Endocrine effects, efficacy and tolerability of a 10.8-mg depot formulation of goserelin acetate administered every 13 weeks to patients with advanced prostate cancer

Testosterone analysis in prostate cancer patients

Testosterone is an essential steroid hormone associated with a wide variety of biological processes in humans. In prostate cancer, androgen signaling is an important driver of tumor cell growth. Depletion of gonadal testosterone, achieved by surgical or chemical castration, prevents androgenic signaling and temporally reduces, stops or reverses tumor growth before inevitable progression to castration-resistant prostate cancer occurs. Additional treatment strategies targeting androgenic signaling have become available, although these are without curative intent. While circulating testosterone is also associated with disease risk and potential clinical utility, the main use in the clinical lab is monitoring adequate castration and subsequent resistance to therapy. Adequate castrate testosterone concentrations are currently based on over 50 year-old double-isotope derivative assays that are disputed in automated immunoassay (IA) analysis. The debate has been further fueled with the introduction of mass spectrometry-based assays for testosterone, offering a substantial increase in sensitivity and specificity. In this review, we discuss testosterone regulation and androgen deprivation therapy in prostate cancer. We provide an overview of the developments in testosterone analysis for monitoring adequate castration and resistance to therapy. Current clinical practice and future clinical utility will be discussed. Finally, clinical and research recommendations will be presented.

Ovarian Function Suppression With Luteinizing Hormone-Releasing Hormone Agonists for the Treatment of Hormone Receptor-Positive Early Breast Cancer in Premenopausal Women

Chemotherapy and endocrine therapies are mainstays of treatment for early and advanced hormone receptor-positive (HR+) breast cancer. In premenopausal women with HR+ tumors, the benefits of adding ovarian function suppression (OFS) to endocrine therapy have been debated. Consequently, for many years, tamoxifen monotherapy has been the standard of care for endocrine treatment in the adjuvant setting. Recent studies have, however, provided new evidence that, in some premenopausal patients, OFS in combination with tamoxifen or aromatase inhibitors (AIs) can significantly increase survival versus tamoxifen alone. Luteinizing hormone-releasing hormone agonists (LHRHa), including goserelin, triptorelin, and leuprorelin, achieve OFS through sustained suppression of the release of follicle-stimulating hormone and luteinizing hormone from the pituitary. In turn, this suppresses production and secretion of estradiol, an ovarian hormone that supports cancer cell growth, survival, and proliferation. In this review, we discuss the clinical evidence supporting the addition of LHRHa to adjuvant endocrine therapies, including tamoxifen and AIs, for premenopausal women with breast cancer. We also discuss the role of LHRHa use in combination with adjuvant chemotherapy to preserve ovarian function and fertility in young patients with breast cancer. Finally, we discuss important practical aspects of the use of LHRHa in breast cancer treatment, including side-effects, patient adherence to treatment, and the use of slow-release, long-acting drug formulations.

Clinical strategies for optimizing infusion center care through a pandemic

The national pandemic resulting from the novel coronavirus, COVID-19, has made the delivery of care for patients with cancer a challenge. There are competing risks of mortality from cancer versus serious complications and higher risk of death from COVID-19 in immunocompromised hosts. Furthermore, compounding these concerns is the inadequate supply of personal protective equipment, decreased hospital capacity, and paucity of effective treatments or vaccines to date for COVID-19. Guidance measures and recommendations have been published by national organizations aiming to facilitate the delivery of care in a safe and effective manner, many of which, are permanently adoptable interventions. Given the critical importance to continue chemotherapy, there remains additional interventions to further enhance patient safety while conserving healthcare resources such as adjustments in medication administration, reduction in laboratory or drug monitoring, and home delivery of specialty infusions. In this manuscript, we outline how to implement these actionable interventions of chemotherapy and supportive care delivery to further enhance the current precautionary measures while maintaining safe and effective patient care. Coupled with current published standards, these strategies can help alleviate the numerous challenges associated with this pandemic.

Survivorship, Version 2.2017, NCCN Clinical Practice Guidelines in Oncology

Many cancer survivors experience menopausal symptoms, including female survivors taking aromatase inhibitors or with a history of oophorectomy or chemotherapy, and male survivors who received or are receiving androgen-ablative therapies. Sexual dysfunction is also common in cancer survivors. Sexual dysfunction and menopause-related symptoms can increase distress and have a significant negative impact on quality of life. This portion of the NCCN Guidelines for Survivorship provide recommendations for screening, evaluation, and treatment of sexual dysfunction and menopausal symptoms to help healthcare professionals who work with survivors of adult-onset cancer in the posttreatment period.

Androgen deprivation therapy complications

Androgen deprivation therapy (ADT) is increasingly used to treat advanced prostate cancer and is also utilised as adjuvant or neo-adjuvant treatment for high-risk disease. The resulting suppression of endogenous testosterone production has deleterious effects on quality of life, including hot flushes, reduced mood and cognition and diminished sexual function. Cross-sectional and longitudinal studies show that ADT has adverse bone and cardio-metabolic effects. The rate of bone loss is accelerated, increasing the risk of osteoporosis and subsequent fracture. Fat mass is increased and lean mass reduced, and adverse effects on lipid levels and insulin resistance are observed, the latter increasing the risk of developing type 2 diabetes. ADT also appears to increase the risk of incident cardiovascular events, although whether it increases cardiovascular mortality is not certain from the observational evidence published to date. Until high-quality evidence is available to guide management, it is reasonable to consider men undergoing ADT to be at a higher risk of psychosexual dysfunction, osteoporotic fracture, diabetes and cardiovascular disease, especially when treated for extended periods of time and therefore subjected to profound and prolonged hypoandrogenism. Health professionals caring for men undergoing treatment for prostate cancer should be aware of the potential risks of ADT and ensure appropriate monitoring and clinical management.

Androgen receptor antagonists for prostate cancer therapy

Androgen deprivation is the mainstay therapy for metastatic prostate cancer (PCa). Another way of suppressing androgen receptor (AR) signaling is via AR antagonists or antiandrogens. Despite being frequently prescribed in clinical practice, there is conflicting evidence concerning the role of AR antagonists in the management of PCa. In the castration-resistant settings of PCa, docetaxel has been the only treatment option for decades. With recent evidence that castration-resistant PCa is far from AR-independent, there has been an increasing interest in developing new AR antagonists. This review gives a concise overview of the clinically available antiandrogens and the experimental AR antagonists that tackle androgen action with a different approach.

Drug costs in the management of metastatic castration-resistant prostate cancer in Canada

BACKGROUND

For Canadian men, prostate cancer (PCa) is the most common cancer and the 3rd leading cause of cancer mortality. Men dying of PCa do so after failing castration. The management of metastatic castration-resistant prostate cancer (mCRPC) is complex and the associated drug treatments are increasingly costly. The objective of this study was to estimate the cost of drug treatments over the mCRPC period, in the context of the latest evidence-based approaches.

METHODS

Two Markov models with Monte-Carlo microsimulations were developed in order to simulate the management of the disease and to estimate the cost of drug treatments in mCRPC, as per Quebec's public healthcare system. The models include recently approved additional lines of treatment after or before docetaxel (i.e. abiraterone and cabazitaxel). Drug exposure and survival were based on clinical trial results and clinical practice guidelines found in a literature review. All costs were assigned in 2013 Canadian dollars ($). Only direct drug costs were estimated.

RESULTS

The mean cost of mCRPC drug treatments over an average period of 28.1 months was estimated at $48,428 per patient (95% Confidence Interval: $47,624 to $49,232). The mean cost increased to $104,071 (95% CI: $102,373 - $105,770) per patient when one includes abiraterone initiation prior to docetaxel therapy. Over the mCRPC period, luteinizing hormone-releasing hormone agonists (LHRHa) prescribed to maintain castrate testosterone levels accounted for 20.4% of the total medication cost, whereas denosumab prescribed to decrease bone-related events accounted for 30.5% of costs. When patients received cabazitaxel in sequence after abiraterone and docetaxel, the mCRPC medications cost per patient per month increased by 60.2%. The total cost of medications for the treatment of each annual Canadian cohort of 4,000 mCRPC patients was estimated at $ 193.6 million to $416.3 million.

CONCLUSIONS

Our study estimates the direct drug costs associated with mCRPC treatments in the Canadian healthcare system. Recently identified effective yet not approved therapies will become part of the spectrum of mCRPC treatments, and may potentially increase the cost.

'You know I've joined your club… I'm the hot flush boy': a qualitative exploration of hot flushes and night sweats in men undergoing androgen deprivation therapy for prostate cancer

OBJECTIVE

Hot flushes and night sweats are common amongst menopausal women, and psychological interventions for managing these symptoms have recently been developed for women. However, flushes in men with prostate cancer, which commonly occur following androgen deprivation therapy (ADT), remain under-researched. This study is a qualitative exploration of flush-related cognitive appraisals and behavioural reactions reported by a sample of these men.

METHODS

Semi-structured, in-depth interviews were conducted with 19 men who were experiencing flushes after receiving ADT for prostate cancer. Framework analysis was used to generate and categorise emergent themes and explore associations between themes.

RESULTS

Five main cognitive appraisals included the following: changes in oneself, impact on masculinity, embarrassment/social-evaluative concerns, perceived control and acceptance/adjustment. There were men who held beliefs about the impact of flushes on their perceptions of traditional gender roles, who experienced shame and embarrassment due to concerns about the salience of flushes and perceptions by others and who experienced feelings of powerlessness over flushes. Powerlessness was associated with beliefs about the potentially fatal consequences of discontinuing treatment. Two other dominant themes included awareness/knowledge about flushes and management strategies. Experiences of flushes appeared to be influenced by upbringing and general experiences of prostate cancer and ADT.

CONCLUSIONS

The range of men's appraisals of, and reactions to, flushes generated from this qualitative exploration were broadly similar to those of menopausal women but differed in terms of the influence of masculinity beliefs. These findings could be used to inform future research and psychological interventions in this under-researched field.

Leuprolide acetate 1-, 3- and 6-monthly depot formulations in androgen deprivation therapy for prostate cancer in nine European countries: evidence review and economic evaluation

Objective

Leuprolide is an established luteinizing hormone–releasing hormone (LHRH) agonist used as first-line treatment in advanced prostate cancer. As different formulations and dosing schedules are likely to have economic implications, we aimed to evaluate their efficacy, safety, and costs in nine European countries: Austria, Belgium, Czech Republic, Hungary, Italy, Latvia, Netherlands, Poland, and Portugal.

Methods

Database searches identified 13 clinical trials of leuprolide 1- (1 M), 3- (3 M) and 6-monthly (6 M). Only data on leuprolide with Atrigel were compared for all three formulations, which had the same efficacy, safety, and adherence. Cost-minimization analysis accounting for cost of Eligard®, specialist consultations, and diagnostics during up to 12 months follow-up was conducted. The perspective was that of public payers.

Results

No significant differences were observed in the percentages of intention-to-treat patients achieving testosterone levels ≤ 50 ng/dL following treatment with Eligard® 1 M (93.3%), 3 M (98.3%), and 6 M (97.3%) (P > 0.05), and adverse event profiles of the three formulations were comparable. Overall, 6 M was the least expensive, with average total annual costs from €788 (Belgium) to €1839 (Portugal). The 3 M option was between 2.5% (Hungary) and 37.6% (Belgium) more expensive than 6 M; 1 M formulation was the most expensive, with costs 15.5% and 151.6% more expensive than 6 M for those countries, respectively. The 3 M option was 11.2%–45.3% less expensive than 1 M. Total costs were associated with frequency of visits for injection and monitoring. The 1 M required twelve visits, 3 M 4.4–4.8 visits, and 6 M 2.1–2.3 visits. Up to 50% additional visits could be funded with the savings resulting from switching eligible patients from 1 M and 3 M to 6 M. Results were stable in univariate and probabilistic sensitivity analyses.

Conclusion

Eligard® formulations offer comparable efficacy and safety, but different dosing schedules require different number of visits. The 6 M formulation offers the greatest cost savings and should be considered the treatment of choice in eligible patients in Europe.

Serum testosterone levels after medical or surgical androgen deprivation: a comprehensive review of the literature

Androgens and the androgen receptor play a role in the progression of prostate cancer. Androgen deprivation therapy (ADT) is a mainstay in the treatment of metastatic prostate cancer. ADT is expected to reduce serum testosterone levels from a normal level of about 500 to 600 ng/dl (17.3-20.8 nmol) down to castration levels. Traditionally, castration was considered to be achieved if testosterone levels were lowered to a threshold of 50 ng/dl (1.73 nmol/l), a definition determined more by measurement methods derived from the use of old assay methods than by evidence. Serum testosterone levels in three-quarter patients after surgical castration drop to less than 20 ng/dl (0.69 nmol/l). Ineffective suppression of testosterone is currently poorly recognized and may possibly have an effect of prostate cancer mortality. Persistent levels of serum testosterone after castration are mainly derived from adrenal androgens. Furthermore, the arrival of new therapies targeting androgen synthesis and androgen receptor activity has renewed interest on serum testosterone. This review discusses the biosynthetic pathway for androgen synthesis in humans and provides a comprehensive review of serum testosterone levels after surgical or medical castration. This review assesses serum testosterone levels after surgical castration and different pharmacologic castration in patients with prostate cancer under ADT, and ineffective testosterone suppression. The author proposes methods to better lower serum testosterone levels during ADT.

[Change of the LHRH analogue in progressive castration-refractory prostate cancer]

INTRODUCTION

Medicinal or surgical castration remains the treatment of choice in metastatic, hormone-naive prostate cancer; however, 2-12% of patients never reach the target serum levels for medicinal castration. We analyzed the therapeutic efficacy of triptorelin pamoate (TP) as salvage treatment due to its higher potency than endogenous luteinizing hormone-releasing hormone (LHRH). The amino acid sequence of TP is identical to that of endogenous LHRH except for position 6 where L-glycine is replaced by D-tryptophane rendering the synthetic moiety less susceptible to cleavage by proteolytic enzymes.

PATIENTS AND METHODS

In this study 36 patients with prostate-specific antigen (PSA) progression following first line complete androgen blockade and antiandrogen (ADT) withdrawal were retrospectively analyzed. All patients demonstrated no or minimal metastatic disease. The PSA levels, PSA doubling time (PSADT), PSA velocity (PSAV) and testosterone serum concentrations were correlated with the therapeutic response. All patients received TP at a dose of 11.5 mg at 3-month intervals until documented progression.

RESULTS

The mean patient age was 69.2 years (range 52-79 years), the mean PSA level was 23.4 ng/ml (8.7-53.1 ng/ml) and the mean PSADT was 9.2 months (2.9-15.4 months). Mean testosterone serum concentration was 38.67 ng/dl (21-76 ng/dl), the mean time between start of ADT and progression was 42.4 months (13-76 months) and the median time was 46.8 months (16-82 months). A PSA decrease of ≥50% was reached in 9 out of 36 (25%) patients, 3 out of 36 (13.9%) patients each demonstrated stable PSA levels and a prolongation of PSADT from 6.2 to 9.8 months. Mean progression-free survival (PFS) was 21.4 weeks (7-53 weeks). PSA-responders exhibited a PFS of 53.2 weeks (26-64 weeks) as compared to 28 weeks (17-35 weeks) in nonresponders. PSA responders demonstrated significantly higher testosterone serum concentrations of 48.3 ng/dl (29-76 ng/dl) as compared to nonresponders with 32.6 ng/dl (21-62 ng/dl, p=0.02). Mean follow-up was 31.4 months (27-39 months), overall survival was 80.5% and cancer-specific survival was 88.9%.

CONCLUSION

Changing the LHRH analogue in castration-refractory prostate cancer (CRPC) with testosterone serum concentrations at or above the castration level results in a temporary PSA response. This treatment option might be included in the therapeutic algorithm of CRPC. Although the PFS is short it allows the continuation of a treatment option with minimal side effects in a mere palliative situation. The data underline the need for continuous monitoring of testosterone during treatment with LHRH analogues.

Risk stratification in the hormonal treatment of patients with prostate cancer

Prostate cancer (PCa) is the most common type of cancer found in American men, other than skin cancer. The American Cancer Society estimates that there will be 186,320 new cases of prostate cancer in the United States in 2008. About 28,660 men will die of this disease this year and PCa remains the second-leading cause of cancer death in men. One in six men will get PCa during his lifetime and one in 35 will die of the disease. Today, more than 2 million men in the United States who have had PCa are still alive. The death rate for PCa continues to decline, chiefly due to early detection and treatment, and improved salvage therapy such as hormone therapy (HT). HT continues to be a mainstay for primary-recurrent PCa and locally-advanced PCa. However, HT is associated with many undesirable side effects including sexual dysfunction, osteoporosis and hot flashes, all of which can lead to decreased quality of life (QOL). These risks are seen in both long- and short-term HT regimens. Additionally, research in recent years has revealed trends related to clinico pathological variables and their predictive ability in HT outcomes. Awareness of the potential adverse effects, the risks associated with HT and the prognostic ability of clinical and pathological variables is important in determining optimal therapy for individual patients. A rigorous evaluation of the current scientific literature associated with HT was conducted with the goal of identifying the most favorable balance of benefits and risks associated with HT.

Six-month gonadotropin releasing hormone (GnRH) agonist depots provide efficacy, safety, convenience, and comfort

Two different 6-month GnRH agonist depot formulations approved for palliative treatment of advanced and metastatic prostate cancer in the United States - leuprolide acetate 45 mg and triptorelin pamoate 22.5 mg - provide patients with efficacy and safety comparable to those of existing 1-, 3-, and 4-month GnRH agonist depots. However, the 6-month formulations can increase patient convenience, comfort, and compliance by reducing the number of physician visits and injections required. At the conclusion of their pivotal trials, the 6-month formulations demonstrated efficacy rates in achieving chemical castration (serum testosterone ≤50 ng/dL) that ranged between 93% and 99%. As with existing GnRH agonist depot formulations, hot flashes represented the most common adverse event reported in trials of 6-month leuprolide acetate or triptorelin. As such, these products may prove useful not only for their labeled indication, but also as adjuncts to other treatments such as radical prostatectomy, radiotherapy, and chemotherapy. We recommend further research, including head-to-head trials between the 6-month GnRH depots, to refine our understanding of these products.

Efficacy and safety of androgen deprivation therapy after switching from monthly leuprolide to monthly degarelix in patients with prostate cancer

OBJECTIVES

To evaluate whether switching prostate cancer (PCa) patients from leuprolide to degarelix is associated with any change in the efficacy of testosterone suppression or safety profile during the first 3 months.

METHODS

Participants were 134 patients with histologically confirmed PCa who had completed 1 year of treatment with leuprolide 7.5 mg monthly before being switched to degarelix. These patients were re-randomised for the extension trial to receive a starting dose of 240 mg degarelix followed by monthly maintenance doses of either 80 (n = 69) or 160 mg (n = 65). For efficacy assessment, serum testosterone, prostate-specific antigen (PSA), luteinising hormone (LH) and follicle-stimulating hormone (FSH) levels measured at days 3, 7, 14, 28, 56 and 84 assessed whether treatment efficacy is sustained. Safety and tolerability assessments included adverse events (AEs), physical examinations, electrocardiograms and clinically significant changes in laboratory safety parameters.

RESULTS

Serum testosterone, LH, and PSA levels were all sustained in both treatment arms during the observation period. Interestingly, FSH levels were further decreased by 30% following the switch to degarelix. With the exception of injection site reactions, the overall prevalence and pattern of AEs during the first 3 months after the switch was comparable to that during the last 3 months leuprolide treatment in the main trial. There were five (4%) patients discontinued to treatment-related AEs including injection site pain (n = 3) and fatigue (n = 2).

CONCLUSIONS

This 3-month analysis indicates that patients with prostate cancer can be safely switched from leuprolide to degarelix treatment with sustained efficacy as measured by biochemical markers.

Cost-effectiveness analysis of LHRH agonists in the treatment of metastatic prostate cancer in Italy

OBJECTIVES

Luteinizing hormone-releasing hormone (LHRH) agonists represent one of the main cost factors in the management of patients with metastatic prostate cancer. We compared the cost-effectiveness of the five different 3-month formulations of LHRH agonists currently available for advanced prostate cancer in Italy, because these differ both in their capacity to suppress testosterone and in their acquisition costs.

METHODS

A probabilistic, patient-level simulation model was developed to compare the cost-effectiveness, from the perspective of the Italian National Health Service (INHS), of leuprorelin 11.25 mg and 22.5 mg, triptorelin 11.25 mg, buserelin 9.9 mg, and goserelin 10.8 mg. The model incorporated testosterone-dependent progression-free and cancer-specific survival functions, LHRH agonist effectiveness data, and national costs and tariffs. Cox's proportional hazard models were used to compute total and progression-free survival functions based on clinical data from 129 patients with metastatic prostate cancer treated in an Italian center. Bayesian random effects models were employed to summarize evidence from published literature on testosterone suppression obtained with the available LHRH agonists.

RESULTS

Estimated total survival was ≈5 years, with a maximum difference between treatment options of ≈2 months. There was a mean difference of almost €2,500 in lifetime total costs between the least costly option (leuprorelin 22.5 mg) and the most expensive (goserelin). In the incremental cost-effectiveness analysis, leuprorelin 22.5 mg dominated all alternatives except buserelin, which had an incremental cost-effectiveness ratio versus leuprorelin 22.5 mg of ≈€12,000 per life-month gained.

CONCLUSIONS

Based on modelling with meta-analysis of comparative survival data, leuprorelin 22.5 mg was the most cost-effective treatment of the available depot formulation LHRH agonists.

Should we follow-up serum testosterone in patients with advanced prostate cancer?

Agonistic analogs of luteinizing hormone-releasing hormones are indicated for the palliative treatment of metastatic prostate cancer. While the prognostic role of prostate-specific antigen in patients submitted to androgen-deprivation therapy has been extensively investigated in these patients, there is no consensus about the utility of serum testosterone measurements during follow-up and about their possible prognostic value. Recent reports have shown that testosterone levels might be directly related to survival and risk of death. These results need to be confirmed by further prospective studies. Given this concept, lowering testosterone as much as possible should be the goal of androgen-deprivation therapy in patients with metastatic prostate cancer, as this may have an impact on patient survival.

Testosterone levels in patients with metastatic prostate cancer treated with luteinizing hormone-releasing hormone therapy: prognostic significance?

OBJECTIVE

To determine if the testosterone level achieved with androgen-deprivation therapy (ADT) is directly related to survival and risk of death in men with metastatic prostate cancer, as agonistic analogues of luteinizing hormone-releasing hormones (LHRH) are indicated for palliative treatment of these patients, but there is no consensus about the utility of serum testosterone measurements during the follow-up, and their possible prognostic value.

PATIENTS AND METHODS

We retrospectively reviewed 129 consecutive patients with a histological diagnosis of metastatic bony-only prostate cancer and previously untreated with ADT. They were treated with 3 months of goserelin. Testosterone and prostate-specific antigen (PSA) levels were measured in all patients every 3 months for the duration of the follow-up. The following variables were recorded: age, stage, Gleason score, basal PSA level, basal testosterone level, PSA nadir, time to PSA nadir, testosterone after 6 months, testosterone nadir and time to testosterone nadir. Data were analysed using Cox's proportional hazards models, with the primary endpoint being cancer-specific survival.

RESULTS

The mean (SD) basal PSA level was 185.8 (344.1) ng/mL, and the mean nadir PSA level 2.7 (8.6) ng/mL. The mean testosterone levels at baseline, 6 months and the nadir were 440 (200), 40 (40) and 21 (15) ng/dL. With a mean follow-up of 47.5 (29.7) months, 71 patients were dead (55%) and 78 were alive (45%) at the time of analysis. Statistical analysis using Cox's model showed that in these patients the risk of death was directly correlated not only to Gleason score (P < 0.01) and to the 6-month PSA level (P < 0.01), but also to the 6-month serum testosterone level (hazard ratio 1.32, P < 0.05).

CONCLUSION

These results suggest a direct correlation between the risk of death and testosterone levels achieved during ADT. Based on the present results, lowering the testosterone level as much as possible should be the goal of ADT in patients with metastatic prostate cancer, as this might affect patient survival.

[Physiopathological mechanism of hot flushes-perspiration induced by androgen deprivation in prostate carcinoma]

Hot flushes and perspiration are common problems during androgen deprivation therapy for prostate carcinoma, and largely contribute to worsen patient quality of life. Different hypotheses have been proposed to explain the underlying physiopathological mechanisms, though all are very complex, basically because of the multiple causal factors involved. The present review offers a pondered and updated perspective of the origin of hot flushes-perspiration in such patients. Negative feedback of the plasma sexual hormones upon the hypothalamic secretion of noradrenalin and serotonin appears to be the main cause. Likewise, the direct action of such mechanisms upon the LH-RH producing hypothalamic center located close to the thermoregulatory center, together with shortening of the thermoneutral interval, would also play a role. Improved understanding of the causal mechanism may help improve the treatment of such symptoms.

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.

Patient rationale in selecting androgen deprivation (PRISAD): do we give patients what they want?

To assess patient rationale in selecting androgen deprivation, structured telephone interviews were conducted on consecutive patients on androgen deprivation over a 17-year period. The majority of these patients have stable disease that require long-term follow-up with 6-monthly PSA estimations. Synchronous PSA check with depot injections are preferred by majority of patients and longer intervals between the depot administrations are preferable due to perceived less needle pain. This study highlights for the first time patients' preferences for synchronous PSA check with their depot injections and a longer interval between the depot administrations due to perceived less needle pain.

Failure to achieve a PSA level <or=1 ng/mL after neoadjuvant LHRHa therapy predicts for lower biochemical control rate and overall survival in localized prostate cancer treated with radiotherapy

PURPOSE

To investigate whether failure to suppress the prostate-specific antigen (PSA) level to <or=1 ng/mL after >or=2 months of neoadjuvant luteinizing hormone-releasing hormone agonist therapy in patients scheduled to undergo external beam radiotherapy for localized prostate carcinoma is associated with reduced biochemical failure-free survival.

METHODS AND MATERIALS

A retrospective case note review of consecutive patients with intermediate- or high-risk localized prostate cancer treated between January 2001 and December 2002 with neoadjuvant hormonal deprivation therapy, followed by concurrent hormonal therapy and radiotherapy was performed. Patient data were divided for analysis according to whether the PSA level in Week 1 of radiotherapy was <or=1.0 ng/mL. Biochemical failure was determined using the American Society for Therapeutic Radiology and Oncology (Phoenix) definition.

RESULTS

A total of 119 patients were identified. The PSA level after neoadjuvant hormonal deprivation therapy was <or=1 ng/mL in 67 patients and >1 ng/mL in 52. At a median follow-up of 49 months, the 4-year actuarial biochemical failure-free survival rate was 84% vs. 60% (p = 0.0016) in favor of the patients with a PSA level after neoadjuvant hormonal deprivation therapy of <or=1 ng/mL. The overall survival rate was 94% vs. 77.5% (p = 0.0045), and the disease-specific survival rate at 4 years was 98.5% vs. 82.5%.

CONCLUSIONS

The results of our study have shown that patients with a PSA level >1 ng/mL at the beginning of external beam radiotherapy after >or=2 months of neoadjuvant luteinizing hormone-releasing hormone agonist therapy have a significantly greater rate of biochemical failure and lower survival rate compared with those with a PSA level of <or=1 ng/mL. Patients without adequate PSA suppression should be considered a higher risk group and considered for dose escalation or the use of novel treatments.

Pharmacotherapy for prostate cancer, with emphasis on hormonal treatments

For more than half a century, hormonal therapy has been one of the cornerstones of prostate cancer therapy. However, the position and timing of androgen deprivation therapy is continuously challenged. Nowadays, it is often combined with other types of treatment in a multi-modal approach, especially with radiation therapy. Besides the well-known luteinising hormone-releasing hormone agonists, several developments have been introduced (e.g., luteinising hormone-releasing hormone antagonists or improved depot formulations achieving a better pharmacokinetic slope and lower testosterone levels). Research developments include a better understanding of the different gonadotropin-releasing hormone isoforms, the ligand-independent transformation of the androgen receptor and androgen receptor overexpression in hormone-insensitive disease. Prostate cancer, previously thought to be chemotherapy insensitive, is now treated at the metastatic stage by taxane-based chemotherapies. The combination of hormonal therapy and chemotherapy is currently studied at various stages of the disease, as early as localised or locally advanced prostate cancer. It is very likely that, in the future, pharmacological treatment for prostate cancer will include combination therapies rather than monotherapies. The authors suggest an in-depth re-evaluation of the place of androgen deprivation therapy in prostate cancer.

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.

Testosterone replacement for hypogonadism after treatment of early prostate cancer with brachytherapy

BACKGROUND

Controversy and a notable paucity of published clinical data best characterize the current knowledge of testosterone-replacement therapy (TRT) for hypogonadism after treatment for early, localized prostate cancer. The objective of this study was to assess the risk of biochemical failure with TRT after treatment of early prostate cancer with permanent transperineal brachytherapy with or without external beam therapy in patients with low serum levels of testosterone and clinical symptoms of hypogonadism.

METHODS

Patients who underwent prostate brachytherapy from 1996 to 2004 and received subsequent TRT for symptomatic hypogonadism were reviewed to detail cancer characteristics and treatment as well as pre- and post-TRT serum testosterone and prostate-specific antigen (PSA) values.

RESULTS

Thirty-one men received TRT after prostate brachytherapy for 0.5 to 8.5 years (median, 4.5 years), with a follow-up that ranged from 1.5 years to 9.0 years (median, 5.0 years) postbrachytherapy. TRT was started from 0.5 years to 4.5 years (median, 2.0 years) after brachytherapy. Serum total testosterone levels ranged from 30 ng/dL to 255 ng/dL (median, 188 ng/dL) before TRT and rose to 365 ng/dL to 1373 ng/dL (median, 498 ng/dL) on TRT. Transient rises in PSA were observed in 1 patient. The most recent PSA level was <0.1 ng/mL in 23 patients (74.2%), <0.5 ng/mL in 30 patients (96.7%), and <1 ng/mL in 31 patients (100%). No patients stopped TRT because of cancer recurrence or documented cancer progression.

CONCLUSIONS

For patients with low serum testosterone levels and symptoms of hypogonadism, TRT may be used with caution and close follow-up after prostate brachytherapy.

Pilot evaluation of selective serotonin reuptake inhibitor antidepressants in hot flash patients under androgen-deprivation therapy for prostate cancer

PURPOSE

Hot flash (HF) is a common side effect in prostate cancer patient undergoing androgen-deprivation therapy (ADT). In this study, we evaluated the efficacy of paroxetine (selective serotonin reuptake inhibitors (SSRIs)) for HF.

PATIENTS AND METHODS

In total, 10 men with prostate cancer under ADH who were suffering with HF entered this study. Self-report questionnaire was used for the evaluation.

RESULTS

The average rating for HF frequency decreased (P=0.009) and HF severity decreased (P=0.0332) also, reported QOL score increased (P=0.0218).

CONCLUSION

These preliminary data suggest that low dose (10 mg/day) of antidepressant paroxetine can be helpful in the treatment of HFs in patients under ADT for prostate cancer. Further controlled studies are needed to more fully evaluate the efficacy of the SSRIs.

Testosterone recovery and changes in bone mineral density after stopping long-term luteinizing hormone-releasing hormone analogue therapy in osteoporotic patients with prostate cancer

OBJECTIVE

To investigate the rate of testosterone recovery and changes in bone mineral density in patients found to be osteoporotic while receiving luteinizing hormone-releasing hormone (LHRH) analogues after changing to antiandrogen monotherapy in an attempt to reduce further demineralization.

PATIENTS AND METHODS

Fifteen patients receiving LHRH analogue therapy for > or = 1 year were identified as osteoporotic by distal forearm dual X-ray densitometry. They were then converted to antiandrogen monotherapy, and prostate specific-antigen (PSA) and total testosterone monitored at 3-monthly intervals. The forearm densitometry was repeated at 1 year.

RESULTS

All patients had some testosterone recovery; the mean (range) duration to initial detectable testosterone was 12.8 (6-22) months. Six patients had a normal testosterone level after a mean of 17.5 (14-30) months. In the year after stopping LHRH analogue therapy the mean bone mineral density (t-score) decreased by 7.2%.

CONCLUSIONS

Osteoporotic patients, after stopping LHRH analogues, continue to have suppressed levels of testosterone which have a detrimental effect on bone mineral density. We therefore would not advocate conversion to antiandrogen monotherapy to improve bone density, and suggest alternative therapeutic intervention e.g. bisphosphonate therapy, for these patients.

Similar frequency of testosterone surge after repeat injections of goserelin (Zoladex) 3.6 mg and 10.8 mg: Results of a randomized open-label trial

OBJECTIVES

To investigate whether testosterone surges occur on repeat injections of 3.6 or 10.8 mg goserelin (Zoladex) depot and, if so, their extent.

METHODS

Men with prostate cancer for whom hormonal therapy was indicated were randomized to open-label goserelin 3.6 mg every 28 days (n = 129) or 10.8 mg every 84 days (n = 118) for 48 weeks. Serum testosterone and luteinizing hormone levels were measured before repeat injection on day 1 of each treatment cycle and then on days 4 and 8. Surges were defined in three ways: type 1, simultaneous increase in both testosterone and luteinizing hormone to within the age-specific normal range; type 2, increase in testosterone to within the age-specific normal range; and type 3, elevation in testosterone from less than to greater than the castrate level (greater than 18.5 ng/dL).

RESULTS

Most patients did not experience a testosterone surge. Two patients (1.8%) in the 10.8-mg group had a type 1 surge after one repeat injection and two (1.6%) in the 3.6-mg group had a type 2 surge after one repeat injection. Type 3 surges occurred after one or more repeat injections in 34 (27.0%) and 20 (17.7%) patients in the 3.6-mg and 10.8-mg groups, respectively (P = 0.065); the mean surge (+/- standard deviation) was 11.2 ng/dL (+/-13.5) and 17.3 ng/dL (+/-24.6), respectively. No patient with a testosterone surge had clinical symptoms of a tumor flare reaction.

CONCLUSIONS

The testosterone levels were consistently maintained within the castrate range (18.5 ng/dL or less) in most (77.4%) patients receiving long-term 3.6 mg or 10.8 mg goserelin.

Suppression of puberty with long-acting goserelin (Zoladex-LA): effect on gonadotrophin response to GnRH in the first treatment cycle

BACKGROUND AND OBJECTIVES

Depot GnRH analogues are widely used in the treatment of precocious puberty, or suppression of relatively early puberty where growth or psychosocial well-being may be compromised. One example is Zoladex (Z goserelin 3.6 mg), which can be given every 4 weeks. This injection frequency may not always achieve adequate suppression of pubertal signs. A long-acting form, Zoladex-LA 10.8 mg, has now been introduced with a potential duration of action of 12 weeks. In order to assess the efficacy of Zoladex-LA in gonadotrophin suppression we have measured LH and FSH responses to GnRH at diagnosis and 8 and 12 weeks after injection in a group of children treated with Zoladex-LA for central precocious or early puberty.

METHODS

Forty-nine children (40 girls) with clinical evidence of central precocious puberty (CPP) or early puberty (EP) were started on Zoladex-LA, either de novo (n = 29) or on changing from Zoladex. Ages at diagnosis ranged from 1.7 to 10.6 years (median 7.8 years). Twenty-three had a structural cause with abnormality on magnetic resonance/computerized tomography (MR/CT) head scan, nine had a syndrome or nonspecific brain injury, and in 17 the cause was idiopathic.

RESULTS

At diagnosis, in the de novo group, median peak LH was 13.6 IU/l and median peak FSH was 12.0 IU/l. By 12 weeks gonadotrophins were suppressed to 0.9 and 0.8 IU/l, respectively. In the previously treated group, median peak LH at diagnosis was 12.8 IU/l and median peak FSH was 15.0 IU/l with suppression to 0.8 and 1.1 IU/l, respectively, at 12 weeks. In the latter group peak FSH was higher than peak LH at both 8 and 12 weeks (P < 0.05) and there was a significant rise in peak LH (P < 0.05) and FSH (P = 0.01) between 8 and 12 weeks. There was no correlation between age at diagnosis and peak LH or FSH at 8 or 12 weeks. Nevertheless, individual patients in both groups showed evidence of incomplete gonadotrophin suppression at 12 weeks.

CONCLUSION

Zoladex-LA induces a significant reduction in gonadotrophins over 12 weeks. However, there are individuals, particularly those previously on Zoladex, in whom gonadotrophin suppression is waning by 12 weeks. As found with Zoladex, some children with precocious puberty treated with Zoladex-LA may require increased injection frequency, although correlation with clinical evidence of suppression needs to be studied further.

An in vivo/in vitro comparison with a leuprolide osmotic implant for the treatment of prostate cancer

An osmotically driven implantable system was designed and characterized for the delivery of leuprolide over a year-long duration. Leuprolide has been used in the treatment of prostate cancer since the 1980s. The DUROS implant consists of a titanium alloy cylinder, measures 4 mm in diameter by 45 mm in length and holds approximately 150 microl of formulation. Stability studies indicated that leuprolide was stable, as a solution formulation in DMSO, for several years at 37 degrees C. In vitro release rate testing, at weekly intervals, showed zero-order delivery for 1 year. DUROS implants demonstrated release rates that were reproducible and similar to one another after storage at 25 degrees C for 18 months prior to testing. In vivo studies, with implants placed subcutaneously, revealed delivery rates comparable to those observed under in vitro conditions. Leuprolide stability was also comparable between in vivo and in vitro conditions. Steady leuprolide serum levels produced by the implant resulted in the desired pharmacodynamic efficacy endpoint of testosterone suppression, both in canines and in humans. The good agreement between in vivo/in vitro delivery rates was as expected for a delivery system based on the principles of osmosis.

Clinical pharmacokinetics of goserelin

Goserelin is a synthetic decapeptide analogue of luteinising hormone-releasing hormone (LHRH). For experimental purposes it has been administered subcutaneously as an aqueous solution, but for therapeutic use it is formulated as subcutaneous depots releasing goserelin over periods of 1 (3.6 mg) or 3 (10.8 mg) months. Pharmacokinetic data have been generated using a specific radioimmunoassay. When administered as a solution, goserelin is rapidly absorbed and eliminated from serum with a mean elimination half-life (t1/2beta) of 4.2 hours in males and 2.3 hours in females. The shapes of the observed serum goserelin profiles following administration of the depots are primarily determined by the rate of goserelin release from the biodegradable lactide-glycolide copolymer matrix over periods of 1 or 3 months. There is no clinically relevant accumulation of goserelin during multiple administration of these depots. Goserelin is extensively metabolised prior to excretion. Its pharmacokinetics are unaffected by hepatic impairment, but the mean t1/2beta increases to 12.1 hours in patients with severe renal impairment. This suggests that the total renal clearance (renal metabolism and unchanged drug) is decreased in patients with renal dysfunction. It is unnecessary to adjust the dose or administration interval when the depot formulations are administered to elderly patients or to those with impaired renal or hepatic function. Administration of a goserelin 3.6 mg or 10.8 mg depot results in an initial increase of luteinising hormone (LH) levels and in increases of serum testosterone or oestradiol levels in males and females, respectively. This is followed by a decrease in serum LH levels and suppression of testosterone or oestradiol to within the castrate or menopausal range, respectively. Subsequently, throughout treatment with goserelin depots, serum testosterone or oestradiol levels remain suppressed. Clinical outcomes following treatment of patients with prostate cancer, breast cancer and benign gynaecological conditions with goserelin are described briefly.