The effect of finasteride on the risk of acute urinary retention and the need for surgical treatment among men with benign prostatic hyperplasia. Finasteride Long-Term Efficacy and Safety Study Group

5alpha-reductase inhibition for men with enlarged prostate

PURPOSE

Increasingly, men with lower urinary tract symptoms (LUTS) are seeking treatment in the primary care setting. This article reviews the use of alpha-blockers and 5alpha-reductase inhibitors (5ARIs) in the management of LUTS and enlarged prostate.

DATA SOURCES

Information is based on a critical review of the published literature. Relevant studies were identified using MEDLINE and review of reference lists of published studies.

CONCLUSIONS

Enlargement of the prostate is a common occurrence among aging men. Nurse practitioners (NPs) are in a unique, frontline position to evaluate symptoms and bother and to recommend appropriate treatment of patients with enlarged prostate. Both alpha-blockers and 5ARIs are effective at reducing symptoms in the short term. However, only the 5ARIs impact disease progression and maintain improvement in symptoms in the long term.

IMPLICATIONS FOR PRACTICE

NPs play an important role in assessing and treating LUTS in men with enlarged prostate. When treating men with LUTS, assess the severity of symptoms and the extent of prostate enlargement. For symptomatic men with enlarged prostate, long-term therapy with 5ARIs should be considered to treat symptoms as well as address the disease progression.

Acute urinary retention in benign prostatic hyperplasia: Risk factors and current management

Acute urinary retention (AUR) is one of the most significant, uncomfortable and inconvenient event in the natural history of benign prostatic hyperplasia (BPH). The immediate treatment is bladder decompression using urethral or suprapubic catheterization. Several factors have been identified that are associated with or precipitate AUR. It is useful to classify AUR as BPH-related or not, than spontaneous or precipitated when the initial management is considered. Use of prophylactic 5 a-reductase inhibitors can prevent AUR in men with BPH having moderate to severe lower urinary tract symptoms and large prostate size. Alpha blockers can prevent AUR in symptomatic BPH patients and also facilitate catheter removal following episodes of spontaneous AUR. Anticholinergics can be safely combined with alpha blockers in symptomatic BPH patients without increasing the risk of AUR. Surgical treatment carries a higher rate of morbidity and mortality in men presenting with AUR compared to those presenting with symptoms alone. Urgent prostatic surgery after AUR is associated with greater morbidity and mortality than delayed prostatectomy. Alpha blockers mainly help to delay the surgery and may avoid surgery altogether in a subgroup of patients. TURP remains the "gold standard" if a trial without catheter fails. Alternative minimally invasive procedures can be considered in poor-risk patients, but its value is yet to be established.

Managing the progression of lower urinary tract symptoms/benign prostatic hyperplasia: therapeutic options for the man at risk

There are two fairly divergent reviews in this month's issue. The first is a paper which concentrates on the progression of LUTS and BPH. Previous papers on LUTS and BPH were focused on changes in urinary flow rates and symptom scores, a rather static view of things. The first author in this review introduced the concept of dynamic variables in LUTS and BPH, and this, along with the idea of progression of the disease which the MTOPS study brought to our notice, has lead to a major change to our approach to trials of therapy in LUTS and BPH. The second review is really statement of a theory, an expression of a concept being proposed by the author, which hopefully will be of interest to the reader. In benign prostatic hyperplasia (BPH), increased prostate volume has been shown to be associated with future symptom deterioration and progression to acute urinary retention (AUR) or BPH-related surgery. Dihydrotestosterone (DHT) is the primary androgen responsible for prostate growth. Inhibition by 5alpha-reductase inhibitors (5-ARIs) of the enzyme responsible for the production of DHT decreases prostate volume. This translates to an overall improvement in symptoms and a reduction in the risk of AUR and/or BPH-related surgery. Selective blockage of alpha(1)-adrenoceptors, principally in the region of the prostate, results in rapid symptom relief for the patient but this does not translate into a long-term reduction in the risk of AUR or BPH-related surgery. Given their different modes of action the rationale has always existed for using 5ARIs and alpha-blockers together in men deemed to be both symptomatic and at risk of progression. The factors that predict this progression and the methods available to reduce the risk of it occurring are the subjects of this review.

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.

Prevalence of lower urinary tract symptoms and prostate enlargement in the primary care setting

PURPOSE

Men with lower urinary tract symptoms (LUTS) from benign prostatic hyperplasia often do not discuss their symptoms with their primary care physicians (PCPs). The primary objectives of this study were to estimate the prevalence of LUTS, prostate enlargement, and prostate-specific antigen (PSA) > or = 1.5 ng/ml in men visiting their PCP and to assess patients' intent to discuss LUTS with their PCP.

METHODS

Men over age 50 presenting for a routine office visit at one of six PCP offices during the 8-week data collection period were invited to participate in this cross-sectional study. Men with prostate cancer, bladder cancer, indwelling urethral catheter or previous pelvic irradiation were excluded. Four hundred and forty-four men were enrolled and completed a self-administered questionnaire [including the International Prostate Symptom Score (IPSS)], provided a blood sample for PSA, and underwent a digital rectal examination (DRE), with the prostate classified as enlarged or non-enlarged by their PCP.

RESULTS

Forty-two per cent of men had IPSS > 7; 48% had an enlarged prostate based on DRE and 43% had PSA > or = 1.5 ng/ml. Twenty-nine per cent (n = 129) of men had IPSS > 7 and enlarged prostate or PSA > or = 1.5 ng/ml. Of these men, 33% (n = 42) intended to discuss their symptoms with their PCP.

CONCLUSIONS

Although a significant percentage of men in this older population had enlarged prostate and LUTS, only one-third of them intended to discuss their symptoms with their physician. PCPs may need to increase efforts to detect LUTS and enlarged prostate in older men.

Advances in the development of hormonal modulators for the treatment of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a leading disorder of the ageing male population and is characterized by a progressive enlargement of the prostate, resulting in the obstruction of the proximal urethra and hence the disturbance in normal urinary flow and further quality of life of the patients. Therefore, there is an imperative need to develop a therapeutic modality to combat the overgrowth of the prostate with improvements in both the urinary flow rate and the quality of life of the patients. At present, alpha-blockers, which act on the dynamic component of the disease to regulate the increased adrenergic tone of the lower urinary tract smooth muscles, and 5-alpha-reductase inhibitors, which control the overgrowth of the prostate and hence static component by regulating the levels of androgens, are the mainstay of therapies for the treatment of BPH and associated lower urinary tract symptoms. However, each target class has its own limitations in terms of compromised efficacy or tolerability. Therefore, it is pertinent to have an effective and safe therapeutic modality for the further improvement of life of the geriatric male population. Hormone modulators, which regulate the overgrowth of the prostate, represent one of the important categories that have been explored and that is still undergoing certain investigations towards the development of a therapeutic entity for the treatment of BPH. The key lies in achieving the differentiation in terms of improved tolerability with comparable or better efficacy over the existing class of drugs. Gonadotropin receptor modulators and vitamin D receptor agonists may represent promising druggable targets in this therapeutic area, due to the availability of proof of principles and concepts in preclinical animal models and human subjects.

A review of combination therapy in patients with benign prostatic hyperplasia

BACKGROUND

Trials of monotherapy with alpha(1)-adrenergic-receptor antagonists (alpha(1)ARAs) and 5 alpha-reductase inhibitors (5ARIs) have found that the former drug class is effective in managing benign prostatic hyperplasia (BPH)-related lower urinary tract symptoms (LUTS) and improving the maximal urinary flow rate in shortand long-term treatment, regardless of prostate size, whereas the latter drug class is effective in reducing prostate size and preventing disease progression in longer-term treatment. The differing mechanisms of action and areas of efficacy of these 2 drug classes make them promising candidates for combination therapy.

OBJECTIVE

This article reviews key trials of monotherapy and combination alpha(1)ARV5ARI therapy in the treatment and prevention of BPH-related voiding dysfunction.

METHODS

MEDLINE (1976-2006) and the Cochrane Central Register of Controlled Trials (1976-2006) were searched for relevant clinical trials and reviews using the terms benign prostatic byperplasia, lower urinary tract symptoms, LUTS, alpha-adrenergic-receptor antagonists, alpha-blockers, 5 alpha-reductase inhibitors, combination therapy, MTOPS, SMART, PREDICT, adverse events, alfuzosin, doxazosin, tamsulosin, terazosin, dutasteride, and finasteride. Abstracts from selected professional conferences also were reviewed.

RESULTS

Three previous trials of alpha(1)ARA/5ARI therapy found no therapeutic benefit for combination therapy relative to monotherapy, but their conclusions were limited to some extent by their designs, particularly the duration of treatment. Data from the Medical Therapy of Prostatic Symptoms (MTOPS) study, however, indicated a potential role for long-term use of alpha(1)ARA/5ARI therapy, particularly in patients with greater symptom severity (mean score of 17 on the American Urological Association symptom index), larger prostate volume (mean, 32 g), and higher prostate-specific antigen (PSA) levels (>1.5 ng/mL) at baseline. In the MTOPS study, combination therapy with the alpha(1)ARA doxazosin and the SARI finasteride was significantly more effective than either component alone in reducing BPH-related symptoms (P=0.006 vs doxazosin monotherapy; P<0.001 vs finasteride monotherapy) and lowering the rate of overall clinical progression (P<0.001 vs either monotherapy). In addition, there are data from a subgroup analysis of MTOPS suggesting that the presence of prostatic inflammation may indicate a greater likelihood of treatment efficacy with combination alpha(1)ARA/5ARI therapy.

CONCLUSIONS

The available data suggest that combination alpha(1)ARA/5ARI therapy is beneficial in the treatment of BPH and the associated symptoms. The greatest efficacy was evident in patients with an enlarged prostate, more severe symptoms, and higher PSA levels. There are limited data suggesting that the presence of prostatic inflammation may indicate a greater likelihood of treatment efficacy with combination therapy.

Intravesical Prostatic Protrusion is Better Than Prostate Volume in Predicting the Outcome of Trial Without Catheter in White Men Presenting With Acute Urinary Retention: A Prospective Clinical Study

PURPOSE

Trial without catheter after a short course of an alpha-blocker in men presenting with acute urinary retention is successful in up to 50% of cases. The ability to better predict outcome could avoid a trial without catheter for some men. Intravesical prostatic protrusion and not prostate volume has been shown to predict trial without catheter outcome in an Asian cohort. We investigated the relationship between the outcome of trial without catheter and prostate volume and intravesical prostatic protrusion in white men given alpha-blockers before a trial without catheter.

MATERIALS AND METHODS

Consecutive men 50 years old or older presenting with acute urinary retention were prospectively recruited based on strict selection criteria. At presentation factors thought to precipitate acute urinary retention were treated, alpha-blocker therapy started and the patient brought back for a trial without catheter after 2 weeks. Prostate volume and intravesical prostatic protrusion were measured by standard transrectal ultrasonography.

RESULTS

Of 121 men presenting with acute urinary retention 57 fulfilled the study selection criteria. Mean (+/- SD) age, prostate volume and intravesical prostatic protrusion of recruited men were 70 +/- 9.2 years, 69.7 +/- 36.3 ml and 12.8 +/- 10.1 mm, respectively. A total of 25 men (43.9%) had a successful trial without catheter. Mean intravesical prostatic protrusion was significantly smaller in those who had a successful trial without catheter (7.2 vs 16.5 mm, 95% CI 4.5-14, p <0.001). With intravesical prostatic protrusion correlating well with prostate volume (r = 0.588), mean prostate volume was also smaller in men with a successful trial without catheter, albeit with a smaller effect size. Men with an intravesical prostatic protrusion of 10 mm or less, compared to those with a larger intravesical prostatic protrusion, were 6 times more likely to have a successful trial without catheter.

CONCLUSIONS

In this cohort presenting with acute urinary retention related to benign prostatic hyperplasia and receiving alpha-blockers before a trial without catheter, intravesical prostatic protrusion appears to strongly predict the outcome of a trial without catheter. A trial without catheter is more likely to fail in patients with intravesical prostatic protrusion larger than 10 mm.

Acute urinary retention: medical management and the identification of risk factors for prevention

Male lower urinary tract symptoms associated with benign prostatic hyperplasia can be progressive in some patients and lead to adverse consequences such as acute urinary retention (AUR), which might require prostate surgery. This Review identifies baseline and dynamic variables that have been recognized as risk factors that might predispose men to AUR. Evidence for the use of medical therapy to reduce the risk of benign prostatic hyperplasia progression, which might prevent AUR, has been critically evaluated. The literature describing the pharmacological management of men with AUR, and in those who have successfully voided after removal of a catheter, has been critically appraised in this article.

Identification of the patient with enlarged prostate: diagnosis and guidelines for management

Benign enlargement of the prostate, also referred to as benign prostatic hyperplasia, is a common condition in men. Because enlarged prostate (EP) was viewed historically as a symptomatic condition, management of voiding symptoms with α-blockers was often the goal of therapy. However, it is now recognized that EP is a progressive disorder, which may be complicated by acute urinary retention and which may eventually require EP-related surgery. The 5α-reductase inhibitors decrease dihydrotestosterone levels, which slow disease progression by causing regression of the prostate epithelial cells. These agents are considered disease modifying, and they may reduce the progression of prostate enlargement. This article reviews evaluation, diagnosis, and treatment strategies for EP, and it provides a practical algorithm for management of patients with EP.

Dutasteride significantly improves quality of life measures in patients with enlarged prostate

The purpose of this study was to determine the effect of dutasteride on quality of life of men with lower urinary tract symptoms associated with enlarged prostate or benign prostatic hyperplasia (BPH) as measured by symptom problem index (SPI), BPH-specific interference with activities (BSIA), BPH-specific psychological well-being (BPWB) and BPH-specific lifestyle adaptations (BSLA). Data were derived from three randomized, double-blind studies conducted in 4325 men treated with placebo or dutasteride (0.5 mg/day). Primary analyses included changes from baseline in mean SPI, BSIA, BPWB and BSLA scores. Men treated with dutasteride showed significant improvements in SPI, BSIA, BPWB and BSLA scores compared with placebo.

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?

Method for evaluating prediction models that apply the results of randomized trials to individual patients

INTRODUCTION

The clinical significance of a treatment effect demonstrated in a randomized trial is typically assessed by reference to differences in event rates at the group level. An alternative is to make individualized predictions for each patient based on a prediction model. This approach is growing in popularity, particularly for cancer. Despite its intuitive advantages, it remains plausible that some prediction models may do more harm than good. Here we present a novel method for determining whether predictions from a model should be used to apply the results of a randomized trial to individual patients, as opposed to using group level results.

METHODS

We propose applying the prediction model to a data set from a randomized trial and examining the results of patients for whom the treatment arm recommended by a prediction model is congruent with allocation. These results are compared with the strategy of treating all patients through use of a net benefit function that incorporates both the number of patients treated and the outcome. We examined models developed using data sets regarding adjuvant chemotherapy for colorectal cancer and Dutasteride for benign prostatic hypertrophy.

RESULTS

For adjuvant chemotherapy, we found that patients who would opt for chemotherapy even for small risk reductions, and, conversely, those who would require a very large risk reduction, would on average be harmed by using a prediction model; those with intermediate preferences would on average benefit by allowing such information to help their decision making. Use of prediction could, at worst, lead to the equivalent of an additional death or recurrence per 143 patients; at best it could lead to the equivalent of a reduction in the number of treatments of 25% without an increase in event rates. In the Dutasteride case, where the average benefit of treatment is more modest, there is a small benefit of prediction modelling, equivalent to a reduction of one event for every 100 patients given an individualized prediction.

CONCLUSION

The size of the benefit associated with appropriate clinical implementation of a good prediction model is sufficient to warrant development of further models. However, care is advised in the implementation of prediction modelling, especially for patients who would opt for treatment even if it was of relatively little benefit.

Hormonal interventions to prevent hormonal cancers: breast and prostate cancers

In 1998, the concept of breast cancer prevention became a reality with the approval of tamoxifen to reduce the risk of developing breast cancer in women at increased risk for the disease. This approval was based on decades of research on selective estrogen receptor modulators providing an understanding of the role of the estrogen receptor in breast cell growth, and an appreciation of the carcinogenic process. Although results from the Breast Cancer Prevention Trial demonstrated a 49% reduction in breast cancer in women at increased risk, there were associated toxicities related to the estrogenic effects of tamoxifen; that is, deep vein thrombosis, pulmonary embolism, and endometrial cancer. In an effort to improve its benefit-risk profile, tamoxifen is now being compared with raloxifene, a selective estrogen receptor modulator approved for the treatment and prevention of osteoporosis. This equivalency prevention Study of Tamoxifen and Raloxifene completed accrual of 19 747 high-risk postmenopausal women in November 2004. Meanwhile, another class of estrogen-directed drugs, the aromatase inhibitors, have shown efficacy in breast cancer adjuvant trials, spawning a number of prevention trials that have recently been initiated. As with breast cancer the hormonal contribution to prostate carcinogenesis was the basis for the Prostate Cancer Prevention Trial which showed that finasteride, an androgen antagonist, reduces the incidence of prostate cancer compared to placebo.

The Long-Term Outcome of Medical Therapy for BPH

OBJECTIVES

The lack of cure with medical therapy implies life-long treatment emphasising the need for a thorough understanding of the long-term outcome. We review the natural history, markers for progression, placebo effect, efficacy, pharmacoeconomic aspects, and preventive measures.

METHODS

Literature review with particular reference to long-term controlled studies using plant extracts, alpha1-blockers, 5alpha-reductase inhibitors (5-ARIs), and combination therapy.

RESULTS

There is a long-lasting (>or=12 mo) placebo response of symptoms (20% decrease) and maximum flow rate (10% rise). The five long-term controlled trials of plant extracts are inconclusive and therefore their role in contemporary medical management is still controversial. The alpha1-blockers provide fast amelioration of symptoms yet have no relevant impact on the risk of acute urinary retention or surgery. Combination therapy should be reserved for moderately or severely symptomatic patients with a high risk of progression; in the majority of patients the alpha1-blocker can be safely stopped after 6-12 mo. The preventive use of 5-ARIs in men with no or mild symptoms at risk of progression is scientifically sound yet not generally accepted mainly for economic reasons.

CONCLUSIONS

A sharp contrast exists between the duration of the longest controlled trial (4.5 yr) and the situation in real life with treatment periods up to one or two decades of life. Real-life and registry data will be the only source of this important information in the future.

Serum sex steroid hormones and lower urinary tract symptoms in Third National Health and Nutrition Examination Survey (NHANES III)

OBJECTIVES

To evaluate the association of circulating sex steroid hormones and sex hormone binding globulin (SHBG) with lower urinary tract symptoms (LUTS).

METHODS

We included 260 men, 60 years old or older, who participated in Phase 1 (1988 to 1991) of the Third National Health and Nutrition Examination Survey and for whom surplus serum was available. We measured the serum concentrations of testosterone, androstanediol glucuronide (AAG), estradiol, and SHBG. Free testosterone was calculated from the circulating testosterone, SHBG, and albumin. The cases (n = 128) were men with two to four symptoms (nocturia, hesitancy, incomplete emptying, and weak stream), but who had never undergone noncancer prostate surgery. The controls (n = 132) were men who neither had symptoms nor had undergone noncancer prostate surgery. We adjusted for age, race/ethnicity, waist circumference, cigarette smoking, alcohol consumption, and physical activity in logistic regression models and used sampling weights.

RESULTS

The cases had statistically significantly greater AAG and estradiol concentrations than did the controls. After multivariate adjustment, the men in the top tertile of AAG (odds ratio 2.62, 95% confidence interval 1.12 to 6.14) had a greater risk of LUTS compared with men in the bottom two tertiles. Also, men with a greater estradiol concentration (odds ratio 1.78, 95% confidence interval 0.91 to 3.49) and a greater estradiol/SHBG molar ratio (odds ratio 2.41, 95% confidence interval 1.39 to 4.17) had a greater risk of LUTS than did men with lower concentrations. No consistent associations were seen for circulating testosterone, free testosterone, or SHBG.

CONCLUSIONS

In this cross-sectional study representative of older U.S. men, circulating AAG, a metabolite of dihydrotestosterone, and estradiol were associated with an increased risk of having LUTS.

The effect of 5alpha-reductase inhibition with dutasteride and finasteride on semen parameters and serum hormones in healthy men

CONTEXT

Dutasteride and finasteride are 5alpha-reductase inhibitors (5ARIs) that dramatically reduce serum levels of dihydrotestosterone (DHT).

OBJECTIVE

Because androgens are essential for fertility, we sought to determine the impact of 5ARI administration on serum testosterone (T), DHT, and spermatogenesis. DESIGN, SETTING, SUBJECTS, AND INTERVENTION: We conducted a randomized, double-blinded, placebo-controlled trial in 99 healthy men randomly assigned to receive dutasteride (D; 0.5 mg) (n = 33), finasteride (F; 5 mg) (n = 34), or placebo (n = 32) once daily for 1 yr.

MAIN OUTCOME MEASURES

Blood and semen samples were collected at baseline and 26 and 52 wk of treatment and 24 wk after treatment and were assessed for T, DHT, and semen parameters.

RESULTS

D and F significantly (P < 0.001) suppressed serum DHT, compared with placebo (D, 94%; F, 73%) and transiently increased serum T. In both treatment groups, total sperm count, compared with baseline, was significantly decreased at 26 wk (D, -28.6%; F, -34.3%) but not at 52 wk (D, -24.9%; F, -16.2%) or the 24-wk follow-up (D, -23.3%; F, -6.2%). At 52 wk, semen volume was decreased (D, -29.7%; F, -14.5%, significantly for D) as was sperm concentration (D, -3.2%; [corrected] F, -7.4%, neither significant). There was a significant reduction of -6 to 12% in sperm motility during treatment with both D and F and at follow-up. Neither treatment had any effect on sperm morphology.

CONCLUSIONS

This study demonstrates that the decrease in DHT induced by 5ARIs is associated with mild decreases in semen parameters that appear reversible after discontinuation.

[Benign prostate hyperplasia: success and limitations of pharmacological therapy]

A profound knowledge of pathogenesis and natural history enables a differentiated therapy for elderly men with lower urinary tract symptoms due to benign prostatic hyperplasia (BPH). The role of phytotherapy is still controversially discussed and, therefore, not clearly recommended by any BPH-guideline. alpha(1)-blockers are the therapy of choice for symptomatic patients at a low risk of disease progression (prostate volume <30-40 ml). 5alpha-reductase inhibitors (5ARI) reduce the prostate volume by 20-25% and the risk for acute urinary retention/surgery by more than 50% compared to placebo. Combination therapy (alpha(1)-blocker plus 5ARI) is superior to either monotherapy, though this advantage is only demonstrable after a prolonged treatment period (>12 months).

Medical treatment of benign prostatic hyperplasia

Pharmaceutical preparations are commonly used for benign prostate hyperplasia. This article reviews the current understanding of the natural history of the condition and the literature regarding medical treatment.

Serum prostate-specific antigen as a predictor of prostate volume in Korean men with lower urinary tract symptoms

The aim of the study was to assess the utility of prostate-specific antigen (PSA) as a predictor of prostate volume indexes (total prostate volume (TPV), transition zone volume and transition zone index) in Korean men with lower urinary tract symptoms (LUTS). From September 2003 to April 2006, 3431 patients with LUTS were included in the study; they had a median age of 63.8 years, a median prostate volume of 22.6 ml and a median serum PSA of 1.04 ng/ml. Men with a baseline PSA of >10 ng/ml were excluded, to reduce the likelihood of including occult prostate cancer. Prostate volume indexes and serum PSA levels had an age-dependent log-linear relationship. Receiver operating characteristic curve analysis showed that PSA had good predictive value for various prostate volume indexes thresholds. The approximate age-specific criteria for detecting men with a TPV of >40 ml are PSA levels of 1.20, 1.44 and 1.72 ng/ml for men with LUTS in their sixth, seventh and eighth decades, respectively. The results show that serum PSA identifies Korean men with large prostates reasonably well. Korean men may produce and/or release more PSA per unit prostate volume than white men. The cutoffs for PSA and prostate volume to response to LUTS therapy should be determined in this population.

A review of the clinical efficacy and safety of 5α-reductase inhibitors for the enlarged prostate

BACKGROUND

Enlargement of the prostate is common among aging men, with an incidence of 90% by the age of 85 years. It is a progressive condition, with growth in prostate size accompanied by lower urinary tract symptoms that can result in long-term complications (eg, acute urinary retention [AUR], need for enlarged prostate-related surgery). Current pharmacologic treatment options include alpha-blockers (alfuzosin, doxazosin, tamsulosin, and terazosin) and 5alpha-reductase inhibitors (5ARIs) (finasteride and dutasteride).

OBJECTIVES

This article reviews the natural history of enlarged prostate and the data supporting management of this condition with alpha-blocker and 5ARI therapy, either as monotherapy or combination therapy, for symptomatic relief and a reduction in long-term disease progression.

METHODS

Pertinent English-language articles were identified through a search of MEDLINE (1966-week 2, May 2006) using such search terms as 5alpha-reductase inhibitor, alpha-blocker, benign prostatic hyperplasia, dutasteride, efficacy, enlarged prostate, finasteride, and safety.

RESULTS

Clinical trials of alpha-blockers in men with enlarged prostate have reported improvements in total symptom scores of 10% to 20% compared with placebo; however, these agents were not shown to reduce the risk of long-term complications or disease progression. Studies of the 5ARIs have reported significant reductions compared with placebo in the relative risk for AUR and enlarged prostate-related surgery, slowing of disease progression, and relief of symptoms. In studies of dutasteride, improvements in symptom scores were greater after 4 years of therapy compared with 2 years (-6.4 vs -4.3 points, respectively) and flow rates were better (2.6 vs 2.3 mL/sec). Six-year data for finasteride showed maintenance of the decreased risk for AUR and enlarged prostate-related surgery. Use of combination therapy with an alpha-blocker and a 5ARI may be of benefit in patients who require immediate relief of symptoms, with discontinuation of the alpha-blocker after several months of therapy. 5ARIs were generally well tolerated, with sexual dysfunction the most frequently reported adverse effect, although in only a small proportion of men (1%-8%).

CONCLUSIONS

The use of 5ARI therapy is a rational approach to symptom management and prevention of long-term negative outcomes in men with enlarged prostates.V 3.

The effect of dutasteride on intraprostatic dihydrotestosterone concentrations in men with benign prostatic hyperplasia

The dual 5alpha-reductase inhibitor, dutasteride has been shown to suppress serum dihydrotestosterone (DHT) by >90%. In the present study, the effect of dutasteride 0.5 mg/day on intraprostatic DHT levels was investigated. In this multicenter, double-blind trial, 43 men with benign prostatic hyperplasia (BPH) scheduled to undergo transurethral resection of the prostate (TURP) were randomized to receive dutasteride, 0.5 mg/day or placebo for 3 months before surgery. Intraprostatic DHT, testosterone and dutasteride levels were determined at the time of TURP. Changes in serum DHT and testosterone from baseline, and both serum and intraprostatic dutasteride levels at the time of TURP were also assessed. Dutasteride reduced intraprostatic DHT by 94% relative to placebo (P<0.001); the adjusted mean intraprostatic DHT concentration was 3.23 and 0.209 ng/g in the placebo and dutasteride groups, respectively. In the dutasteride group, serum DHT was reduced from baseline by 93% at month 3, a significantly greater reduction (P<0.001) than the 15% decrease observed in the placebo group. There was a reciprocal increase in intraprostatic testosterone but the level of intraprostatic testosterone in the dutasteride group tended to be lower than the intraprostatic DHT level in the placebo group (P=0.06). Significant intraprostatic DHT suppression was achieved in all subjects who received dutasteride, regardless of the level of intraprostatic dutasteride. There was a strong positive correlation between serum and intraprostatic dutasteride concentrations (R(2)=0.73). After 3 months of treatment, dutasteride 0.5 mg/day provided near-complete suppression of both intraprostatic and serum DHT in men with BPH.

Can effect of finasteride on prostate-specific antigen be used to decrease repeat prostate biopsy?

OBJECTIVES

Patients often undergo multiple prostate biopsies for persistently elevated prostate-specific antigen (PSA) levels. Finasteride decreases serum PSA by approximately 50%. We performed a pilot study to examine the correlation among finasteride, PSA, and PSA density (PSAD) to identify patients who could be excluded from repeat prostate biopsy.

METHODS

We performed a prospective study from 2001 to 2002 on 25 men with elevated PSA levels. These patients had prior negative prostate biopsy findings. At study onset, the patients' PSA level and PSAD were measured. Patients were instructed to take finasteride 5 mg for 6 months. PSA and PSAD determination and prostate biopsies were repeated at 6 months and the findings compared with the initial results.

RESULTS

The mean patient age was 67.2 years (median 62). The median PSA level was 8.3 ng/dL at study entry (mean 9.34) and 4.6 ng/dL (mean 5.09) at 6 months. The median PSAD was 0.18 (mean 0.20) at study entry and 0.09 (mean 0.12) at 6 months. Of the 23 patients who completed the study, 6 (26%) were diagnosed with prostate cancer. At study entry, the median PSA level in those with prostate cancer was 9.6 ng/dL and was 5.8 ng/dL at 6 months. Patients without prostate cancer on repeat biopsy had a 44% decrease in PSAD. Patients with prostate cancer had a 5% decrease in PSAD.

CONCLUSIONS

The results of our study have demonstrated that patients without prostate cancer have a greater decrease in PSAD when taking finasteride than those with prostate cancer. This pilot study had a small population with limited power, and a repeat prospective study with a larger population is warranted.

Managing enlarged prostate in primary care

Assessment and treatment of benign prostatic hyperplasia, or enlarged prostate, has evolved considerably in recent years; clear evidence has accumulated for the progression of disease over time, the association between disease progression and negative outcomes, and the potential for medical management of this condition. Commensurate with the long-term preventive role of primary care, efforts can and should be made to treat the underlying condition of enlarged prostate as well as to manage the symptoms short-term. This review outlines evaluation of men presenting with lower urinary tract symptoms, examines the challenges for medical treatment and suggests how treatment choice can address these challenges.

Transcript profiling of the androgen signal in normal prostate, benign prostatic hyperplasia, and prostate cancer

Human prostate adenocarcinoma (CaP) and benign prostatic hyperplasia (BPH) have epithelial and stromal cell origins, respectively. To determine whether the androgen signal is processed differently in these cell types the expression of transcripts for enzymes that control ligand access to the androgen receptor (AR) were measured. Transcripts for type 2 5alpha-reductase, ketosteroid reductases [aldo-keto reductase (AKR)1C1-AKR1C4], the major oxidative 3alpha-hydroxysteroid dehydrogenase (HSD) retinol dehydrogenase (RODH)-like 3alpha-HSD (RL-HSD) and nuclear receptors [AR, estrogen receptor (ER)alpha, and ERbeta] were determined in whole human prostate and in cultures of primary epithelial cells (PEC) and primary stromal cells (PSC) from normal prostate, CaP and BPH by real-time RT-PCR. Normal PEC (n=14) had higher levels of AKR1C1 (10-fold, P<0.001), AKR1C2 (115-fold, P<0.001) and AKR1C3 (6-fold, P<0.001) than normal PSC (n=15), suggesting that reductive androgen metabolism occurs. By contrast, normal PSC had higher levels of AR (8-fold, P<0.001) and RL-HSD (21-fold, P<0.001) than normal PEC, suggesting that 3alpha-androstanediol is converted to 5alpha-dihydrotestosterone to activate AR. In CaP PEC (n=14), no significant changes in transcript levels vs. normal PEC were observed. In BPH PSC (n=21) transcripts for AR (2-fold, P<0.001), AKR1C1 (4-fold, P<0.001), AKR1C2 (10-fold P<0.001), AKR1C3 (4-fold, P<0.001) and RL-HSD (3-fold, P<0.003) were elevated to increase androgen response. Differences in the AR:ERbeta transcript ratios (eight in normal PEC vs. 280 in normal PSC) were maintained in PEC and PSC in diseased prostate. These data suggest that CaP may be more responsive to an ERbeta agonist and BPH may be more responsive to androgen ablation.

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.

Emerging drug therapies for benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is the nonmalignant enlargement of the prostate gland caused by increases in number of both epithelial and stromal cells. Clinically, BPH leads to voiding dysfunction, which is most often referred to as lower urinary tract symptoms (LUTS). Historically, the only treatments for LUTS due to BPH were watchful waiting or surgery (transurethral or open prostatectomy). However, over the last 20 years medical therapy has taken a prominent role in the management of BPH. Current medical treatments for BPH include alpha-adrenergic receptor antagonists, inhibitors of the 5-alpha reductase enzyme and various phytotherapies. These agents are generally effective and safe; however, many patients are unable to tolerate the side effects or are refractory to medical management and require surgery. In light of this, many potential new therapies for the treatment of BPH are under development. Some represent a variation of current treatments, whereas others target novel molecular pathways within the prostate. The aim of this review is to examine current pharmacotherapies as well as to highlight emerging drugs that may improve our treatment of patients with LUTS secondary to BPH.

Long-term results of medical treatment in benign prostatic hyperplasia

OBJECTIVES

In real-life clinical practice, we determined the incidence of acute urinary retention (AUR) and benign prostatic hyperplasia (BPH)-related surgery in patients with BPH who received alpha-adrenergic receptor blocker (alpha-blocker) and/or 5-alpha-reductase inhibitor combination treatment.

METHODS

This retrospective study enrolled 341 patients with BPH who were prescribed an alpha-blocker and/or a 5-alpha-reductase inhibitor as their first treatment from January 1997 to June 1999. Using follow-up data from a 6 to 8-year period, we calculated the incidence of AUR and BPH-related surgery in the alpha-blocker-only group and in the combination group.

RESULTS

Of the 341 patients, 192 were in the alpha-blocker group and 149 were in the combination group. Of these, 17.7% in the alpha-blocker group and 12.1% in the combination group experienced AUR (P <0.05). BPH-related surgery was performed in 10.9% of the alpha-blocker-only group and 6.0% of the combination group (P <0.05). The incidence of AUR and BPH-related surgery was reduced by 32.3% and 48.9% when the prostate volume was larger than 35 g and by 49.4% and 60.6% when the prostate-specific antigen level was greater than 2.0 ng/mL, respectively, in the combination group compared with the corresponding values in the alpha-blocker group.

CONCLUSIONS

Real-life clinical practice showed that long-term combination treatment with alpha-blockers and 5-alpha-reductase inhibitors reduced the risk of BPH progression, such as AUR or BPH-related surgery, compared with alpha-blocker-only treatment.

Interpreting Statistics in the Urological Literature

PURPOSE

Knowledge of statistical terminology and the ability to critically interpret research findings are critical skills in the practice of evidence based medicine.

MATERIALS AND METHODS

We provide a series of nontechnical explanations of basic statistical concepts commonly encountered in the urological literature. In addition, we provide examples of common statistical pitfalls to increase awareness of limitations to consider when applying research findings to practice.

RESULTS

Statistical goals encountered in the urological literature can be broadly categorized as summarizing outcome variables, comparing 2 or more groups, measuring association among variables or predicting 1 variable from another. Errors frequently include the use of an inappropriate test for the data type of interest or using statistical testing in a manner that increases the likelihood of false-positive results. Such errors pose a threat to the validity of research findings and they may undermine study conclusions.

CONCLUSIONS

Editors and reviewers alike should strive for high standards of statistical analysis and reporting, and promote the publication of high quality evidence in the urological literature. The understanding of basic statistical concepts and the principles of the hypothesis testing framework is essential to the critical appraisal process and, therefore, important to all urologists. Statistical literacy should be fostered through educational materials and courses in the urological community.

Evaluation of short term clinical effects and presumptive mechanism of botulinum toxin type A as a treatment modality of benign prostatic hyperplasia

The purpose of this study was to evaluate the effect and investigate the putative mechanism of botulinum toxin type A (BTA) applied to the treatment of benign prostatic hyperplasia (BPH). A total of 52 patients with symptomatic BPH were evaluated. Transperineal intraprostatic injection under transrectal ultrasonography was carried out. BTA dissolved in 4 to 9 mL of saline was used from 100 U to 300 U, according to prostate volume. Twenty-six patients received only BTA (BT group), and 26 received both BTA and one month of an alpha-adrenergic antagonist (BTalpha group). The therapeutic outcomes were evaluated by comparing parameters such as international prostate symptom score (IPSS), quality of life, prostate specific antigen, prostate volume, post-void residual urine, and peak urinary flow rate. At the one month follow- up, 18 patients in the BT group and 21 in the BTalpha group had subjective symptomatic relief (p = 0.337). Only IPSS5 (weak stream) was significantly different between the BT group and BTalpha groups (p = 0.034). At the three month follow-up, 39 patients had subjective symptomatic relief. The storage symptoms were improved more than the voiding symptoms. Additionally, about 50 percent of the patients whose voiding symptom improved expressed improved erectile function. BTA injection seems to be an alternative treatment for BPH. The differences after the one month evaluation between the BT and the BTalpha groups might suggest that the adrenergic influence could be relatively reinforced by the anticholinergic effect of BTA. Nitric oxide would thus be involved in a BTA action mechanism in BPH.

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.

Public, patient, and professional attitudes towards the diagnosis and treatment of enlarged prostate: A landmark national US survey

This US national survey evaluated beliefs and attitudes towards the enlarged prostate (EP) and its treatment among the men of a national sample aged > or =50 years in the US (400 with and 700 without EP), and a national sample of 100 primary care doctors and 100 urologists. The principal risk of EP was considered to be acute urinary retention among the majority of physicians, while the majority of patients believed it to be prostate cancer. In contrast to physicians' beliefs, the majority of patients with moderate-to-severe symptoms are more concerned with long-term effects of EP than acute symptoms. Furthermore, they are willing to wait up to 3 months for symptom relief if treatment of the underlying condition is achieved. Doctors and patients agree that most patients want to avoid surgery but only 18% of surgery patients were told about drugs that could reduce the risk of surgery. These findings demonstrate significant differences between the beliefs and attitudes of patients and physicians towards EP.

The interpretation of serum prostate specific antigen in men receiving 5alpha-reductase inhibitors: a review and clinical recommendations

PURPOSE

We reviewed the effects of 5alpha-reductase inhibitors on prostate specific antigen and clarified the adjustments that should be made to compensate for these effects to ensure that the usefulness of prostate specific antigen for detecting prostate cancer is maintained.

MATERIALS AND METHODS

We reviewed articles published in the scientific literature with relevance to the effects of 5alpha-reductase inhibitors on the usefulness of prostate specific antigen for detecting prostate cancer.

RESULTS

A total serum prostate specific antigen of 4.0 ng/ml has traditionally been used as the threshold for triggering prostate biopsy. However, clinical trials of finasteride and dutasteride have shown that 5alpha-reductase inhibitors decrease serum prostate specific antigen in patients with and without prostate cancer. To compensate, the doubling rule has been applied in clinical trials and clinical practice. However, doubling serum prostate specific antigen may overestimate actual prostate specific antigen in some patients receiving 5alpha-reductase inhibitors for up to 6 to 9 months, accurately estimate prostate specific antigen from 1 to 3 years and underestimate it thereafter. An increase in prostate specific antigen of 0.3 ng/ml from nadir as a trigger for biopsy maintains 71% sensitivity for prostate cancer in men receiving dutasteride with 60% specificity, similar to the 4.0 ng/ml prostate specific antigen cutoff using placebo.

CONCLUSIONS

We propose that a prostate specific antigen increase from nadir of 0.3 ng/ml or greater could represent an alternative to the doubling rule for monitoring prostate specific antigen in patients on 5alpha-reductase inhibitors. The prostate specific antigen increase from nadir appears to be a more accurate cancer indicator than a doubled value in some patients.

The economics of medical therapy for lower urinary tract symptoms associated with benign prostatic hyperplasia

Medical therapy is currently the most popular treatment choice for lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH). Because medical therapy of BPH-related LUTS is considered a life-long strategy, short- and long-term cost considerations should play a major role in therapeutic decision-making. The effectiveness in terms of long and short amelioration of symptoms, flow rate, and quality of life are well documented for 5alpha-blockers and 5alpha-reductase inhibitors as well as for the gold standard treatment for BPH, transurethral resection of the prostate and minimally invasive therapies. Short- and long-term safety concerns also are well documented for these various treatment options. On the contrary, short- and long-term costs have been less well studied and comparisons depend on the model or analyses undertaken in the few studies available. However, the economic studies based on prospective clinical trial data that have become available throughout the past several decades allow us to rationalize our use of alpha- blockers, 5alpha-reductase inhibitors, and combination therapy, taking into consideration age, severity of symptoms, prostate volume, prostate-specific antigen, and the differential response of the various medications (and combination) in selected patients. Based on current studies, 5alpha-blockers generally provide cost-effective therapy for most patients, whereas 5alpha-reductase therapy and combination therapy provide cost-effective treatment for patients with larger prostate glands or higher baseline prostate-specific antigen levels.

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.