Long-term effects of finasteride on prostate tissue composition

Network pharmacology and experimental validation to explore the pharmacological mechanism of saw palmetto and its core ingredients in benign prostatic hyperplasia treatment

Benign prostatic hyperplasia (BPH) is a prevalent urological condition that predominantly affects the geriatric male population, resulting in lower urinary tract symptoms. Saw palmetto is a traditional Chinese medicine for treating BPH. This study aimed to investigate the potential therapeutic mechanisms of saw palmetto in BPH treatment. The active ingredients and potential targets of saw palmetto were obtained through the TCMSP database. BPH-related targets were retrieved from the GeneCards database. PPI, GO, and KEEG analyses were performed to predict the potential therapeutic mechanism. The active ingredient-common target and common target-pathway networks were constructed by Cytoscape software. Molecular docking and cellular experiments were carried out to further validate the potential mechanism. We obtained 13 active components in saw palmetto and 56 common targets in BPH treatment. KEEG analysis showed that the estrogen signaling pathway was the most enriched and exhibited a close association with BPH. PPI analysis, along with ingredient-target and target-pathway network analyses, indicated that stigmasterol was the core ingredient and PGR, NCOA1, and NCOA2 were identified as the hub genes mediating the effects of saw palmetto against BPH. In addition, molecular docking showed that stigmasterol had strong binding to PGR, NCOA1, and NCOA2. Cellular experiments revealed that stigmasterol significantly increased the percentage of BPH-1 cells in the G0/G1 phase and inhibited cell viability and division. Furthermore, it notably reduced the expression of PGR, NCOA1, and NCOA2. Saw palmetto might inhibit cell viability and division by suppressing the expression of PGR, NCOA1, and NCOA2, thereby playing a therapeutic role in treating BPH.

Spatial transcriptomics identifies candidate stromal drivers of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is the nodular proliferation of the prostate transition zone in older men, leading to urinary storage and voiding problems that can be recalcitrant to therapy. Decades ago, John McNeal proposed that BPH originates with the "reawakening" of embryonic inductive activity by adult prostate stroma, which spurs new ductal proliferation and branching morphogenesis. Here, by laser microdissection and transcriptional profiling of the BPH stroma adjacent to hyperplastic branching ducts, we identified secreted factors likely mediating stromal induction of prostate glandular epithelium and coinciding processes. The top stromal factors were insulin-like growth factor 1 (IGF1) and CXC chemokine ligand 13 (CXCL13), which we verified by RNA in situ hybridization to be coexpressed in BPH fibroblasts, along with their cognate receptors (IGF1R and CXCR5) on adjacent epithelium. In contrast, IGF1 but not CXCL13 was expressed in human embryonic prostate stroma. Finally, we demonstrated that IGF1 is necessary for the generation of BPH-1 cell spheroids and patient-derived BPH cell organoids in 3D culture. Our findings partially support historic speculations on the etiology of BPH and provide what we believe to be new molecular targets for rational therapies directed against the underlying processes driving BPH.

Holmium Laser Enucleation of the Prostate Efficiency by Prostate Gland Size: Is There a Sweet Spot?

Holmium laser enucleation of the prostate (HoLEP) is one of only two AUA guideline-recommended prostate size-independent surgeries for benign prostate hyperplasia (BPH). The significant variation in gland size treated results in a wide range of enucleation and morcellation times. We sought to understand the effect of prostate size on HoLEP efficiency to better educate patients and improve operative room utilization. After IRB approval, we identified patients from 1 July 2016 to 1 January 2020 who underwent HoLEP by two endourologists. Our primary objectives were to assess the effects of increasing increments (25 g) of mean enucleated prostate tissue weight on enucleation and morcellation efficiency (g/min). One-way Kruskal–Wallis ANOVA with Dunn’s post hoc test was used, with significant p < 0.05. We included 675 HoLEPs with all comers mean tissue weight resected of 72.1 g (Range 1–448 g), energy used 110.00 kJ (10.73–340 kJ), enucleation time 48.6 min (5–151 min), and morcellation time 10.1 min (0.5–113 min). Average enucleation efficiency increased with increasing prostate size categories (e.g., <25 g–0.48 g/min, >325 g–3.91 g/min) (K-W ANOVA p = 0.004, Dunn’s post hoc p = 0.004). The combined average enucleation and morcellation efficiency was ≥5 g/min between 55 and 271 g. Inefficiency for cases <55 g was driven by enucleation, while >271 g case inefficiency was driven by morcellation. Increasing tissue weight at the time of HoLEP is associated with a linear relationship of increasing enucleation and decreasing morcellation efficiencies.

Preoperative predictors of enucleation time during en bloc 'no-touch' holmium laser enucleation of the prostate

Background

To evaluate preoperative predictors of enucleation time during en bloc ‘no-touch’ holmium laser enucleation of the prostate (HoLEP)

Methods

We enrolled 135 patients with symptomatic benign prostatic hyperplasia (BPH) treated with en bloc ‘no-touch’ HoLEP from July 2017 to March 2019 by a single surgeon. Preoperative, perioperative, and postoperative clinical variables were examined. Stepwise linear regression was performed to determine clinical variables associated with enucleation times.

Result

The average (range) enucleation time was 46.1 (12–220) minutes, and the overall operation time was 71 (18–250) minutes. History of antiplatelet agents, history of urinary tract infection (UTI), and increasing specimen weight were each significantly associated with increasing enucleation time. No category IV complications were recorded, and all complications were evenly distributed among the groups according to the HoLEP specimen weight.

Conclusion

En bloc ‘no-touch’ HoLEP was found to be an efficient and reproducible surgical method for treating BPH. Prostatic gland size was significantly associated with increased enucleation times. Similarly, history of UTI and antiplatelet agents were correlated with increased operative time.

Computer vision detects subtle histological effects of dutasteride on benign prostate

OBJECTIVE

To determine whether a computer vision-based approach applied to haematoxylin and eosin (H&E) prostate biopsy images can distinguish dutasteride-treated tissue from placebo, and identify features associated with degree of responsiveness to 5α-reductase inhibitor (5ARI) therapy.

SUBJECTS AND METHODS

Our study population comprised 100 treatment-adherent men without prostate cancer assigned to dutasteride or placebo in the REDUCE trial, who had slides available from mandatory year-4 biopsies. Half of the men also provided slides from a year-2 biopsy. We obtained 20× whole-slide images and used specialized software to generate a library of 1 300 epithelial and stromal features from objects comprising superpixels and several types of nuclei, including spatial relations among objects between and within each hierarchical level. We used penalized logistic regression and fivefold cross-validation to find optimal combinations of histological features in the year-4 biopsies. Feature data from the year-2 biopsies were fitted to a final model for independent validation. Two pathologists, blinded to treatment, scored each image for focal atrophy and histological features previously linked to 5AR1 treatment.

RESULTS

Consensus classification by pathologists obtained a discrimination accuracy equivalent to chance. A 21-feature computer vision model gave a cross-validation area under the curve of 0.97 (95% confidence interval [CI] 0.95-0.99) in the year-4 biopsies and 0.79 (95% CI: 0.65-0.92) in the set-aside year-2 biopsies. Histology scores were not correlated with change in prostate-specific antigen level, serum dihydrotestosterone level or gland volume. Key features associated with dutasteride treatment included greater shape and colour uniformity in stroma, irregular clustering of epithelial nuclei, and greater variation in lumen shape.

CONCLUSION

The present findings show that a computer vision approach can detect subtle histological effects attributable to dutasteride, resulting in a continuous measure of responsiveness to the drug that could eventually be used to predict individual patient response in the context of BPH treatment or cancer chemoprevention.

The use of 5-alpha reductase inhibitors in the treatment of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is characterized by an enlarged prostate, lower urinary tract symptoms (LUTS), and a decreased urinary flow rate. Common in older men, BPH is a progressive disease that can eventually lead to complications including acute urinary retention (AUR) and the need for BPH-related surgery. Both normal and abnormal prostate growth is driven by the androgen dihydrotestosterone (DHT), which is formed from testosterone under the influence of 5-alpha reductase. Thus, 5-alpha reductase inhibitors (5-ARIs) effectively reduce the serum and intraprostatic concentration of DHT, causing an involution of prostate tissue. Two 5-ARIs are currently available for the treatment of BPH—finasteride and dutasteride. Both have been demonstrated to decrease prostate volume, improve LUTS and urinary flow rates, which ultimately reduces the risk of AUR and BPH-related surgery. Therefore, either alone or in combination with other BPH medications, 5-ARIs are a mainstay of BPH management.

Effect of 5α-Reductase Inhibitors on Sexual Function: A Meta-Analysis and Systematic Review of Randomized Controlled Trials

INTRODUCTION

5α-Reductase inhibitors (5ARIs) are widely used for the treatment of benign prostatic hyperplasia (BPH) and androgenetic alopecia (AGA).

AIM

To review all the available data on the effect of 5ARIs on sexual function and assess whether 5ARIs increase the risk of sexual dysfunction.

METHODS

A systematic search of the literature was conducted using the Medline, Embase, and Cochrane databases. The search was limited to articles published in English and up to October 2015. Article selection proceeded according to the search strategy based on Preferred Reporting Items for Systematic Reviews and Meta-analyses criteria. Data were analyzed using Stata 12.0. A fixed- or a random-effects model was used to calculate the overall combined risk estimates. Publication bias was assessed using Begg and Egger tests.

MAIN OUTCOME MEASURES

Sexual dysfunction, erectile dysfunction, and decreased libido.

RESULTS

After screening 493 articles, 17 randomized controlled trials with 17,494 patients were included. Nine studies evaluated the efficacy of 5ARIs in men with BPH. The other eight reported using 5ARIs in the treatment of men with AGA. The mean age of participants was 60.10 years across all studies. We included 10 trials (6,779 patients) on the efficacy and safety of finasteride, 4 trials (6,222 patients) on the safety and tolerability of dutasteride, and 3 trials (4,493 patients) using finasteride and dutasteride for AGA. The pooled relative risks for sexual dysfunction were 2.56 (95% CI = 1.48-4.42) in men with BPH and 1.21 (95% CI = 0.85-1.72) in men with AGA; those for erectile dysfunction were 1.55 (95% CI = 1.14-2.12) in men with BPH and 0.66 (95% CI = 0.20-2.25) in men with AGA; and those for decreased libido were 1.69 (95% CI = 1.03-2.79) in men with BPH and 1.16 (95% CI = 0.50-2.72) in men with AGA. Estimates of the total effects were generally consistent with the sensitivity analysis. No evidence of publication bias was observed.

CONCLUSION

Evidence from the randomized controlled trials suggested that 5ARIs were associated with increased adverse effects on sexual function in men with BPH compared with placebo. However, the association was not statistically significant in men with AGA. Well-designed randomized controlled trials are indicated to study further the mechanism and effects of 5ARIs on sexual function.

The effect of testosterone treatment on prostate histology and apoptosis in men with late-onset hypogonadism

OBJECTIVES

To investigate the effect of testosterone replacement therapy (TRT) on prostate histology and apoptosis in men with late-onset hypogonadism (LOH).

METHODS

The study included 25 men, having LOH with prostate-specific antigen (PSA) level of 4 ng/ml or less. All patients underwent transrectal ultrasound guided prostate biopsy at baseline, and received testosterone undecanoate treatment for 1 year. Prostate biopsy was repeated at the end of 1 year of testosterone therapy. In addition to clinical and biochemical parameters, prostate histology and apoptotic index (AI) were compared before and after the TRT.

RESULTS

The mean serum total testosterone significantly increased from 178.04 ± 51.92 to 496.28 ± 103.73 ng/dl (p = 0.001). No significant differences were observed in serum total and free PSA level, prostate volume and maximal urinary flow rate. There were also no significant differences in AI, stroma/epithelial cells ratio, Ki-67 positive cells and atrophy score of prostate tissue before and after the TRT.

CONCLUSIONS

This study demonstrated that TRT did not affect serum PSA level, prostate volume and maximal urinary flow rate. This study also suggests that TRT does not cause the risk for prostate cancer development, because of no significant differences in prostate histology after TRT.

Side Effects of 5-Alpha Reductase Inhibitors: A Comprehensive Review

INTRODUCTION

5α-reductase inhibitors (5ARI) include finasteride and dutasteride, and are commonly prescribed in the treatment of benign prostatic hyperplasia and androgenic alopecia. 5ARIs are associated with several known adverse effects (AEs), with varying reported prevalence rates.

AIM

The aim was to review and summarize findings from published literature detailing AEs associated with 5ARI use. A secondary aim was to review potential mechanisms of action, which may account for these observed and reported AEs.

METHODS

A PubMed search was conducted on articles published from 1992 to 2012, which reported AEs with 5ARIs. Priority was given to randomized, placebo-controlled trials. Studies investigating potential mechanisms of action for 5ARIs were included for review.

MAIN OUTCOME MEASURES

AE data reported from available trials were summarized and reviewed.

RESULTS

Reported AEs with 5ARIs include sexual dysfunction, infertility, mood disorders, gynecomastia, high-grade prostate cancer, breast cancer, and cardiovascular morbidity/risk factors, although their true association, prevalence, causality, and clinical significance remain unclear. A pooled summary of all randomized, placebo-controlled trials evaluating 5ARIs (N = 62,827) revealed slightly increased rates over placebo for decreased libido (1.5%), erectile dysfunction (ED) (1.6%), ejaculatory dysfunction (EjD) (3.4%), and gynecomastia (1.3%). The limited data available on the impact of 5ARIs on mood disorders demonstrate statistically significant (although clinically minimal) differences in rates of depression and/or anxiety. Similarly, there are limited reports of reversible, diminished fertility among susceptible individuals. Post-marketing surveillance reports have questioned the actual prevalence of AEs associated with 5ARI use and suggest the possibility of persistent symptoms after drug discontinuation. Well-designed studies evaluating these reports are needed.

CONCLUSIONS

5ARIs are associated with slightly increased rates of decreased libido, ED, EjD, gynecomastia, depression, and/or anxiety. Further studies directed at identifying prevalence rates and persistence of symptoms beyond drug discontinuation are required to assess causality. Trost L, Saitz TR, and Hellstrom WJG. Side effects of 5-alpha reductase inhibitors: A comprehensive review. Sex Med Rev 2013;1:24-41.

Predictors of Enucleation and Morcellation Time During Holmium Laser Enucleation of the Prostate

OBJECTIVE

To examine predictors of enucleation and morcellation times within a large cohort of men undergoing holmium laser enucleation of the prostate (HoLEP) for benign prostatic hypertrophy.

MATERIALS AND METHODS

Preoperative, perioperative, and postoperative clinical characteristics were available from men treated with HoLEP between 1998 and 2013 at Indiana University Health Methodist Hospital. Stepwise linear regression was performed to determine clinical variables which are associated with enucleation and morcellation times.

RESULTS

We identified 960 patients who underwent HoLEP. Average (range) enucleation time was 65.7 (11-245) minutes and morcellation time was 19.7 (3-260) minutes. History of anticoagulation was associated with a small decrease in enucleation time (P = .013) whereas increasing HoLEP specimen weight was associated with increasing enucleation time (P <.001). History of intermittent catheterization, urinary tract infections (UTI), presence of dense prostatic tissue (colloquially referred to as "beach balls"), and increasing specimen weight were associated with increasing morcellation time (P <.05 each). Having HoLEP performed by a less experienced urologist was associated with longer enucleation and morcellation times.

CONCLUSION

Prostate volume is significantly associated with increased enucleation and morcellation times during HoLEP. Additionally, history of UTI and clean intermittent catheterization (CIC) is associated with modest increases in enucleation and morcellation times. Dense enucleated prostate tissue significantly impacts the ability to morcellate effectively. Increasing surgeon experience can significantly improve both enucleation and morcellation efficiency.

A synopsis of drugs currently in preclinical and early clinical development for the treatment of benign prostatic hyperplasia

INTRODUCTION

Benign prostatic hyperplasia (BPH) is a common disease among men and significantly impacts quality of life by causing lower urinary tract symptoms (LUTS). Current medical therapies are not always adequate in controlling LUTS or slowing disease progression, and there is unmet need for new effective therapeutic options.

AREAS COVERED

The authors review the standard current medical therapies for BPH which include the use of α-1 blockers, 5-α reductase inhibitors, combination therapy and PDE inhibitors. Following this, the authors then discuss new therapies that are currently undergoing preclinical and clinical investigation.

EXPERT OPINION

Existing preclinical and clinical trials have highlighted many promising therapies to treat BPH. Further investigation with larger clinical trials is needed to establish these drugs as standard therapies. As the number of drugs in the arsenal against BPH continues to grow, providers and patients will have to engage in a discussion that weighs the risks and benefits of each therapy.

Effects of the 5α-reductase inhibitor dutasteride on rat prostate α1A-adrenergic receptor and its mediated contractility

OBJECTIVE

To clarify the possible interference of the 5α-reductase inhibitor dutasteride with α-adrenergic blockers, whose action is mainly mediated by α1A-adrenergic receptor.

METHODS

Male rats were divided into dutasteride and vehicle-treated groups. The drug treatment group was treated with oral dutasteride 0.5 mg/kg/d, and the control group received vehicle only for 2 months. After the 2-month treatment, the rats' ventral prostate weight changes and the testosterone and dihydrotestosterone levels in the serum were measured. In vitro organ-bath studies, real-time polymerase chain reaction, and tissue-segment binding were performed to determine the expression of α1A-adrenergic receptors and its mediated contractility.

RESULTS

Dutasteride treatment significantly decreased the rats' ventral prostate weight, increased their testosterone levels, and decreased the dihydrotestosterone levels in their serum. There were no marked changes in the α1A-adrenergic receptor messenger ribonucleic acid expression, relative phenylephrine-induced contractility, or nerve-mediated contractility between the groups. Dutasteride treatment caused no marked changes in the relative binding capacity of α1A-adrenergic receptor, whereas it greatly decreased the total protein expression of this subtype and its mediated maximal contraction in the whole ventral prostate.

CONCLUSION

These results suggest that dutasteride does not interfere with α-adrenergic blockers but otherwise has beneficial effects on their actions. Therefore, the long-term administration of the combination of dutasteride with an α-adrenergic blocker might be a better choice for the treatment of lower urinary tract symptoms due to benign prostatic hyperplasia.

Short-term pretreatment with a dual 5α-reductase inhibitor before bipolar transurethral resection of the prostate (B-TURP): evaluation of prostate vascularity and decreased surgical blood loss in large prostates

OBJECTIVE

To investigate if short-term treatment with dutasteride (8 weeks) before bipolar transurethral resection of the prostate (B-TURP) can reduce intraoperative bleeding, as dutasteride a dual 5α-reductase inhibitor (5-ARI) blocks the conversion of testosterone into its active form dihydrotestosterone (DHT), and reduces prostate volume and prostate-specific antigen (PSA) levels, while increasing urinary flow rate.

PATIENTS AND METHODS

In all, 259 patients were enrolled and randomised to two groups: Group A, receiving placebo and Group B, receiving dutasteride (0.5 mg daily for 8 weeks). Blood samples were taken before and after B-TURP for serum chemistry evaluation. In particular we evaluated blood parameters associated with blood loss [haemoglobin (Hb) and haematocrit (Ht)] and prostate vascularity [vascular endothelial growth factor (VEGF) immunoreactivity and microvessel density (MVD) using cluster of differentiation 34 (CD34) immunoreactivity].

RESULTS

Total testosterone, DHT, PSA level and prostate volume were evaluated and with the exception of DHT and PSA level there was no statistically significant differences between the groups. When comparing changes in Hb and Ht between Group A and Group B before and after B-TURP, there was a statistically significant difference only in patients with large prostates of ≥50 mL (ΔHb 3.86 vs 2.05 g/dL and ΔHt 4.98 vs 2.64%, in Groups A and B, respectively). There was no significant difference in MVD and VEGF index in prostates of <50 mL, conversely in large prostates the difference become statistically significant.

CONCLUSIONS

Dutasteride was able to reduce operative and perioperative bleeding only in patients with large prostates (≥50 mL) that underwent B-TURP. Our findings are confirmed by Hb and Ht values reported before and after the B-TURP and reductions in the molecular markers for VEGF and CD34 in the dutasteride-treated specimens.

Is transforming growth factor-β signaling activated in human hypertrophied prostate treated by 5-alpha reductase inhibitor?

Background and Aim. It is well known that androgen deprivation relates to penile fibrosis, so we hypothesize that long-term treatment with 5-alphareductase inhibitors (5ARIs) may increase the risk of fibrosis of prostate. Patients and Methods. Thirty-two BPH patients who underwent transurethral resection of the prostate were enrolled. The patients were divided into two groups: group one, 16 patients underwent TURP who had been treated with tamsulosin for 2 years; group two, 16 patients underwent TURP who had been treated with combination of tamsulosin and dutasteride for at least 1 year. We evaluated the expressions of nNOS, iNOS, eNOS, TGF-β1, TGF-β2, phosphorylated-Smad2/3 (p-Smad2/3), E-cadherin, N-cadherin, and α-smooth muscle actin in the resected prostate tissues by western blotting, and the TGF-β concentration was determined by ELISA kit. Results. The expressions of 3 isoforms of NOS were significantly increased in group 2 except of eNOS in lateral prostate, and the expressions of TGF-β1, TGF-β2, and p-Smad2/3 increased about 2-fold compared with group 1. In group 2, the E-cadherin expression decreased while N-cadherin expression increased significantly. Conclusions. The overexpression of nNOS may contribute to prostate smooth muscle relaxation; however, long-time treatment with 5 ARI increases the risk of fibrosis of prostate.

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.

A retrospective study of clinical outcomes of α-blocker or finasteride monotherapy followed by combination therapy: determination of the period of combination therapy of α-blocker and finasteride

AIMS

We investigated outcomes after discontinuing alpha-blockers or finasteride in patients who initially received combination therapy and compared differences by duration of combination therapy.

METHODS

Patients with international prostate symptom score ≥ 8, serum prostatic-specific antigen (PSA) < 4 ng/ml, prostate volume > 25 cm(3) and combination therapy of alpha-blockers and finasteride for more than 6 months were classified into three groups. Group 1 continued combination therapy; group 2, alpha-blockers monotherapy; and group 3, finasteride monotherapy. All parameters were evaluated before and after changing to monotherapy. Patients who received combination therapy for 6-9 months and those who received combination therapy for longer were comparatively analysed.

RESULTS

Mean age of the 106 patients was 66.9 ± 7.8 years. No significant differences in baseline symptom scores, PSA or prostate volume were found. Following combination therapy, symptom scores, and quality of life (QoL) decreased for all groups. Group 1 maintained decreased PSA and prostate volume, and improved uroflowmetric profiles. No differences in uroflowmetric parameters were found after 6 months. Group 2 maintained improved symptoms, QoL and uroflowmetric profiles, although PSA and prostate volume returned to baseline. Group 3 maintained lowered PSA and prostate volume, whereas Qmax returned to baseline. QoL scores showed no change. Patients who received combination therapy for ≥9 months improved more in symptoms and QoL than those who received shorter combination therapy.

CONCLUSIONS

Discontinuation of alpha-blockers or finasteride after combination therapy for ≥ 6 months maintained improvements in symptoms. The appropriate period of combination therapy was ≥ 9 months.

Benign prostate hyperplasia and stem cells: a new therapeutic opportunity

Most men over 50 experience some lower urinary tract symptoms of nocturia, poor stream, urgency and frequency for urination, due to hyperplastic enlargement of the prostate (benign prostate hyperplasia, BPH). BPH is thought to be a disease with multiple aetiologies including hormone signalling, disruption of proliferation and apoptosis dynamics and chronic inflammation with changes in the morphology and phenotype of the prostate stroma. It has been proposed, recently, that stromal stem cells in prostate may be caused by the development of BPH. This review focuses on this putative role of stromal stem or stem-like cells in the development of BPH and assesses the potential of targeting the stem cells for the treatment of BPH.

A systematic review of the effects and mechanisms of preoperative 5α-reductase inhibitors on intraoperative haemorrhage during surgery for benign prostatic hyperplasia

5α-reductase inhibitors (5α-RIs), including finasteride and dutasteride, are commonly used medical therapies for benign prostatic hyperplasia (BPH). Many studies reported that preoperative 5α-RI had impact on intraoperative haemorrhage during surgery for BPH, but it was still in controversial. So, we conducted a systematic review of the effects and mechanisms of 5α-RIs on intraoperative bleeding for BPH. MEDLINE, EMBASE, the Cochrane Controlled Trail Register of Controlled Trials and the reference lists of retrieved studies were searched in the analysis. Sixteen publications involving 15 different randomized controlled trials (RCTs) and a total of 1156 patients were used in the analysis, including 10 RCTs for finasteride and five RCTs for dutasteride. We found that preoperative finasteride treatment decreases microvessel density (MVD) in resected prostate specimens. Total blood loss, blood loss per gram of resected prostate tissue and decreases in haemoglobin were all greatly reduced in the finasteride group as compared to controls. Dutasteride appeared to have no effect on bleeding. This meta-analysis shows that preoperative finasteride treatment could decrease intraoperative haemorrhage during surgery for BPH. Preoperative dutasteride had no effect on intraoperative haemorrhage, but further high-quality prospective studies are still needed to confirm this observation.

Finasteride for benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH), a non-malignant enlargement of the prostate in aging men, can cause bothersome urinary symptoms (intermittency, weak stream, straining, urgency, frequency, incomplete emptying). Finasteride, a five-alpha reductase inhibitor (5ARI), blocks the conversion of testosterone to dihydrotestosterone, reduces prostate size, and is commonly used to treat symptoms associated with BPH.

OBJECTIVES

To compare the clinical effectiveness and harms of finasteride versus placebo and active controls in the treatment of lower urinary tract symptoms (LUTS).

SEARCH STRATEGY

We searched The Cochrane Library (which includes CDSR (Cochrane Database of Systematic Reviews), DARE (Database of Abstracts of Reviews of Effects), HTA (Heath Technology Assessments), and CENTRAL (Cochrane Central Register of Controlled Trials, and which includes EMBASE and MEDLINE), LILACS (Latin American and Caribbean Center on Health Sciences Information) and Google Scholar for randomized, controlled trials (RCTs). We also handsearched systematic reviews, references, and clinical-practice guidelines.

SELECTION CRITERIA

Randomized trials in the English language with placebo and/or active arms with a duration of at least 6 months.

DATA COLLECTION AND ANALYSIS

JT extracted the data, which included patient characteristics, outcomes, and harms. Our primary outcome was change in a validated, urinary symptom-scale score, such as the AUA/IPSS. A clinically meaningful change was defined as 4 points. We also categorized outcomes by trial lengths of ≤ 1 year (short term) and > 1 year (long term).

MAIN RESULTS

Finasteride consistently improved urinary symptom scores more than placebo in trials of > 1 year duration, and significantly lowered the risk of BPH progression (acute urinary retention, risk of surgical intervention, ≥ 4 point increase in the AUASI/IPSS). In comparison to alpha-blocker monotherapy, finasteride was less effective than either doxazosin or terazosin, but equally effective compared to tamsulosin. Both doxazosin and terazosin were significantly more likely than finasteride to improve peak urine flow and nocturia, versus finasteride. Versus tamsulosin, peak urine flow and QoL improved equally well versus finasteride. However, finasteride was associated with a lower risk of surgical intervention compared to doxazosin, but not to terazosin, while finasteride and doxazosin were no different for risk of acute urinary retention. Two small trials reported no difference in urinary symptom scores between finasteride and tamsulosin. Finasteride + doxazosin and doxazosin monotherapy improved urinary symptoms equally well (≥ 4 point improvement).For finasteride, there was an increased risk of ejaculation disorder, impotence, and lowered libido, versus placebo. Versus doxazosin, finasteride had a lower risk of asthenia, dizziness, and postural hypotension, and versus terazosin, finasteride had a significant, lower risk of asthenia, dizziness, and postural hypotension.

AUTHORS' CONCLUSIONS

Finasteride improves long-term urinary symptoms versus placebo, but is less effective than doxazosin. Long-term combination therapy with alpha blockers (doxazosin, terazosin) improves symptoms significantly better than finasteride monotherapy. Finasteride + doxazosin improves symptoms equally - and clinically - to doxazosin alone. In comparison to doxazosin, finasteride + doxazosin appears to improve urinary symptoms only in men with medium (25 to < 40 mL) or large prostates (≥ 40 mL), but not in men with small prostates (25 mL).Comparing short to long-term therapy, finasteride does not improve symptoms significantly better than placebo at the short term, but in the long term it does, although the magnitude of differences was very small (from < 1.0 point to 2.2 points). Doxazosin improves symptoms better than finasteride both short and long term, with the magnitude of differences ∼2.0 points and 1.0 point, respectively. Finasteride + doxazosin improves scores versus finasteride alone at both short and long term, with mean differences ∼2.0 points for both time points. Finasteride + doxazosin versus doxazosin improves scores equally for short and long term.Drug-related adverse effects for finasteride are rare; nevertheless, men taking finasteride are at increased risk for impotence, erectile dysfunction, decreased libido, and ejaculation disorder, versus placebo. Versus doxazosin, which has higher rates of dizziness, postural hypotension, and asthenia, men taking finasteride are at increased risk for impotence, erectile dysfunction, decreased libido, and ejaculation disorder. Finasteride significantly reduces asthenia, postural hypotension, and dizziness versus terazosin. Finasteride significantly lowers the risk of asthenia, dizziness, ejaculation disorder, and postural hypotension, versus finasteride + terazosin.

The evolutionary impact of androgen levels on prostate cancer in a multi-scale mathematical model

Background

Androgens bind to the androgen receptor (AR) in prostate cells and are essential survival factors for healthy prostate epithelium. Most untreated prostate cancers retain some dependence upon the AR and respond, at least transiently, to androgen ablation therapy. However, the relationship between endogenous androgen levels and cancer etiology is unclear. High levels of androgens have traditionally been viewed as driving abnormal proliferation leading to cancer, but it has also been suggested that low levels of androgen could induce selective pressure for abnormal cells. We formulate a mathematical model of androgen regulated prostate growth to study the effects of abnormal androgen levels on selection for pre-malignant phenotypes in early prostate cancer development.

Results

We find that cell turnover rate increases with decreasing androgen levels, which may increase the rate of mutation and malignant evolution. We model the evolution of a heterogeneous prostate cell population using a continuous state-transition model. Using this model we study selection for AR expression under different androgen levels and find that low androgen environments, caused either by low serum testosterone or by reduced 5α-reductase activity, select more strongly for elevated AR expression than do normal environments. High androgen actually slightly reduces selective pressure for AR upregulation. Moreover, our results suggest that an aberrant androgen environment may delay progression to a malignant phenotype, but result in a more dangerous cancer should one arise.

Conclusions

The model represents a useful initial framework for understanding the role of androgens in prostate cancer etiology, and it suggests that low androgen levels can increase selection for phenotypes resistant to hormonal therapy that may also be more aggressive. Moreover, clinical treatment with 5α-reductase inhibitors such as finasteride may increase the incidence of therapy resistant cancers.

Reviewers

This article was reviewed by Ariosto S. Silva (nominated by Marek Kimmel) and Marek Kimmel.

Prostate magnetic resonance imaging: multiexponential T2 decay in prostate tissue

PURPOSE

To investigate the T2 decay in prostate tissue for multiexponentiality and to assess how the biexponential model relates to established T2W contrast.

MATERIALS AND METHODS

A 32-echo spin-echo sequence was performed on 16 volunteers. Six single-voxel decay curves were sampled from each prostate. Prediction accuracies were assessed by jackknifing for the mono-, bi-, and triexponential models. The differences were evaluated by cross-validated analysis of variance (CVANOVA). Multiple linear regression was performed to assess the relation between parameters in the biexponential model and the contrast in T2W images.

RESULTS

Mono-, bi-, and triexponential models were preferred in 8 (10%), 72 (86%), and 4 (5%) cases, respectively. The biexponential short T2 was 64 msec (range 43 to 92 msec) and the long T2 was 490 msec (range 161 to 1319 msec). The fitted signal fraction, f, of the long T2 component was 27% (range 3% to 80%). The adjusted R(2) was 75.1% for the full regression model and decreased by 0.9%, 1.3%, and 39.2% when short T2, long T2, and f were removed from the model, respectively.

CONCLUSION

Prostatic T2 decay was, in general, biexponential. The differences between the T2 components were large enough for accurate quantification. The T2W image contrast was primarily predicted by the biexponential signal fractions.

Hypertension, RAS, and gender: what is the role of aminopeptidases?

Hypertension is the major risk factor for coronary heart disease, stroke, and renal disease. Also, it is probably the most important risk factor for peripheral vascular disease and vascular dementia. Although hypertension occurs in both men and women, gender differences have been observed. However, whether sex hormones are responsible for the observed gender-associated differences in arterial blood pressure, and which is their mechanism of action, remains unclear. Local and circulating renin-angiotensin systems (RAS) are examples of systems that may be involved in the pathogenesis of hypertension. Classically, angiotensin II (Ang II) has been considered as the effector peptide of the RAS, but Ang II is not the only active peptide. Several of its degradation products, including angiotensin III (Ang III) and angiotensin IV (Ang IV) also possess biological functions. These peptides are formed via the activity of several aminopeptidases. This review will briefly summarize what is known about gender differences in RAS-regulating aminopeptidase activities, their relationship with sex hormones, and their potential role in controlling blood pressure acting through local and circulating RAS.

Prostate cancer prevention: past, present, and future

Prostate cancer is the most common male malignancy and the second or third leading cause of cancer death among men in the West. The descriptive epidemiology of prostate cancer suggests that it is a preventable disease. Prevention has the theoretical advantage of not only saving lives, but also reduce the morbidity of radical prostate cancer therapy. This article reviews the past, present, and future of prostate cancer prevention. In particular, the evidence and scientific data of a variety of prevention strategies are reviewed. Strategies reviewed include dietary fat reduction and supplementation with vitamins D and E, and selenium. Dietary intake of soy, green tea, and tomato-rich products (lycopene) are also reviewed. Data regarding pharmacological intervention with cyclo-oxygenease inhibitors, antiestrogens, and in particular 5-alpha reductase inhibitors are reviewed. The results of the Prostate Cancer Prevention Trial including the controversy surrounding higher-grade cancers among men randomized to finasteride are also summarized. Finally, a variety of trial designs as well as a roster of current phase 2 trials are presented. Probably no cancer is being investigated more thoroughly in the context of prevention as prostate cancer in 2007. Definitive answers to pivotal phase 3 trials will be available in the coming 2 to 7 years.

Detection bias due to the effect of finasteride on prostate volume: a modeling approach for analysis of the Prostate Cancer Prevention Trial

BACKGROUND

The Prostate Cancer Prevention Trial (PCPT) demonstrated a 24.8% reduction in the 7-year prevalence of prostate cancer among patients treated with finasteride (5 mg daily) compared with that among patients treated with placebo; however, a 25.5% increase in the prevalence of high-Gleason grade tumors was observed, the clinical significance of which is unknown. One hypothesized explanation for this increase is that finasteride reduced prostate volume, leading to detection of more high-grade tumors due to increased sampling density. This possibility was investigated in an observational reanalysis of the PCPT data, with adjustment for sampling density.

METHODS

A logistic model for the association of high-grade (Gleason score 7-10) prostate cancer with baseline covariates and/or baseline covariates plus prostate volume and number of cores obtained at biopsy was developed using the placebo group (n = 4775) of the PCPT. This model was then applied to the finasteride group (n = 5123) to compare the predicted and observed numbers of high-grade tumors in that group. In a second approach, odds ratios (ORs) for prostate cancer in the finasteride versus placebo groups calculated from binary and polytomous logistic regression models that contained or excluded covariates for gland volume and number of needle cores were compared.

RESULTS

Median prostate volume was 25% lower in the finasteride group (median = 25.1 cm3) than in the placebo group (median = 33.5 cm3). The logistic model developed in the placebo group showed that the likelihood of detection of high-grade prostate cancer decreased as volume increased (for each 10 cm3 increase in prostate volume, OR = 0.81, 95% confidence interval [CI] = 0.74 to 0.90). Based on this model, 239 high-grade prostate cancers were predicted in the finasteride group, whereas 243 were observed, a non-statistically significant difference. Among all participants, the odds ratios for high-grade cancer in the finasteride versus placebo groups decreased from 1.27 (95% CI = 1.05 to 1.54) with adjustment for baseline covariates to 1.03 (95% CI = 0.84 to 1.26) following additional adjustment for gland volume and number of biopsy cores in binary outcome models and from 1.14 (95% CI = 0.94 to 1.38) to 0.88 (95% CI = 0.72 to 1.09) following these adjustments in the polytomous models.

CONCLUSIONS

Although analyses using postrandomization data require cautious interpretation, these results suggest that sampling density bias alone could explain the excess of high-grade cancers among the finasteride-assigned participants in the PCPT.

Finasteride and doxazosin alone or in combination for the treatment of benign prostatic hyperplasia

Benign prostatic hyperplasia is an increasingly prevalent condition affecting > 50% of men > 65 years of age. Although it is a condition that is unlikely to be life threatening, it can significantly affect quality of life with distressing lower urinary tract symptoms. Increasingly, medical therapy is being used as first-line treatment for men with moderate-to-severe lower urinary tract symptoms. Two main pharmacological classes of drugs are used: 5alpha-reductase inhibitors and alpha-1 selective blockers. Both these classes of drugs have shown good tolerability and clinical efficacy. This article examines the potential benefit of the use of combination therapy. In particular, what is the evidence for using doxazosin and finasteride therapy together?

Diagnosis of prostatic carcinoma after therapy

CONTEXT

Prostate cancer is the most common cancer of men in the United States and is third only to lung and colon cancer as a cause of cancer death. In 2006, 27,350 Americans will die of prostate cancer, and 234,460 new cases will be diagnosed. Treatment changes in the benign and cancerous prostate create diagnostic challenges in pathologic interpretation, particularly in needle biopsy specimens and in evaluation of extraprostatic metastases.

OBJECTIVE

To summarize therapy-related pathologic findings in the prostate with emphasis on recognition of treated adenocarcinoma.

DATA SOURCES

Extensive review of published literature and the authors' experience.

CONCLUSIONS

Following therapy for prostate cancer, it is critical that the clinician provide the pertinent history of androgen deprivation or radiation therapy to assist the pathologist in rendering the correct diagnosis.

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

PURPOSE

We determined the effects of dutasteride on transition and peripheral zone volume, and the clinical value of the transition zone index in men with benign prostatic hyperplasia.

MATERIALS AND METHODS

A total of 2,802 men 50 years or older with diagnosed benign prostatic hyperplasia, American Urological Association symptom index score 12 or greater, total prostate volume 30 cc or greater, prostate specific antigen 1.5 ng/ml or greater and 10 ng/ml or less, and peak urinary flow rate 15 ml per second or less were randomized to receive 0.5 mg dutasteride daily or placebo for 2 years. Total prostate and transition zone volume was measured with transrectal ultrasound at baseline and 4 times during the 2-year period. Peripheral zone volume (total prostate volume minus transition zone volume) and the transition zone index (transition zone volume/total prostate volume) were calculated. Patients were stratified into tertiles according to baseline total prostate and transition zone volume, and the transition zone index.

RESULTS

At 24 months dutasteride significantly decreased total prostate volume from baseline (p <0.0001). There were similar decreases in transition and peripheral zone volume (approximately 25%). In men receiving placebo high baseline total prostate and transition zone volume, and transition zone index were associated with poor 2-year outcomes, ie a low peak urinary flow rate, high American Urological Association symptom index scores, and an increased frequency of acute urinary retention and benign prostatic hyperplasia related surgery. Improvements in outcomes with dutasteride vs placebo were greatest in men with the highest baseline total prostate and transition zone volume, and transition zone index. In men with low (30 to less than 42 cc) and intermediate (42 to less than 58 cc) baseline total prostate volume the benefits of dutasteride therapy were only significant in the intermediate (0.4 to less than 0.55) and high (0.55 to less than 1.0) transition zone index tertiles.

CONCLUSIONS

Total prostate and transition zone volume, and the transition zone index are directly related to benign prostatic hyperplasia progression. The transition zone index may add value to transition zone volume alone for predicting outcomes. Dutasteride decreased transition and peripheral zone volume equally, supporting a known therapeutic role in benign prostatic hyperplasia and a possible preventive role in prostate cancer.

Drug Insight: 5alpha-reductase inhibitors for the treatment of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a common problem among older men, which is characterized by an enlarged prostate, lower urinary tract symptoms, and decreased flow of urine. It is a progressive disease that can lead to complications such as acute urinary retention (AUR) or a need for BPH-related surgery in some men. Dihydrotestosterone is the primary androgen involved in both normal and abnormal prostate growth and 5alpha-reductase inhibitors (5ARIs) inhibit the conversion of testosterone to dihydrotestosterone. There are two 5ARIs licensed for the treatment of BPH; dutasteride, which inhibits both type 1 and type 2 isoenzymes of 5alpha reductase, and finasteride, which inhibits the type 2 isoenzyme. Both 5ARIs have been shown to decrease prostate volume, improve urinary flow and lower urinary tract symptoms and reduce the risk of AUR and BPH-related surgery. The prevention of disease progression, by treating the underlying cause, and the alleviation of symptoms are important aims of BPH therapy. 5ARIs are the only currently available medical therapy that can reduce the risk of AUR and BPH-related surgery while providing long-term symptom control. This provides a mandate for their use in men with enlarged prostates (volume >or=30 ml), who are at increased risk of disease progression.

Prevention of benign prostatic hyperplasia disease

PURPOSE

We reviewed the evidence that benign prostatic hyperplasia is a progressive condition and men at risk for benign prostatic hyperplasia disease can be identified, treated and protected to a meaningful extent regardless of symptom status.

MATERIALS AND METHODS

The MEDLINE database was searched in 4 areas of interest relating to benign prostatic hyperplasia, including 1) progression of clinical manifestations with age, especially in regard to baseline symptom status, 2) the incidence of complications due to disease progression, 3) the use of predictive factors that may help identify men at risk for disease progression and 4) the prevention of benign prostatic hyperplasia disease with medical therapy.

RESULTS

Tissue changes in the prostate (benign prostatic hyperplasia) are inevitable consequences of aging. However, benign prostatic hyperplasia disease, which we define as a life altering urinary condition requiring medical intervention, is predictable and preventable. Benign prostatic hyperplasia disease progression is associated with increasing prostate volume, decreasing urinary flow, symptomatic deterioration often to the point of major life-style interference and serious complications, eg acute urinary retention and the need for surgery. The risk of benign prostatic hyperplasia disease progression was found to be directly related to prostate volume and its surrogate marker, serum prostate specific antigen, after prostate cancer is excluded. Other factors, eg baseline symptoms and the flow rate, were found to be less relevant compared with prostate specific antigen greater than 1.5 ng/ml for predicting benign prostatic hyperplasia disease morbidity.

CONCLUSIONS

Men at risk for benign prostatic hyperplasia disease can be identified using prostate specific antigen greater than 1.5 ng/ml as a surrogate marker of prostate volume. In men at risk with prostate specific antigen greater than 1.5 ng/ml 5alpha-reductase inhibitors have potential value for benign prostatic hyperplasia disease prevention regardless of symptom status.

Should finasteride be used to prevent prostate cancer?

Prostate cancer is an important public health problem. Chemoprevention offers an attractive solution because it may lead to decreased disease-specific mortality. Furthermore, because many men are treated radically for prostate cancers that pose little or no threat to life, chemoprevention may also provide an excellent strategy for diminishing treatment-related costs and adverse effects such as erectile and urinary dysfunction. The Prostate Cancer Prevention Trial was a 7-year randomized study of finasteride versus placebo among men aged older than 55 years. All men were intended to have a prostate biopsy at study conclusion. At trial's end, there was a 25% reduction in period prevalence in all prostate cancers (24.4% for placebo vs 18.4% for finasteride). This represents a 6% absolute risk reduction. A larger number of higher-grade cancers were noted among men randomized to finasteride, which post hoc analyses and studies suggest are almost certainly related to previously unrecognized biases in trial design. There continues to be great debate as to the clinical significance of the cancers prevented. It is our opinion that among men who warrant 5-alpha reductase inhibitors (5ARIs) as part of their benign prostatic hyperplasia regimen, cancer prevention should be recognized as an additional benefit of treatment. Furthermore, men with high risk of clinically significant prostate cancer, such as significant family history, abnormal prostate biopsy histologies, and African descent, should be made aware of these findings. Men with significant anxiety or concern about prostate cancer should also be made aware of the risks and benefits of this therapy. Additional trials of antiestrogens, micronutrients, and other 5ARIs, which will mature over the next 2 to 5 years, will better define the role of 5ARIs in prostate cancer chemoprevention.

The effects of 5alpha-reductase inhibitors on the natural history, detection and grading of prostate cancer: current state of knowledge

PURPOSE

The Prostate Cancer Prevention Trial (PCPT) showed that the 5alpha-reductase inhibitor (5ARI) finasteride significantly decreased the 7-year period prevalence of prostate cancer vs placebo. However, Gleason score 7-10 tumors were significantly more common in the finasteride vs the placebo group. We considered data on the effects of 5ARIs on prostate cancer natural history and detection.

MATERIALS AND METHODS

A detailed review was performed of the literature identified from the MEDLINE database examining the effects of 5ARIs on prostate cancer prevalence and tumor histopathology.

RESULTS

In PCPT there were fewer biopsies performed for cause in the finasteride vs the placebo group and the proportion of high grade tumors in the treatment groups did not diverge with time. Given that finasteride has an effect on prostate specific antigen and prostate volume, which are key factors in triggering prostate biopsies, they may be significant confounders of Gleason score results. Prostate shrinkage in the finasteride treated group may minimize biopsy sampling error. Furthermore, histological studies have shown that 5ARIs have a significant effect on prostate architecture, which can make the interpretation of prostate specimens in men treated with 5ARIs difficult. Further evaluation of PCPT findings will help determine the true nature of these observations.

CONCLUSIONS

5ARIs decrease the risk of prostate cancer but also alter the detection of disease through effects on prostate specific antigen, and prostate volume and histology. The weight of evidence suggests an artifactual effect of finasteride on Gleason grading in the PCPT. The role of 5ARIs for prostate cancer chemoprevention needs further examination before it can be considered for wide recommendation.

Chemoprevention of prostate cancer with finasteride

Prostate cancer is a significant cause of disease and death, making it an attractive target for chemoprevention. The association between lifetime exposure to dihydrotestosterone and risk of developing prostate cancer suggests that chemoprevention is possible with 5alpha-reductase inhibition. The recently completed Prostate Cancer Prevention Trial indicates that chemoprevention is possible with the 5alpha-reductase inhibitor finasteride. Development of a cost-effective chemoprevention strategy for prostate cancer is evolving, and is expected to have significant positive economic and public health benefits.

Use of 5α-reductase inhibitors to prevent benign prostatic hyperplasia disease

A histologic change in the prostate, benign prostatic hyperplasia (BPH), is a normal part of aging. However, BPH disease, defined here as a life-altering urinary condition caused by BPH requiring prompt medical intervention, is a serious medical disorder associated with major complications, surgical intervention, and severe lifestyle interference. BPH disease is preventable. The rationale for BPH disease prevention rests on four pillars of evidence: (1) BPH disease generally is a progressive disorder; (2) complications and severe lifestyle interference from BPH disease are common and serious; (3) men at greatest risk of BPH disease can be identified using prostate-specific antigen (PSA) level higher than 1.5 ng/mL as a surrogate marker for an enlarged prostate; and (4) 5alpha-reductase inhibitors (5ARIs) reduce the primary androgen responsible for prostate growth (dihydrotestosterone), shrink the prostate, and arrest the disease process regardless of symptom status. Thus, we now can identify men with an enlarged prostate at risk for BPH disease who may be candidates for preventive therapy with 5ARIs, regardless of urinary symptoms or bother.

Finasteride targets prostate vascularity by inducing apoptosis and inhibiting cell adhesion of benign and malignant prostate cells

BACKGROUND

This study investigated the effects of finasteride, a 5alpha-reductase inhibitor, clinically used for the treatment of benign prostatic hyperplasia (BPH) on prostate tumor vascularity, apoptosis, and cell adhesion in situ and in vitro.

METHODS

Prostate specimens from BPH patients treated with finasteride for 1-12 months (n = 13), or without finasteride treatment (n = 14), were evaluated for apoptosis (TUNEL assay), microvessel density (Factor VIII), and prostate specific antigen (PSA) immunoreactivity. In vitro, the effect of finasteride was investigated in benign prostate cells, BPH-1, and its tumorigenic derivatives, CAFTD-01 and CAFTD-03, using Hoechst staining and cell adhesion assays.

RESULTS

A significant increase in the apoptotic index, and reduced microvessel density and PSA expression were detected in prostates from finasteride-treated patients, compared to controls (P < 0.01). In vitro finasteride led to a significant decrease in prostate epithelial cell adhesion (P < 0.05).

CONCLUSIONS

Finasteride can induce prostate apoptosis and reduce tissue vascularity by inhibiting epithelial cell adhesion. This evidence supports that finasteride has apoptotic and anti-angiogenic effects against benign and malignant prostate.

Pharmacokinetic parameters as a potential predictor of response to pharmacotherapy in benign prostatic hyperplasia: a preclinical trial using dynamic contrast-enhanced MRI

We sought to assess the possibility of using pharmacokinetic parameters as a predictor of response to benign prostatic hyperplasia (BPH) pharmacotherapy via a randomized, placebo-controlled, animal preclinical trial using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Twelve male beagles with BPH were enrolled in a preclinical experimental drug trial and divided into two randomized groups with six beagles each: one drug (finasteride) group and one placebo (control) group. Two baseline MRI examinations and three follow-ups during treatment were performed on a clinical 1.5-T MRI system using axial T1- and T2-weighted magnetic resonance images for prostate volume measurement and DCE-MRI for the assessment of prostate microcirculation. A total of 0.2 mmol/kg body weight of the Gd-based contrast agent was administered with an injection rate of 0.2 ml/s. The pharmacokinetic parameters, maximum enhancement ratio (MER), transfer constant and rate constant, were assessed to characterize the microcirculation in the parenchymal zone. The time-signal intensity curve from the external iliac artery was used as the arterial input function. The correlation between baseline evaluations (prostate volume and pharmacokinetic parameters) and therapy-induced prostate volume changes under finasteride treatment were assessed. The changes in prostate volume at the end of the trial exhibited a significant linear correlation to the initial parenchymal MER (P < .02) in the finasteride group. Larger prostate volume reductions coincided with smaller initial parenchymal MER. These findings show considerable promise of using parenchymal MER as a predictor of response to BPH pharmacotherapy with finasteride.

Effects of finasteride on the vascular surface density, number of microvessels and vascular endothelial growth factor expression of the rat prostate

INTRODUCTION

Finasteride is a 5-alpha-reductase inhibitor used in the medical treatment of benign prostatic hyperplasia (BPH) and appears to be effective in treating prostatic bleeding secondary to BPH. The exact mechanism of this effect is not known. The aim of this study was to evaluate the effects of finasteride on the vascular surface density (VSD), number of microvessels (NVES) and vascular endothelial growth factor (VEGF) expression of the rat prostate.

MATERIALS AND METHODS

Nineteen adult male rats were used. Finasteride was given to 14, and there were 5 in the control group. Finasteride 80 mg/kg was administered daily via orogastric tube as a suspension for three months. Rats were sacrificed and vascular structures of the prostates were labelled immunohistochemically using CD31 antibodies. VSD and NVES of the prostates were assessed by means of a peroxidase labeled streptavidin-biotin method. VEGF expression was examined by immunohistochemistry using VEGF monoclonal antibody.

RESULTS

Mean prostatic weights were decreased significantly in rats given finasteride (p=0.0001). Although an increase in VSD was detected in the finasteride group it was not significant (p=0.26). NVES was significantly increased in the finasteride group (p=0.033). No significant difference was detected between the two groups in terms of VEGF expression (p=0.48).

CONCLUSION

Finasteride does not seem to decrease VSD, NVES and VEGF expression at the level of the rat prostate. The effect of reduction of bleeding in BPH is likely to be due to its effect on shrinking glandular hyperplasia which might enhance vessel wall stability rather than decreasing overall vascularity.

Prostate-specific antigen changes as a result of chlormadinone acetate administration to patients with benign prostatic hyperplasia: A retrospective multi-institutional study

BACKGROUND

Antiandrogens used to treat benign prostatic hyperplasia (BPH) may affect the diagnosis of prostate cancer by decreasing serum prostate-specific antigen (PSA) values. We conducted a retrospective survey of BPH patients treated with chlormadinone acetate (CMA) and analysed the effect of CMA on their PSA values.

METHODS

A chart-based, retrospective, multi-institutional survey of clinically diagnosed patients with BPH who had been treated with CMA (Prostal; 50 mg/day) was conducted. The patients were divided into three groups according to their baseline PSA values: <4 ng/mL, Group I; >or=4 ng/mL and <10 ng/mL, Group II; and >or=10 ng/mL, Group III. The changes in the PSA values from baseline after 16, 26, and 52 weeks of CMA therapy were predicted using a nonlinear regression model analysis.

RESULTS

Data from 192 of the 303 enrolled patients were analysed. The predicted percent changes from baseline among all patients after 16, 26, and 52 weeks of treatment were -49.6%, -49.8%, and -49.9%, respectively. The corresponding values were -42.4%, -43.7% and -43.8% in Group I; -57.4%, -58.4% and -58.5% in Group II; and -50.6%, -50.6% and -50.6% in Group III, respectively.

CONCLUSION

The PSA values reached a nadir, approximately -50% of the baseline, after 16 weeks of CMA administration and remained at the same level thereafter. When CMA is used to treat BPH patients, the possibility of abnormal increases in PSA associated with prostate cancer must be considered; if prostate cancer is suspected, prompt testing, including a biopsy, should be performed.

Assessing Benefit and Risk in the Prevention of Prostate Cancer: The Prostate Cancer Prevention Trial Revisited

Purpose

The Prostate Cancer Prevention Trial demonstrated a 25% reduction in period prevalence of prostate cancer in men randomly assigned to 5 mg/d of finasteride. However, widespread use of finasteride for prevention is inhibited by the observed increased risk of high-grade disease. We present a model of risk and benefit that estimates the potential effects of histologic artifact in the assignment of excess risk for high-grade disease and the possible effect of overdetection bias introduced by finasteride-induced volume reduction.

Methods

The absolute benefit/absolute risk ratio of finasteride use was estimated by calculating the ratio of absolute risk reduction in the finasteride arm to the absolute risk of excess high-grade cancers. This ratio was recalculated for assumptions that 10%, 25%, or 50% of the excess high-grade cancers were due to histologic artifact, and that there was a 25% overdetection bias in the finasteride arm.

Results

For all cancers the absolute benefit/absolute risk ratio increased from 4.6:1 to 5.1:1, 6.2:1, and 9.2:1 for assumptions of 10%, 25%, or 50% histologic artifact, respectively. The ratio increased from 4.6:1 to 8.2:1 for the assumption of 25% overdetection bias, and to 9.1:1, 10.9:1, and 16.3:1 for combined assumptions of 25% overdetection bias and 10%, 25%, or 50% histologic artifact, respectively.

Conclusion

The adoption of a prevention strategy hinges on potential benefits weighed against potential risks. This model demonstrates the magnitude of effect for a hypothesized range of histologic artifact and overdetection bias on the assessment of risk versus benefit for finasteride.

The finasteride prostate cancer prevention trial (PCPT) – What have we learned?

In 2003, the first of two large NCI-sponsored prostate cancer chemoprevention trials was reported. The prostate cancer prevention trial (PCPT) demonstrated a 24.8% reduction in the prevalence of prostate cancer in men taking finasteride 5mg/d for 7 years. However, despite the overall reduced risk of prostate cancer, men in the finasteride-treated arm of the study were more likely to develop high-grade disease. This article examines some of the controversies aroused by the PCPT and evaluates some of the arguments that have been advanced in an attempt to explain some of the unexpected outcomes of the study. In addition, some of the recent studies assessing the potential impact of an effective chemopreventive strategy on population mortality are reviewed. To conclude, there is some discussion of factors, which need to be openly discussed with male patients who might be considered for finasteride therapy.

Measurement of the mechanical characteristics of benign prostatic tissue: A Novel method for assessing benign prostatic disease

OBJECTIVES

To investigate the relationship between the morphology and the mechanical properties of benign prostatic tissues measured in vitro.

METHODS

Fresh tissue specimens were collected from 17 patients undergoing transurethral resection of the prostate for benign prostatic obstruction. Individual tissue specimens underwent immediate mechanical testing, by applying a dynamic compressive strain to the samples. The amplitude ratio (E*) and phase difference (tan delta), measures of tissue elastic and viscous components, were derived. Individual sections from the processed specimens underwent immunohistochemical staining and computerized image analysis to measure the morphologic characteristics of each transurethral resection of the prostate chipping. Correlations between the morphologic and mechanical measurements were assessed.

RESULTS

A strong positive correlation was found between prostatic smooth muscle content and (E*) (R2 = 0.58, P = 0.009).

CONCLUSIONS

The results of this study have demonstrated that strong correlations exist between prostatic tissue morphology and mechanical characteristics. We believe that the ability to quantify prostatic tissue mechanical characteristics in vivo may be of clinical benefit in the future assessment and treatment of benign prostatic disease.

Stromal-epithelial measurements of prostate cancer in native Japanese and Japanese-American men

We measured the histologic stromal and epithelial tissue components of the benign (normal) and malignant tissue compartments of Japanese-Americans (J-A) and native Japanese (NJ) men living in Japan. The patient cohort included 25 NJ men undergoing radical prostatectomy (RP) in Nagoya, Japan and 25 J-A (second or third generation US born). We conducted tissue image quantitation (in-house image software) of the stromal and epithelial compartments in malignant and adjacent normal tissue areas from a tissue microarray (TMA) selected from radical prostatectomy (RP) blocks. Stromal-epithelial (S-E) areas were determined using immunohistochemical stains for CAM-5.2 epithelial cytokeratin marker and the Masson trichrome stain to measure the stroma component. We observed differences in the volumes of normal and cancer epithelium and stroma within both the J-A and NJ study populations (P<0.01). Only the individual average cancer epithelium (CE) volume (JA=24.1 vs NJ=29.9) differed significantly between the NJ and J-A study populations (P=0.03). Consequently, the S-E ratio in NJ group was significantly different from that of J-A population (P=0.05). The decrease in S-E ratio noted in the malignant tissues of NJ prostate tissue may provide a biological marker for differentiation of the two groups and suggests a need for further investigations into the molecular basis for these histologic differences.