Nonsteroidal antiandrogens: a therapeutic option for patients with advanced prostate cancer who wish to retain sexual interest and function

Phase II Study of Enzalutamide for Patients With Androgen Receptor-Positive Salivary Gland Cancers (Alliance A091404)

PURPOSE

The androgen receptor (AR) is expressed (+) in a subset of salivary gland cancers (SGCs). This phase II trial evaluated the efficacy of the antiandrogen enzalutamide in AR+ SGC.

METHODS

Patients with locally advanced/unresectable or metastatic AR+ SGCs were enrolled. Enzalutamide (160 mg) was given orally once daily. The primary end point was the best overall response rate per RECIST v1.1 within eight cycles. Confirmed responses in ≥ 5 of 41 patients would be considered promising. Secondary end points were progression-free survival, overall survival, and safety.

RESULTS

Forty-six patients were enrolled; 30 (65.2%) received prior systemic therapy, including 13 (28.3%) with AR-targeted drugs. Of seven (15.2%) partial responses (PRs), only two (4.3%) were confirmed per protocol and counted toward the primary end point. Twenty-four patients (52.2%) had stable disease; 15 (32.6%) had progression of disease as best response. Twenty-six patients (56.5%) experienced tumor regression in target lesions; 18 (39.1%) had partial response/stable disease ≥ 6 months. Tumor regressions were observed in female patients (5 of 6 [83.3%]) and those who received prior AR- (6 of 13 [46.2%]) or human epidermal growth factor receptor 2-targeted therapies (5 of 8 [62.5%]). Three patients remained on treatment at data cutoff (duration, 32.2-49.8 months). The median progression-free survival was 5.6 months (95% CI, 3.7 to 7.5); the median overall survival was 17.0 months (95% CI, 11.8 to 30.0). The most common adverse events were fatigue, hypertension, hot flashes, and weight loss. Total and free testosterone levels increased by a mean of 61.2% and 48.8%, respectively, after enzalutamide.

CONCLUSION

Enzalutamide demonstrated limited activity in AR+ SGC, failing to meet protocol-defined success in part because of a lack of response durability. Strategies to enhance the efficacy of antiandrogen therapy are needed.

Androgen Flare after LHRH Initiation Is the Side Effect That Makes Most of the Beneficial Effect When It Coincides with Radiation Therapy for Prostate Cancer

Simple Summary

Prostate cancer tumor growth is stimulated by androgens. Surgical castration or medical castration using long-acting luteinizing hormone-releasing hormone (LHRH) agonists or antagonists is the backbone of the treatments of metastatic disease. Treatment of locally advanced prostate cancer was accomplished with radiation therapy alone until multiple studies showed that combining radiation therapy with LHRH agonists results in significant survival benefit. While the goal of the use of LHRH agonists was to suppress testosterone levels during radiation, we show, through review of previous studies, that survival benefit was achieved only when LHRH was initiated during the course of radiation, and thus androgen flare during the first 1–3 weeks after the initiation of LHRH is most likely the reason for higher survival. Androgens drive tumor cells into mitosis, and mitotic death is the dominant mechanism of tumor cell kill by radiation.

Abstract

Treatment of metastatic prostate cancer was historically performed via bilateral orchiectomy to achieve castration. An alternative to surgical castration is the administration of subcutaneous recombinant luteinizing hormone-releasing hormone (LHRH). LHRH causes the pituitary gland to produce luteinizing hormone (LH), which results in synthesis and secretion of testosterone from the testicles. When LHRH levels are continuously high, the pituitary gland stops producing LH, which results in reduced testosterone production by the testicles. Long-acting formulations of LHRH were developed, and its use replaced surgical orchiectomy in the vast majority of patients. Combining LHRH and radiation therapy was shown to increase survival of prostate cancer patients with locally advanced disease. Here, we present a hypothesis, and preliminary evidence based on previous randomized controlled trials, that androgen surge during radiation, rather than its suppression, could be responsible for the enhanced prostate cancer cell kill during radiation. Starting LHRH agonist on the first day of radiation therapy, as in the EORTC 22863 study, should be the standard of care when treating locally advanced prostate cancer. We are developing formulations of short-acting LHRH agonists that induce androgen flare, without subsequent androgen deprivation, which could open the door for an era in which locally advanced prostate cancer could be cured while patients maintain potency.

Findings of Gynecomastia That Developed in Follow-up Secondary to Bicalutamide Treatment on Bone Scan

Prostate cancer is a common neoplastic disease especially in elder patients. Metastatic prostate disease has low five-year survival rate. Bicalutamide is an androgen receptor antagonist that acts as an inhibitor by competizing androgen receptors in the target tissue and used as a treatment option in prostate cancer. Bone scan was performed on a 79-year-old male with prostate cancer in our department. Blood pool images showed bilateral hyperemia in the breast regions which was not present on the previous scan one year ago. On physical examination, there was bilateral painful gynecomastia. It was learned that the patient was given Bicalutamide therapy after the first bone scan. Blood pool images may detect this side effect and should be evaluated with physical examination in case of clinical doubt.

Inhibition of RM-1 prostate carcinoma and eliciting robust immune responses in the mouse model by using VEGF-M2-GnRH3-hinge-MVP vaccine

GnRH and VEGF have been investigated as prostate carcinoma enhancers that support tumor spread and progression. Although both have documented roles in prostate carcinoma and many cancer types, the weak immunogenicity of these peptides has remained a major challenge for use in immunotherapy. Here, we describe a novel strategy to inhibit GnRH and VEGF production and assess the effect on the immune responses against these hormones using the RM-1 prostate cancer model. We designed a novel recombinant fusion protein which combined GnRH and VEGF as a vaccine against this tumor. The newly constructed fusion protein hVEGF121-M2-GnRH3-hinge-MVP contains the human vascular endothelial growth factor (hVEGF121) and three copies of GnRH in sequential linear alignment and T helper epitope MVP as an immunogenic vaccine. The effectiveness of the vaccine in eliciting an immune response and attenuating the prostate tumor growth was evaluated. Results showed that administration of a new vaccine effectively elicited humoral and cellular immune responses. We found that, a novel fusion protein, hVEGF121-M2-GnRH3-hinge-MVP, effectively inhibited growth of RM-1 prostate model and effectively promoted immune response. In conclusion, hVEGF121-M2-GnRH3-hinge-MVP is an effective dual mechanism tumor vaccine that limits RM-1 prostate growth. This vaccine may be a promising strategy for the treatment of hormone refractory prostate malignancies.

The impact of drugs on male fertility: a review

Beside cytotoxic drugs, other drugs can impact men's fertility through various mechanisms. Via the modification of the hypothalamic-pituitary-gonadal axis hormones or by non-hormonal mechanisms, drugs may directly and indirectly induce sexual dysfunction and spermatogenesis impairment and alteration of epididymal maturation. This systematic literature review summarizes existing data about the negative impact and associations of pharmacological treatments on male fertility (excluding cytotoxic drugs), with a view to making these data more readily available for medical staff. In most cases, these effects on spermatogenesis/sperm maturation/sexual function are reversible after the discontinuation of the drug. When a reprotoxic treatment cannot be stopped and/or when the impact on semen parameters/sperm DNA is potentially irreversible (Sulfasalazine Azathioprine, Mycophenolate mofetil and Methotrexate), the cryopreservation of spermatozoa before treatment must be proposed. Deleterious impacts on fertility of drugs with very good or good level of evidence (Testosterone, Sulfasalazine, Anabolic steroids, Cyproterone acetate, Opioids, Tramadol, GhRH analogues and Sartan) are developed.

PMH 9907: Long-term outcomes of a randomized phase 3 study of short-term bicalutamide hormone therapy and dose-escalated external-beam radiation therapy for localized prostate cancer

BACKGROUND

The role of hormone therapy (HT) with dose-escalated external-beam radiotherapy (DE-EBRT) in the treatment of intermediate-risk prostate cancer (IRPC) remains controversial. The authors report the long-term outcome of a phase 3 study of DE-EBRT with or without HT for patients with localized prostate cancer (LPC).

METHODS

From 1999 to 2006, 252 of an intended 338 patients with LPC were randomized to receive DE-EBRT with or without 5 months of neoadjuvant and concurrent bicalutamide 150 mg once daily. The study was closed early because of contemporary concerns surrounding bicalutamide. The primary outcome was biochemical failure (BF) incidence, and the secondary endpoints were overall survival (OS), local control (LC), and quality of life. The BF and OS rates were estimated using the cumulative incidence function and Kaplan-Meier methods and were compared using the Gray test and the log-rank test.

RESULTS

Eleven patients were excluded from analysis. Characteristics were well balanced in each treatment arm. Ninety-five percent of patients had IRPC. The prescribed dose increased from 75.6 grays (Gy) in 42 fractions to 78 Gy in 39 fractions over the period. At a median follow-up of 9.1 years, 98 BFs occurred, with no significant effect of HT versus no HT on the BF rate (40% vs 47%; P = .32), the OS rate (82% vs 86%; P = .37), the LC rate (52% vs 48 %; P = .32) or quality of life, in the patients who completed the questionnaires. Dose escalation to 75.6 Gy versus >75.6 Gy reduced the BF rate by 26% (P = .004).

CONCLUSIONS

For patients who predominantly have IRPC, the addition of HT to DE-EBRT did not significantly affect BF, OS, or LC. Bicalutamide appeared to be well tolerated. The conclusions from the study are limited by incomplete recruitment. Cancer 2016;122:2595-603. © 2016 American Cancer Society.

Long-term Efficacy and Safety of Enzalutamide Monotherapy in Hormone-naïve Prostate Cancer: 1- and 2-Year Open-label Follow-up Results

BACKGROUND

Enzalutamide is an androgen receptor inhibitor with a demonstrated overall survival benefit in metastatic castration-resistant prostate cancer. A phase 2 study of enzalutamide monotherapy in patients with hormone-naïve prostate cancer (HNPC) showed a high response rate for the prespecified primary endpoint (ie, prostate-specific antigen [PSA] response at week 25), regardless of metastases at baseline, and favorable tolerability.

OBJECTIVE

To determine the long-term efficacy and safety of enzalutamide monotherapy at 1 and 2 yr.

DESIGN, SETTING, AND PARTICIPANTS

Open-label, single-arm study in patients with HNPC and noncastrate testosterone (≥230 ng/dl).

INTERVENTION

Oral enzalutamide 160mg/d until disease progression or unacceptable toxicity.

OUTCOME MEASUREMENTS AND ANALYSIS

PSA response (≥80% decline from baseline) assessed at 1 yr (49 wk) and 2 yr (97 wk).

RESULTS AND LIMITATIONS

The median (range) age was 73 (48-86) yr and 26 patients (39%) presented with metastases at study entry. Of 67 patients enrolled, 45 (67%) remained on enzalutamide at week 97. For patients remaining on therapy, the PSA response rate at week 97 was 100% (95% confidence interval 92-100%). Of 26 patients with metastases at baseline, 13 (50%) had a complete and four (15.4%) had a partial response as best overall tumor response up to 97 wk on treatment. There was overall maintenance of total-body bone mineral density (BMD) and moderate changes in lean and fat body mass at 49 and 97 wk. The most common adverse events were gynecomastia, nipple pain, fatigue, and hot flushes. The study limitations include lack of a control group and of endocrine, glycemic, and lipid data at 97 wk.

CONCLUSIONS

Long-term enzalutamide monotherapy in men with noncastrate HNPC is associated with large sustained reductions in PSA, signals indicating a favorable tumor response, and favorable safety/tolerability profile, with relatively small negative effects on total-body BMD.

PATIENT SUMMARY

In this long-term follow-up of the efficacy and safety of enzalutamide monotherapy in patients with hormone-naïve prostate cancer, enzalutamide maintained long-term reductions in prostate-specific antigen, with a minimal impact on total-body bone mineral density.

TRIAL REGISTRATION

NCT01302041.

Identification of a group of brominated flame retardants as novel androgen receptor antagonists and potential neuronal and endocrine disrupters

Brominated flame-retardants (BFRs) are used in industrial products to reduce the risk of fire. However, their continuous release into the environment is a concern as they are often persistent, bioaccumulating and toxic. Information on the impact these compounds have on human health and wildlife is limited and only a few of them have been identified to disrupt hormone receptor functions. In the present study we used in silico modeling to determine the interactions of selected BFRs with the human androgen receptor (AR). Three compounds were found to dock into the ligand-binding domain of the human AR and these were further tested using in vitro analysis. Allyl 2,4,6-tribromophenyl ether (ATE), 2-bromoallyl 2,4,6-tribromophenyl ether (BATE) and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE) were observed to act as AR antagonists. These BFRs have recently been detected in the environment, in house dust and in aquatic animals. The compounds have been detected at high concentrations in both blubber and brain of seals and we therefore also assessed their impact on the expression of L-type amino acid transporter system (LAT) genes, that are needed for amino acid uptake across the blood-brain barrier, as disruption of LAT gene function has been implicated in several brain disorders. The three BFRs down-regulated the expression of AR target genes that encode for prostate specific antigen (PSA), 5α-reductases and β-microseminoprotein. The potency of PSA inhibition was of the same magnitude as the common prostate cancer drugs, demonstrating that these compounds are strong AR antagonists. Western blot analysis of AR protein showed that ATE, BATE and DPTE decreased the 5α-dihydrotestosterone-induced AR protein levels, further confirming that these BFRs act as AR antagonists. The transcription of the LAT genes was altered by the three BFRs, indicating an effect on amino-acid uptake across cellular membranes and blood-brain barrier. This study demonstrated that ATE, BATE and DPTE are potent AR antagonists and the alterations in LAT gene transcription suggest that these compounds can affect neuronal functions and should be considered as potential neurotoxic and endocrine disrupting compounds.

Tamoxifen for the management of breast events induced by non-steroidal antiandrogens in patients with prostate cancer: a systematic review

BACKGROUND

Tamoxifen has emerged as a potential management option for gynecomastia and breast pain due to non-steroidal antiandrogens, and it is considered an alternative to surgery or radiotherapy. The objective of this systematic review was to assess the benefits and harms of tamoxifen, in comparison to other treatment options, for either the prophylaxis or treatment of breast events induced by non-steroidal antiandrogens in prostate cancer patients.

METHODS

We searched CENTRAL, MEDLINE, EMBASE, reference lists, the abstracts of three major conferences and three trial registers to identify ongoing randomized controlled trials (RCTs). Two authors independently screened the articles identified, assessed the trial quality and extracted data. The protocol was prospectively registered (CRD42011001320; http://www.crd.york.ac.uk/PROSPERO).

RESULTS

Four studies were identified. Tamoxifen significantly reduced the risk of suffering from gynecomastia (risk ratio 9RR0 0.10, 95% CI 0.05 to 0.22) or breast pain (RR 0.06, 95% CI 0.02 to 0.17) at six months compared to untreated controls. Tamoxifen also showed a significant benefit for the prevention of gynecomastia (RR 0.22, 95% CI 0.08 to 0.58) and breast pain (RR 0.25, 95% CI 0.10 to 0.64) when compared to anastrozole after a median of 12 months. One study showed a significant benefit of tamoxifen for the prevention of gynecomastia (RR 0.24, 95% CI 0.09 to 0.65) and breast pain (RR 0.20, 95% CI 0.06 to 0.65) when compared with radiotherapy at six months. Radiotherapy increased the risk of suffering from nipple erythema and skin irritation, but there were no significant differences for any other adverse events (all P>0.05).

CONCLUSIONS

The currently available evidence suggests good efficacy of tamoxifen for the prevention and treatment of breast events induced by non-steroidal antiandrogens. The impact of tamoxifen therapy on long-term adverse events, disease progression and survival remains unclear. Further large, well-designed RCTs, including long-term follow-ups, are warranted. Also, the optimal dose needs to be clarified.

Novel, potent anti-androgens of therapeutic potential: recent advances and promising developments

The beneficial effect of androgen ablation has been well established in prostate cancer therapy. Despite the initial response, patients typically relapse with a more aggressive form described as castration-resistant prostate cancer (CRCP), driven by continued androgen receptor (AR) signaling. This review details the current state of anti-androgen therapy, mainly for CRPC, with major emphasis on the most potent and promising compounds under development. Anti-androgen failure has been linked to elevated AR expression, increased expression of coactivator proteins, AR mutations, ligand-independent AR activation and persistent intraprostatic androgens. MDV3100, BMS-641988 and VN/124-1 were developed to overcome these mechanisms. In CRCP, prostate cancer cells still rely on intracellular androgens and, to a greater extent, on active AR for growth and survival. Therefore, potent anti-androgens that efficiently disrupt the functions (signaling) of AR are envisioned to be effective drugs for all types of prostate cancers.

Hormonal therapy of prostate cancer

Of all cancers, prostate cancer is the most sensitive to hormones: it is thus very important to take advantage of this unique property and to always use optimal androgen blockade when hormone therapy is the appropriate treatment. A fundamental observation is that the serum testosterone concentration only reflects the amount of testosterone of testicular origin which is released in the blood from which it reaches all tissues. Recent data show, however, that an approximately equal amount of testosterone is made from dehydroepiandrosterone (DHEA) directly in the peripheral tissues, including the prostate, and does not appear in the blood. Consequently, after castration, the 95-97% fall in serum testosterone does not reflect the 40-50% testosterone (testo) and dihydrotestosterone (DHT) made locally in the prostate from DHEA of adrenal origin. In fact, while elimination of testicular androgens by castration alone has never been shown to prolong life in metastatic prostate cancer, combination of castration (surgical or medical with a gonadotropin-releasing hormone (GnRH) agonist) with a pure anti-androgen has been the first treatment shown to prolong life. Most importantly, when applied at the localized stage, the same combined androgen blockade (CAB) can provide long-term control or cure of the disease in more than 90% of cases. Obviously, since prostate cancer usually grows and metastasizes without signs or symptoms, screening with prostate-specific antigen (PSA) is absolutely needed to diagnose prostate cancer at an 'early' stage before metastasis occurs and the cancer becomes non-curable. While the role of androgens was believed to have become non-significant in cancer progressing under any form of androgen blockade, recent data have shown increased expression of the androgen receptor (AR) in treatment-resistant disease with a benefit of further androgen blockade. Since the available anti-androgens have low affinity for AR and cannot block androgen action completely, especially in the presence of increased AR levels, it becomes important to discover more potent and purely antagonistic blockers of AR. The data obtained with compounds under development are promising. While waiting for this (these) new anti-androgen(s), combined treatment with castration and a pure anti-androgen (bicalutamide, flutamide or nilutamide) is the only available and the best scientifically based means of treating prostate cancer by hormone therapy at any stage of the disease with the optimal chance of success and even cure in localized disease.

Six-month depot formulation of leuprorelin acetate in the treatment of prostate cancer

Hormonal deprivation therapy is well established for the treatment of locally advanced and metastatic prostate cancer, as well as the adjuvant treatment of some patients with localized disease. Long-acting gonadotropin releasing hormone (GnRH) agonists have become a mainstay of androgen deprivation therapy, due to their efficacy, tolerability, and convenience of use. One-month, 3-month, and 4-month depot leuprorelin formulations are well established and widely used to this end. Recently, a 6-month depot leuprorelin has been approved for use in advanced and metastatic prostate cancer patients. With similar efficacy and side effect profiles to earlier formulations, 6-month depot leuprorelin is a convenient treatment option for these patients. This review will highlight the role of GnRH agonists in the treatment of prostate cancer with a focus on the clinical efficacy, pharmacology, and patient-focused outcomes of the newer 6-month 45 mg depot leuprorelin formulation in comparison to available shorter-acting products.

Androgen deprivation therapy for prostate cancer

Androgen deprivation continues to play a crucial role in the treatment of advanced and metastatic prostate cancer. In the 65 years since its use was first described, urologists and medical oncologists have developed new and innovative ways to manipulate the hypothalamic-pituitary-gonadal axis with the goal of alleviating symptoms and prolonging the life of men with prostate cancer. Despite the successes that androgen deprivation therapy has brought, each method and regimen possesses unique benefits and burdens, of which the clinician and patient must be cognizant. This review discusses the first-line androgen deprivation methods and regimens presently in use with special attention paid to their side effects and the management of them, as well as the question of when to initiate androgen deprivation therapy.

Leuprorelin depot injection: patient considerations in the management of prostatic cancer

Hormone therapy is well established for treating patients with prostate cancer and remains the mainstay of the treatment of metastatic and locally advanced disease, this article reviews the rationale for its use, its different forms, and complications and controversies still surrounding some of its modalities. Availability of long-acting synthetic luteinizing hormone-releasing hormone (LHRH) agonists revolutionized the hormonal treatment of prostate cancer, and helped to avoid the emotional and psychological effects related to surgical castration. The depot formula has gained wide acceptance from both patients and physicians. This review emphasizes the newer, long-acting formula, leuprorelin (leuprolide acetate), especially the 6-month formula, its advantage over over shorter-acting depot products, and its potential to become a standard of care for patients eligible for androgen deprivation therapy.

Interventions for sexual dysfunction following treatments for cancer

BACKGROUND

The proportion of people living with and surviving cancer is growing. This has led to increased awareness of the importance of quality of life including sexual function in people with cancer. Sexual dysfunction (SD) is a potential long-term complication of cancer treatments.

OBJECTIVES

Evaluate effectiveness of interventions for SD following treatments for cancer and their adverse effects.

SEARCH STRATEGY

The Cochrane Pain, Palliative & Supportive Care Register, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, PsycInfo, AMED, CINAHL, Dissertation Abstracts and NHS Research Register were searched.

SELECTION CRITERIA

Randomised controlled trials (RCTs) were included that assessed the effectiveness of a treatment for SD. The trial population comprised of adults of either sex who at trial entry had developed SD as a consequence of cancer treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted the data and assessed trial quality. Meta-analysis was considered for trials with comparable key characteristics.

MAIN RESULTS

Eleven RCTs with a total of 1743 participants were identified. The quality of the trials was poor. Ten trials explored interventions for SD in men following treatments for non-metastatic prostate cancer. One trial explored effectiveness in women of a lubricating vaginal cream following radiotherapy for cervical cancer. The strongest evidence (from four trials) was on oral phosphodiesterase type 5 (PDE5) inhibitors for erectile dysfunction (ED) following radiotherapy of the prostate or radical prostatectomy. The results using validated measures in all trials significantly favoured those in the PDE5 inhibitor group(s). The combined results of two trials indicated a significantly greater improvement in ED in the PDE5 inhibitor groups (odds ratio (OR) 10.09 95% confidence interval (CI) 6.20 to 16.43). Negative effects were few and usually mild to moderate headaches or flushing. One trial reported more clinically serious events including six events of tachycardia and six of chest pain. Following prostate cancer treatments there was some evidence that PDE5 inhibitors are more effective in combination with acetyl-L-carnitine and propionyl-L-carnitine and that sexual counselling improves self-administration of prostaglandin intra-cavernous injection for SD. There was some evidence following treatment for prostate cancer that transurethral alprostadil and vacuum constriction devices reduce SD, although in both trials negative effects were fairly common. There is some evidence that vaginal lubricating creams reduce SD.

AUTHORS' CONCLUSIONS

PDE5 inhibitors are an effective treatment for SD secondary to treatments for prostate cancer. Other interventions identified need to be tested in further RCTs. The SD interventions in this review are not representative of the range available for men and women. Further evaluations are needed for these interventions for SD following cancer treatments.

What implications do the tolerability profiles of antiandrogens and other commonly used prostate cancer treatments have on patient care?

PURPOSE

Increased awareness of prostate cancer has led to earlier initiation of therapy, and the potential for a longer duration of treatment has led to a stronger emphasis on tolerability. Historically, the mainstay of treatment of hormone-sensitive prostate cancer has been castration-based therapy, but antiandrogens are now emerging as an alternative. This article reviews the tolerability profiles of antiandrogens as well as other existing treatments for prostate cancer and examines their implications on patient care.

METHODS

A search of online literature databases was conducted to identify recent articles and studies (1990-2006) that have reported adverse effects associated with treatment approaches for men with prostate cancer. The therapies reviewed here include castration, antiandrogens, a combination of castration and antiandrogens (CAB), estrogens, and chemotherapy.

RESULTS

Castration offers significant clinical benefits when used as monotherapy or as adjuvant therapy; however, it is associated with loss of bone mineral density, and a reduction in physical activity and sexual function, which can have a negative impact on quality of life. Detrimental effects on muscle mass, fat deposition, and cognitive function have also been reported. Recent data suggest that the non-steroidal antiandrogen, bicalutamide, confers a significant overall survival benefit when used as adjuvant to radiotherapy in patients with locally advanced disease. However, the survival data for bicalutamide are not as extensive as those available for LHRH agonists. Although they do not appear to have a significant impact on sexual and physical activity, non-steroidal antiandrogens are frequently associated with gynecomastia and breast pain, and some are associated with diarrhea. Estrogens have been used in patients with androgen-independent prostate cancer; however, cardiovascular toxicity has restricted their use. In patients whose prostate cancer has become hormone-refractory, treatment options include chemotherapeutic agents, such as docetaxel and mitoxantrone.

CONCLUSIONS

It is important for physicians to discuss the adverse effects of all the available treatment options with patients so that a therapy can be selected to meet their expectations in terms of overall survival and tolerability.

The addition of bicalutamide 150 mg to radiotherapy significantly improves overall survival in men with locally advanced prostate cancer

PURPOSE

Castration therapy adjuvant to radiotherapy can significantly improve overall survival compared with radiotherapy alone in patients with locally advanced prostate cancer. Although many of the adverse effects of castration therapy are manageable, they can have a detrimental effect on quality of life. Here we evaluate the efficacy and tolerability of the non-castration-based therapy bicalutamide ('Casodex') 150 mg adjuvant to radiotherapy in patients with T1-4, M0, any n prostate cancer.

METHODS

The subset of patients within the early prostate cancer (EPC) program who received radiotherapy with curative intent (n = 1,370) were included in the analysis. These patients were randomized to receive oral bicalutamide 150 mg once daily (n = 699) or placebo (n = 671).

RESULTS

The median follow-up for patients included in this analysis was 7.2 years. In patients with locally advanced disease (n = 305), bicalutamide adjuvant to radiotherapy significantly improved: progression-free survival (PFS), reducing the risk of objective progression by 44% compared with radiotherapy alone [hazard ratio (HR) 0.56; 95% confidence interval (CI) 0.40, 0.78; P < 0.001). Prostate-specific antigen (PSA)-PFS, reducing the risk of PSA progression by 59% compared with radiotherapy alone (HR 0.41; 95% CI 0.30, 0.55; P < 0.001). Overall survival, reducing the risk of death by 35% compared with radiotherapy alone (HR 0.65; 95% CI 0.44, 0.95; P = 0.03). This significant overall survival benefit for bicalutamide was driven by a lower risk of prostate cancer-related deaths (16.1 vs 24.3%, respectively). There was no significant difference in PFS or overall survival in patients with localized disease (n = 1,065).

CONCLUSIONS

In patients with locally advanced disease, bicalutamide 150 mg adjuvant to radiotherapy demonstrates significant clinical benefits in terms of overall survival, PFS and PSA-PFS compared with radiotherapy alone. The overall survival benefit in these patients is consistent with prior studies evaluating castration-based therapies adjuvant to radiotherapy (Bolla et al. in Lancet 360:103-108, 2002; Pilepich et al. in Int J Radiat Oncol Biol Phys 61:1285-1290, 2005). In addition, the clinical benefit of bicalutamide 150 mg in locally advanced patients, but not in those with localized disease, is consistent with the overall results from the EPC program (McLeod et al. BJU Int 97:247-254, 2006). Given the quality-of-life advantages of bicalutamide relative to castration, bicalutamide 150 mg adjuvant to radiotherapy is an attractive alternative for men with locally advanced prostate cancer.

Identification of a lead pharmacophore for the development of potent nuclear receptor modulators as anticancer and X syndrome disease therapeutic agents

A series of tetrahydroisoquinoline-N-phenylamide derivatives were designed, synthesized, and tested for their relative binding affinity and antagonistic activity against androgen receptor (AR). Compound 1b (relative binding affinity, RBA = 6.4) and 1h (RBA = 12.6) showed higher binding affinity than flutamide (RBA = 1), a potent AR antagonist. These two compounds also exerted optimal antagonistic activity against AR in reporter assays. The derivatives were also tested for their activities against another nuclear receptor, farnesoid x receptor (FXR), with most compounds acting as weak antagonists, however, compound 1h behaved as a FXR agonist with activity slightly less than that of chenodeoxycholic acid (CDCA), a natural FXR agonist.

Antiandrogen treatments in locally advanced prostate cancer: are they all the same?

PURPOSE

The objectives are to review the published literature and to evaluate the weight of evidence for clinical effectiveness, safety, and tolerability of the currently available antiandrogens in the treatment of locally advanced prostate cancer. This article covers efficacy as monotherapy relative to castration and as adjuvant to radiotherapy and radical prostatectomy as well as adverse-effect and quality-of-life data.

METHODS

The current literature from online databases between 1986 and the present, relating to antiandrogen treatments in men with locally advanced disease given either as monotherapy or as adjuvant to radical radiotherapy or prostatectomy, was reviewed. Antiandrogens researched included the non-steroidal antiandrogens, bicalutamide ('Casodex'), flutamide, and nilutamide, and the steroidal antiandrogen cyproterone acetate (CPA).

RESULTS

The most comprehensively investigated and reported antiandrogen is bicalutamide, which has shown survival outcomes similar to those observed with castration in patients with locally advanced prostate cancer. In contrast, only limited clinical data are available for the other non-steroidal antiandrogens (flutamide and nilutamide) and the steroidal antiandrogen CPA in patients with locally advanced disease. In terms of safety and tolerability, CPA is associated with loss of libido and erectile dysfunction. CPA is also associated with cardiovascular risk and there have been occasional reports of fatal fulminant hepatitis and hepatocellular carcinoma. Gynecomastia is quite rare with CPA, which is in contrast to the non-steroidal antiandrogens. There are no direct comparisons between the three non-steroidal antiandrogens in terms of quality of life, but available evidence suggests that bicalutamide has a more favorable safety and tolerability profile than nilutamide and flutamide. Unlike CPA, non-steroidal antiandrogens appear to be better tolerated than castration, allowing patients to maintain sexual activity, physical ability, and bone mineral density, but these agents have a higher incidence of gynecomastia and breast pain (mild to moderate in > 90% of cases). Gynecomastia and breast pain, however, can be effectively managed.

CONCLUSIONS

The available evidence indicates that the different antiandrogens should not be regarded as equivalents in clinical practice and so the choice of treatment for patients with prostate cancer should be made on an individual basis. It is, therefore, important for clinicians to discuss the efficacy and tolerability profiles of all available treatment options with their patients to enable them to choose a treatment program that best fits with their lifestyle.

Gynecomastia in patients with prostate cancer: update on treatment options

Non-steroidal antiandrogen monotherapy offers potential quality of life benefits over other treatment modalities in patients with prostate cancer. Nevertheless, gynecomastia and breast pain still represent the most bothersome side effects during this treatment. In this update article, recent advances in the management options for gynecomastia/breast pain caused by hormonal manipulation are reviewed and critically analyzed.

Management of gynaecomastia in patients with prostate cancer: a systematic review

Patients with prostate cancer are increasingly being offered treatment with non-steroidal antiandrogen monotherapy, which offers potential quality-of-life benefits compared with other treatment. Non-steroidal antiandrogens directly antagonise androgen action in breast tissue, and indirectly increase the oestrogen concentration. Thus, the most troublesome side-effects of monotherapy with these drugs are gynaecomastia and breast pain. Patients younger than 60 years of age, who might not have symptoms of prostate cancer, are probably more concerned about their body image and the development of enlarged breasts than are those older than 60 years. Clinicians who seek a treatment for prostate cancer need information on simple and well-tolerated options for the management of gynaecomastia and breast pain. In this review, management options for gynaecomastia caused by hormonal manipulation in patients with prostate cancer are discussed.

Flutamide administration at 500 mg daily has similar effects on serum testosterone to 750 mg daily

A prior comparison of 750 mg flutamide daily to 500 mg daily with an LHRH analog or orchiectomy showed no difference in effect on prostate specific antigen (PSA). However, any difference was likely masked by hypogonadism from concomitant LHRH analog or orchiectomy. We sought to evaluate different flutamide dosing schedules without this confounding factor. We recruited 50 men with advanced prostate cancer who elected to receive hormonal therapy to be randomized to 1 of 3 flutamide treatment groups: 1) 250 mg once daily, 2) 250 mg twice daily, or 3) 250 mg 3 times daily for 3 months, after which the therapy of their choice was instituted. Serum samples at the initiation of therapy and at the 1- and 3-month time point were assessed for PSA, testosterone, liver function tests, hematology, and renal function. Prostate volume, androgen deficiency symptoms, and a compliance diary were also recorded. Testosterone and PSA levels show a dose-dependent response to flutamide monotherapy. Loss of libido and erectile dysfunction occurred in all 3 treatment groups, with a trend toward worsening sexual function with higher flutamide dosing, but this trend did not reach statistical significance. Prostate volumes decreased by an average of 34.3% in the patients receiving 250 mg flutamide 3 times daily, 27.8% in patients receiving 250 mg flutamide twice daily, and 19.2% in those receiving a once daily dose of 250 mg flutamide. There was a significant difference between the once daily group and the 3 times daily group (P =.047). Flutamide at 500 mg did not result in significant changes in testosterone, PSA, prostate volume, or androgen deficiency symptoms compared to 750 mg daily after 3 months.

Gonadotropin-releasing hormone agonists in the treatment of prostate cancer

In 1979, the first prostate cancer patient was treated with a GnRH agonist at the Laval University Medical Center in Quebec City, Canada, thus rapidly leading to the worldwide replacement of surgical castration and high doses of estrogens. The discovery of medical castration with GnRH agonists was soon followed by fundamental changes in the endocrine therapy of prostate cancer. Most importantly, the excellent tolerance accompanying the treatment with GnRH agonists has been a key factor that permitted a series of studies demonstrating a major reduction in the death rate from prostate cancer ranging from 31 to 87% at 5 yr of follow-up in patients with localized or locally advanced prostate cancer. In fact, a one third reduction in prostate cancer deaths has been calculated in the metaanalysis of all available studies. The general acceptance of this discovery by patients and physicians is illustrated by world sales above 3.0 billion U.S. dollars in 2003. Although extremely efficient in achieving complete medical castration and well tolerated, with no other side effects than the expected hypoandrogenicity, GnRH agonists should not be administered alone. In fact, shortly after discovery of the castration effects of GnRH agonists, we observed that approximately 50% of androgens remain in the prostate after castration, thus leading to the recognition of the role of adrenal dehydroepiandrosterone as an important source of the androgens synthesized locally in the prostate and in many peripheral target tissues. We therefore developed combined androgen blockade (CAB), whereby the androgens of both testicular and adrenal origins are blocked simultaneously at start of treatment with the combination of a GnRH agonist to block the testis and a pure antiandrogen to block the action of the androgens produced locally. CAB, first used in advanced metastatic disease, has been the first treatment shown to prolong life in prostate cancer. Most interestingly, in 2002, we made the observation that CAB alone given continuously for 6.5 yr or more leads to cure of the disease in at least 90% of cases, thus suggesting that androgen blockade combining a GnRH agonist and a pure antiandrogen could well be the most efficient treatment of localized prostate cancer, and thus offering the possibility of practically eliminating death from prostate cancer.

Effects on Sexual Function by the Drugs used in the Treatment of Benign Prostatic Hyperplasia and Prostate Cancer. A Practical Guide for the Urologist

The effects on sexual function (SF) by the drugs commonly used in the treatment of benign prostatic hyperplasia (BPH) and prostate cancer (PC) have been analyzed. BPH therapy: alpha-blockers have no adverse effects on SF; the only one without significant hypotensive effect, Tamsulosin, can cause retrograde ejaculation in 4–8% of cases. 5-Alpha-reductase (Finasteride and Dutasteride) inhibitors could have detrimental effects on erectile function, libido and ejaculation in a small percentage of cases rarely exceeding 10%; these effects are reversible and their incidence reduces after 1 yr. Phytotherapy (extracts from pygeum africanum and serenoa repens) and mepartricin have no unfavorable action on SF. PC therapy: Loss of erectile function and libido are the norm with the use of LH-RH analogues, estrogens and steroidal antiandrogens (cyproterone acetate). Non-steroidal antiandrogens (Flutamide, Bicalutamide and Nilutamide) allow the preservation of SF in two-thirds of cases.

Épidémiologie et physiopathologie de la dysfonction érectile

Erectile dysfunction (ED) is a common condition with a significant deleterious effect on the quality of life. The prevalence rate of ED is about 20-45% and its incidence in western countries has been evaluated from 25 to 30 cases per 1000 person year. Risk factors of ED are ageing, diabetes, and cardiovascular, uro-genital, psychiatric and any chronic diseases. Smoking, hormonal factors and some drugs may be associated with ED. Modifications of risk factors must be initiated before the age of 50 to prevent ED occurrence. Two thirds of men with ED report embarrassment when discussing this problem with a physician and less than 25% ask for medical advice. As a symptom of endothelial dysfunction, ED may be considered a premonitory sign of coronary or peripheral vascular disease and diabetes.

BICALUTAMIDE 150 MG IN ADDITION TO STANDARD CARE IN PATIENTS WITH LOCALIZED OR LOCALLY ADVANCED PROSTATE CANCER: RESULTS FROM THE SECOND ANALYSIS OF THE EARLY PROSTATE CANCER PROGRAM AT MEDIAN FOLLOWUP OF 5.4 YEARS

PURPOSE

We evaluated the efficacy and tolerability of 150 mg bicalutamide daily given in addition to standard care, in patients with localized or locally advanced prostate cancer.

MATERIALS AND METHODS

The bicalutamide Early Prostate Cancer program consists of 3 randomized, double blind, placebo controlled trials prospectively designed for combined analysis. A total of 8,113 men with T1b-T4, M0, any N (N0 in 1 trial) prostate cancer were randomized to bicalutamide 150 mg/day (4,052) or placebo (4,061) in addition to standard care (radical prostatectomy, radiotherapy or watchful waiting). Primary end points were objective progression-free survival (PFS) and overall survival.

RESULTS

At median 5.4 years of followup (21.6% progression events) bicalutamide significantly improved PFS in the overall population. This result was driven by positive results in trials 24 and 25, with the North American trial (trial 23) showing no difference. Patients with locally advanced disease gained most benefit from bicalutamide in terms of PFS, irrespective of underlying therapy. Overall survival was similar in the bicalutamide and placebo groups, across the program and in each trial. Among watchful waiting patients survival appeared to be improved with bicalutamide in those with locally advanced disease, whereas survival appeared to be reduced with bicalutamide in those with localized disease. The most common adverse events with bicalutamide were gynecomastia and breast pain. Other adverse events occurred with a similarly low incidence in the 2 treatment groups.

CONCLUSIONS

This analysis confirms that bicalutamide provides benefit in patients with locally advanced disease. The current data suggest that early or adjuvant hormonal therapy for patients at low risk of disease progression, such as those with localized disease, is not appropriate.

An evaluation of bicalutamide in the treatment of prostate cancer

Although prostate cancer is traditionally considered a disease of old age, improved diagnostic techniques have resulted in early diagnosis, and many men are now treated while still physically and sexually active. Current therapies for prostate cancer often include medical or surgical castration, which cause adverse effects on physical and sexual function; therefore, greater attention has been focused on quality of life. The nonsteroidal antiandrogen bicalutamide is an effective agent with a favorable tolerability profile and, in some settings, represents an alternative to castration. Mature survival data reveal that bicalutamide monotherapy provides survival benefits for untreated locally advanced disease that do not differ significantly from those of castration and maintains better physical capacity and sexual interest. Recent data from a prospective randomized trial demonstrate that bicalutamide given as immediate therapy, either alone or as adjuvant to therapy of curative intent, significantly reduces the risk of objective disease progression in patients with localized or locally advanced prostate cancer. Antiandrogens are also used in combination with castration, a treatment known as combined androgen blockade (CAB), for advanced disease. A randomized trial demonstrated that CAB with bicalutamide is associated with similar survival outcome to CAB with flutamide and is better tolerated. Current evidence demonstrates that bicalutamide currently has a favorable risk-benefit ratio in several stages of prostate cancer and that the role of bicalutamide will be further defined by ongoing studies.

Clinical strategies in the management of biochemical recurrence after radical prostatectomy

Prostate cancer is the most frequently diagnosed cancer and the second leading cause of cancer death in men, following lung cancer. Although radical prostatectomy continues to be a curative treatment for most patients diagnosed with prostate cancer, nearly 25% of patients undergoing radical prostatectomy will have biochemical recurrence as defined by an increase in serum prostate-specific antigen (PSA) level to >0.4 ng/mL after prostatectomy or a rapid doubling of the PSA over a 10-year follow-up period. The clinical challenges, an overview of available data, and a framework for the integration of this information for clinical management of biochemical recurrence postprostatectomy for prostate carcinoma are presented in this article. Therapeutic options, in addition to conservative management and watchful waiting, include radiation therapy and androgen deprivation. These options are discussed herein along with expected outcomes.

Characteristics of primary nocturnal enuresis in adults: an epidemiological study

OBJECTIVE

To evaluate the prevalence and characteristics of primary nocturnal enuresis (PNE) in adults in Hong Kong, as there are currently limited epidemiological data in adults.

SUBJECTS AND METHODS

After a telephone survey, 8534 respondents (3996 males and 4538 females) aged 16-40 years were selected for the study and stratified in age groups. The questionnaire used comprised two parts; the first started with questions mainly about the general demographic background to decrease the sensitivity of the study and to establish rapport. The second part was conducted through an automated telephone interview service, with the questions being asked by recorded messages and the respondents then keying in their responses with no need to converse with an interviewer. This part included questions about enuretic symptoms and a subjective assessment of social and psychological effects of bedwetting, and measurements of the individual's self-esteem (Rosenberg Self-esteem Scale) and depression (The Centre for Epidemiological Studies Depression Scale).

RESULTS

Of the 8534 subjects interviewed, 196 had PNE, giving an overall prevalence of 2.3% (2.7% males and 2.0% females); of these 196, 36 (18.4%) also had daytime urinary incontinence. Hence, 1.9% of adults (2.2% males and 1.7% females) had monosymptomatic PNE. Of these, 53% wet >3 nights/week and 26% wet every night. Prevalence rates remained relatively stable among different age groups, with no apparent trend of a reduction with age. Compared with nonenuretic normal controls, significantly fewer enuretics reached tertiary education (33.4% vs 17.8%, P < 0.01). Bedwetters had a significantly higher incidence of depression and lower self-esteem, and a higher incidence of sleep disturbances than the control group. Among bedwetters, 32-40% felt that there was some effect on their choice of job, work performance and social activities, whilst 23% felt the condition affected their family life and in making friends of either sex. However, there was no significant difference in the marital status. Interestingly, only 34.5% of females and half of males used various methods before bedtime to prevent bedwetting.

CONCLUSIONS

Overall, 2.3% of Hong Kong adults aged 16-40 years have persistent PNE. Unlike PNE in early childhood the prevalence remained relatively unchanged with age, suggesting that enuretic symptoms persisting into adulthood are probably less likely to resolve with time. Also, significantly more patients had more severe enuretic symptoms. These findings therefore highlight the possibility that PNE in adults may represent a more pronounced form of the condition, and with a more serious social and psychological effect on affected individuals. Further work is needed to evaluate the pathogenesis and management strategy.

Bicalutamide monotherapy for early stage prostate cancer: an update

PURPOSE

The current evidence is considered to support 150 mg of the nonsteroidal antiandrogen bicalutamide for early stage prostate cancer.

MATERIALS AND METHODS

Data from phase III trials of 150 mg bicalutamide monotherapy for locally advanced disease are discussed. In addition, the first overall results are examined from the bicalutamide early prostate cancer program conducted at a median followup of 3 years, in which patients with localized or locally advanced disease were randomized to receive 150 mg bicalutamide or placebo as well as standard care.

RESULTS

Mature data from phase III studies have shown that 150 mg bicalutamide monotherapy provide similar survival outcome to that observed with castration in patients with locally advanced (M0) disease. Moreover, 150 mg bicalutamide have benefits over castration in terms of quality of life, particularly sexual interest and physical capacity, and preservation of bone mineral density. In the bicalutamide early prostate cancer program 150 mg significantly reduced the risk of objective progression in patients with localized or locally advanced disease at 3 years of median followup, with the greatest benefit seen in patients with poorer prognosis. Followup is ongoing to further determine the benefit of 150 mg bicalutamide in early prostate cancer.

CONCLUSIONS

Bicalutamide is emerging as a useful treatment option for early prostate cancer.

Early prostate cancer: prevention, treatment modalities, and quality of life issues

Our understanding of the screening, prevention and treatment of early prostate cancer is improving. This is a result of new data from clinical trials and the incorporation of efficacy measures based on risk assessment and quality of life (QoL). This review aims to examine completed and ongoing clinical trials that address issues in early prostate cancer, including screening, prevention, treatment, and QoL. Prostate-specific antigen (PSA) testing has a crucial and evolving role in detecting primary prostate cancer, evaluating prevention interventions and assessing the effectiveness of treatment. Questions remain about the optimal PSA parameters appropriate for primary screening and for diagnosing relapse. Emerging and established data provide evidence that early intervention with hormone therapy, either as immediate or adjuvant therapy, delays progression in prostate cancer patients with intermediate or poor prognosis. The impact of therapeutic modality on QoL has become better characterized, as QoL instruments have been developed, validated and applied.

The timing of hormone therapy for men with asymptomatic advanced prostate cancer

The most appropriate time to introduce hormonal therapy for patients with advanced prostate cancer is a contentious issue. Recent prospective studies comparing immediate and deferred hormonal therapy (medical or surgical castration) on survival outcome are reviewed with the aim of redefining the most appropriate time to initiate hormonal therapy for individual patients. The evidence supports the use of immediate hormonal therapy in previously untreated patients with advanced disease (M1) and also the use of adjuvant hormonal therapy after radical prostatectomy and lymphadenectomy for node-positive (but clinically localized) disease. Immediate hormonal therapy may also be advantageous in advanced local/regional disease when it is the primary treatment contemplated (i.e., without any definitive curative therapy to the prostate), although not all studies show this. Adjuvant hormonal therapy has significantly improved survival in some studies in the radiotherapy setting; the lack of statistically significant benefits in other studies may be a result of the timing of hormonal therapy in relation to the administration of external beam irradiation. Decisions on the immediate initiation of hormonal therapy should also take into account the patient's life expectancy and the side effects and long-term complications of androgen deprivation therapy. Recent epidemiological studies indicate that prostate cancer mortality has fallen in the USA. This decline in prostate cancer mortality is likely to be multifactorial with early application of hormonal therapy being one potential contributory factor. It is recommended that after an assessment of their disease risk, patients should be informed about the benefits and side effects of all potential treatment options and allowed to make an informed choice about their treatment.

Bicalutamide: in early-stage prostate cancer

Bicalutamide is an oral, once-daily nonsteroidal antiandrogen. Its efficacy in localised or locally advanced prostate cancer is currently being investigated as part of the Early Prostate Cancer (EPC) programme. In the EPC programme, bicalutamide 150 mg/day, as an adjunct to radiotherapy, radical prostatectomy or watchful waiting, significantly reduced the risk of objective disease progression, the incidence of bone metastases and the risk of prostate specific antigen progression compared with placebo (p < 0.0001 for all three parameters) after a median follow-up of 3 years. Survival data are currently immature, with an overall mortality rate of 6% in both treatment arms. On two nonblind, randomised trials, bicalutamide 150 mg/day monotherapy was as effective as medical or surgical castration in terms of overall survival in patients with locally advanced nonmetastatic prostate cancer. After a median follow-up of 6.3 years, median survival was 63.5 and 69.9 months for bicalutamide and castration, respectively; time to disease progression was also similar between treatment groups. Bicalutamide recipients reported a significantly smaller loss in sexual interest and a better physical capacity than recipients of castration (p <or= 0.05 for both parameters). Bicalutamide is well tolerated in studies of up to 6.3 years' duration.

The role of antiandrogen monotherapy in the treatment of prostate cancer

The mainstay of hormonal therapy in prostate cancer has been medical or surgical castration, both of which are associated with loss of libido and impotence, and may not always be acceptable to the patient. Antiandrogen monotherapy is an alternative treatment option to castration. There are two types of antiandrogen, i.e. steroidal (cyproterone acetate, CPA), and nonsteroidal (bicalutamide, flutamide and nilutamide). Data comparing survival outcome with CPA and castration are limited and conflicting. Furthermore, CPA is associated with loss of libido and erectile dysfunction. Large phase III trials have established that monotherapy with bicalutamide 150 mg once daily provides a survival outcome that is not significantly different to that after castration in men with locally advanced, non-metastatic disease, while conferring significant advantages for sexual interest and physical capacity. Current data are inadequate to draw conclusions on the comparative efficacy of flutamide and castration, while nilutamide is not licensed for monotherapy. Recent data reveal that bicalutamide 150 mg given once daily in addition to standard care (radical prostatectomy, radiotherapy or 'watchful waiting') significantly delays the progression of early (localized or locally advanced) prostate cancer. Bicalutamide has a more favourable side-effect profile than the other antiandrogens and is more likely to promote compliance.

Is there a role for antiandrogen monotherapy in patients with metastatic prostate cancer?

Castration is the most widely used form of androgen ablation employed in the treatment of metastatic (M1) prostate cancer. Non-steroidal antiandrogen monotherapy is a potential alternative treatment option for men for whom castration is unacceptable or not indicated. Of the three non-steroidal antiandrogens, bicalutamide ('Casodex'), flutamide and nilutamide, only bicalutamide has been compared with castration in large, controlled, randomised, Phase III trials in M1 patients. A post-hoc analysis of these studies indicated that bicalutamide 150 mg/day monotherapy may be of benefit to M1 patients with a prostate specific antigen (PSA) level </=400 ng/ml. Significant advantages for M1 patients treated with bicalutamide were observed in subjective response rate, maintenance of sexual interest and physical capacity. Patients with a higher disease burden (PSA >400 ng/ml) may decide that quality of life and symptomatic benefits outweigh the slight survival disadvantage seen in clinical trials and opt for bicalutamide monotherapy as an alternative to castration.Prostate Cancer and Prostatic Diseases (2001) 4, 196-203.

Antiandrogen monotherapy: indications and results

Many patients with prostate cancer for whom hormonal therapy is indicated are still physically and sexually active; quality of life is therefore a vital issue when considering treatment options. Traditional castration-based therapies, although effective, have implications with respect to quality of life, causing loss of libido, impotence, fatigue, and reduced bone mineral density. Monotherapy with a nonsteroidal antiandrogen is an attractive therapeutic alternative to castration, offering effective therapy with potential quality-of-life benefits. Of the available nonsteroidal antiandrogens, bicalutamide has been most extensively evaluated in the monotherapy setting. Mature combined data (56% mortality) from 2 large randomized studies show no statistically significant difference in overall survival between bicalutamide 150-mg monotherapy and castration in patients with locally advanced, nonmetastatic (stage M0) disease. Survival outcome in patients with metastatic (stage M1) disease (43% mortality) favored castration, although the difference in median survival between the groups was only 6 weeks. Bicalutamide 150-mg monotherapy was associated with significant advantages compared with castration, in terms of sexual interest and physical capacity, in patients with either M0 and M1 stage disease. Data from a small subgroup of patients with stage M0 disease suggest that bicalutamide may also reduce the risk of osteoporosis compared with castration. Long-term therapy with bicalutamide 150-mg monotherapy is generally well tolerated, with a predictable side-effect profile. The most common side effects are male breast pain and gynecomastia. Emerging evidence also supports the use of bicalutamide 150 mg, both as immediate monotherapy and as adjuvant therapy in early stage (localized or locally advanced) prostate cancer.

Emerging role of adjuvant hormonal therapy

Recent years have seen a downward shift in the most common disease stage at diagnosis and in the age of patients diagnosed with prostate cancer. Although younger men with clinically localized disease are generally offered radiotherapy or radical prostatectomy, such treatment does not always produce a cure. Adjuvant hormonal therapy (medical or surgical castration) has been shown to extend progression-free survival in both the radiotherapy and surgical settings, and overall survival benefits have also been demonstrated in some studies. However, castration is associated with sexual dysfunction that may be unacceptable, particularly among younger patients. The ongoing bicalutamide (Casodex; AstraZeneca Pharmaceuticals, Wilmington, DE) Early Prostate Cancer program is evaluating the efficacy and tolerability of bicalutamide 150 mg as immediate therapy, either alone or as an adjuvant to therapy of curative intent, in patients with localized or locally advanced prostate cancer. This is the largest clinical trial program in prostate cancer treatment to date, comprising 3 randomized, double-blind, placebo-controlled studies with a total of 8113 patients. At median follow-up period of 3 years and after 922 progression events, the bicalutamide group had a significant reduction of 42% in the risk of objective progression compared with patients who received placebo plus standard care. The risk of prostate-specific antigen progression was also significantly reduced by 59%. As expected, gynecomastia and breast pain were the most frequently reported side effects of bicalutamide therapy. A longer follow-up period will determine whether the reduced risk of progression will translate into cause-specific and overall survival benefit for these patients.