasteride is being investigated for prostate cancer prevention in the ongoing Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial, which is discussed here.

5alpha-reductase inhibitors in benign prostatic hyperplasia and prostate cancer risk reduction

Androgens play an essential role in prostatic development and function, but are also involved in prostate disease pathogenesis. The primary prostatic androgen, dihydrotestosterone (DHT), is synthesized from testosterone by 5alpha-reductase types 1 and 2. Inhibition of the 5alpha-reductase isoenzymes therefore has potential therapeutic benefit in prostate disease. The two currently approved 5alpha-reductase inhibitors (5ARIs), finasteride and dutasteride, have demonstrated long-term efficacy and safety in the treatment of benign prostatic hyperplasia. Finasteride, a type-2 5ARI, has also been studied for its ability to reduce the incidence of biopsy-detectable prostate cancer in the Prostate Cancer Prevention Trial. Treatment with dutasteride, a dual 5ARI, has been shown to result in a greater degree and consistency of DHT suppression compared with finasteride. Two large-scale studies of dutasteride are currently investigating the role of near-maximal DHT suppression in the settings of prostate cancer risk reduction and expectant management of localized prostate cancer.