Why phase III trials of maximal androgen blockade versus castration in M1 prostate cancer rarely show statistically significant differences

[Advanced Prostate Cancer Consensus Conference (APCCC) 2015 in St. Gallen : Critical review of the recommendations on diagnosis and therapy of metastatic prostate cancer by a German expert panel]

In March 2015, the first Advanced Prostate Cancer Consensus Conference (APCC) took place in St. Gallen. 41 experts from 17 countries reviewed important areas of controversy in advanced hormone-naive and castration-resistant prostate cancer and gave therapy recommendations. These results have been recently published in "Annals of Oncology". While most of the recommendations from St. Gallen are comprehensible, some of them need to be further discussed. Therefore, we as a German expert panel will critically debate the St. Gallen recommendations. For metastatic hormone-naive prostate cancer, continuous androgen deprivation remains the standard. There is no evidence for superiority of primary maximal androgen deprivation. Patients suitable for chemotherapy, especially in the presence of high tumour burden, should receive androgen deprivation plus taxanes upfront. In metastatic castration resistant prostate cancer, novel hormonal agents like abiraterone or enzalutamid should be the treatment of choice in the majority of patients. Taxanes should be used first-line in patients with unfavourable prognostic markers. Radium-223 is an option in symptomatic patients with bone metastases. There is first evidence that second-line hormonal treatment after first-line failure of a novel endocrine agent has a high failure rate. Cabazitaxel should be part of the treatment sequence in patients with a good performance status. Baseline staging for castration-resistant prostate cancer should include CT-abdomen/-chest and bone scan. Radiographic monitoring should be performed 2 to 3 times a year. Determination of PSA and ALP is to take place every 2 to 4 months.

Androgen deprivation therapy with Leuprolide acetate for treatment of advanced prostate cancer

INTRODUCTION

Hormone sensitive advanced prostate cancer (PCa) is an incurable disease that is treated with a variety of hormonal therapies targeting the androgen/androgen receptor signaling axis. For decades androgen deprivation therapy (ADT) by surgical or chemical castration is the gold standard for the treatment of advanced PCa. Areas covered: This review discusses the pharmacological features of Leuprolide, a luteinizing hormone-releasing hormone (LHRH) agonists/analog and the most commonly used drug in ADT. Expert opinion: Although Leuprolide has been on the market for more than 30 years it is still the leading option for ADT and serves as a basis for most multimodal therapy concepts. The fact that with the onset of castration-resistance in late stage metastatic disease, a prolongation of ADT in combination with a second line hormonal manipulation is recommended supports the importance of the compound for daily clinical practice.

Degarelix monotherapy compared with luteinizing hormone-releasing hormone (LHRH) agonists plus anti-androgen flare protection in advanced prostate cancer: an analysis of two randomized controlled trials

OBJECTIVES

The objective of this study was to assess differences in efficacy outcomes between luteinizing hormone-releasing hormone (LHRH) agonist plus antiandrogen (AA) flare protection and monotherapy with the gonadotrophin-releasing hormone antagonist degarelix in patients with prostate cancer.

METHODS

Data from 1455 patients were pooled from two prospective, phase III randomized 1-year clinical trials of degarelix versus LHRH agonist with or without AA. The AA bicalutamide was administered at the investigator's discretion. Adjusted hazard ratios (HRs) were calculated using a Cox proportional hazards regression model and a conditional logistic regression model was used for a case-control analysis of odds ratios (ORs).

RESULTS

Patients received degarelix monotherapy (n = 972) or LHRH agonist (n = 483) of whom 57 also received AA. Overall, prostate-specific antigen progression-free survival (PSA PFS) was improved with degarelix versus LHRH agonist + AA (Cox proportional hazards regression model-adjusted HR for PSA PFS failure was 0.56 [95% confidence interval (CI) 0.33-0.97, p = 0.038]). To compensate for a higher proportion of patients with metastases, Gleason score 7-10, and PSA >20 ng/ml in the LHRH agonist + AA group, a case-control analysis using a conditional logistic regression model was utilized. This resulted in an OR for PSA PFS of 0.42 (95% CI 0.20-0.89; p = 0.023) in the overall population, and 0.35 (95% CI 0.13-0.96; p = 0.042) in patients with PSA >50 ng/ml at baseline, when treated with degarelix versus LHRH agonists + AA. There were a small number of deaths, 1.9% with degarelix and 7% with LHRH agonists + AA (case-control analysis OR = 0.37; p = 0.085).

CONCLUSIONS

Degarelix monotherapy produced a more favorable effect on PSA PFS outcomes than a LHRH agonist + AA flare protection therapy in patients with prostate cancer when a case-control analysis was used to compensate for differences between treatment groups.

Androgen Deprivation Therapy in Prostate Cancer - Current Status in M1 Patients

Androgen deprivation therapy is the cornerstone treatment for metastatic prostate cancer. It can be done either surgically or medically. Luteinizing hormone-releasing hormone agonists and antagonist are the most effective drugs, with different side effects and modes of action, but no clear efficacy differences. Adding a non-steroidal antiandrogen adds a marginal benefit but also significant side effects and costs. Non-steroidal antiandrogens should not be used as monotherapy. In most patients with metastases, immediate castration is the standard of care. The intermittent modality is apparently non-inferior to the continuous one, with some other benefits. Upfront chemotherapy added to castration should be considered as the new standard of care in many metastatic patients. Castration leads to many adverse effects, some potentially life-threatening such as cardiovascular side effects.

Saudi oncology society and Saudi urology association combined clinical management guidelines for prostate cancer

In this report, updated guidelines for the evaluation, medical, and surgical management of prostate cancer are presented. They are categorized according the stage of the disease using the tumor node metastasis staging system 7(th) edition. The recommendations are presented with supporting evidence level.

Contemporary role of androgen deprivation therapy for prostate cancer

CONTEXT

Androgen deprivation therapy (ADT) for prostate cancer (PCa) represents one of the most effective systemic palliative treatments known for solid tumors. Although clinical trials have assessed the role of ADT in patients with metastatic and advanced locoregional disease, the risk-benefit ratio, especially in earlier stages, remains poorly defined. Given the mounting evidence for potentially life-threatening adverse effects with short- and long-term ADT, it is important to redefine the role of ADT for this disease.

OBJECTIVE

Review the published experience with currently available ADT approaches in various contemporary clinical settings of PCa and reported serious treatment-related adverse events. This review addresses the level of evidence associated with the use of ADT in PCa, focusing upon survival outcome measures. Furthermore, this paper discusses evolving approaches targeting androgen receptor signaling pathways and emerging evidence from clinical trials with newer compounds.

EVIDENCE ACQUISITION

A comprehensive review of the literature was performed, focusing on data from the last 10 yr (January 2000 to July 2011) and using the terms androgen deprivation, hormone treatment, prostate cancer and adverse effects. Abstracts from trials reported at international conferences held in 2010 and 2011 were also evaluated.

EVIDENCE SYNTHESIS

Data from randomized controlled trials and population-based studies were analyzed in different clinical paradigms. Specifically, the role of ADT was evaluated in patients with nonmetastatic disease as the primary and sole treatment, in combination with radiation therapy (RT) or after surgery, and in patients with metastatic disease. The data suggest that in men with nonmetastatic disease, the use of primary ADT as monotherapy has not shown a benefit and is not recommended, while ADT combined with conventional-dose RT (<72Gy) for patients with high-risk disease may delay progression and prolong survival. The postoperative use of ADT remains poorly evaluated in prospective studies. Likewise, there are no trials evaluating the role of ADT in patients with biochemical relapses after surgery or RT. In patients with metastatic disease, there is a clear benefit in terms of quality of life, reduction of disease-associated morbidity, and possibly survival. Treatment with bilateral orchiectomy, luteinizing hormone-releasing hormone agonist therapy, with and without antiandrogens has been associated with various serious adverse events, including cardiovascular disease, diabetes, and skeletal complications that may also affect mortality.

CONCLUSIONS

Although ADT is an effective treatment of PCa, consistent long-term benefits in terms of quality and quantity of life are predominantly evident in patients with advanced/metastatic disease or when ADT is used in combination with RT (<72Gy) in patients with high-risk tumors. Implementation of ADT should be evidence based, with special consideration to adverse events and the risk-benefit ratio.

Saudi Oncology Society clinical management guidelines for prostate cancer

In this report, guidelines for the evaluation, medical and surgical management of testicular germ cell tumors is presented. It is categorized according to the stage of the disease using the tumor node metastasis staging system, 7th edition. The recommendations are presented with supporting level of evidence.

Hormonal status in patients with advanced prostatic cancer on the therapy with androgen blockade

Background/Aim. Hormone suppression therapy is used in men with advanced prostate cancer improving chances of longer survival. The aim of this study was to investigate the influence of androgen blockades on testosterone and luteinizing hormone (LH) values in patients with locally advanced and metastatic prostatic cancer. Methods. The study included a total of 60 patients out of which 45 with prostatic cancer divided into 3 subgroups based on the type of the applied treatment protocol: 15 patients on monotherapy with luteinizing-releasing hormone (LH-RH) agonists (group I), 15 patients on total androgen blockade (group II) and 15 patients on monotherapy with antiandrogen (group III)). The control group consisted of 15 patients with benign prostatic hyperplasia. In all the patients, values of testosteron, LH and prostatespecific antigen (PSA) were monitored initially, as well as 3 and 6 months after the treatment protocol introduction. Results. In the patients of the groups I, II and III, values of testosterone decreased after three months by 95.58%, 95.72%, and 67%, respectively. The difference was significant (p < 0.01). Between the values after three and six months there was no significant difference in these groups of participants. Testosterone values were significantly higher in the patients of the group III in both analyses. Comparing the values between the groups III and I, as well as those of the groups III and II, a significant difference was found after three and six months of the therapy (p < 0.01). There was a difference in testosterone values between the groups I and II after 3 and 6 months, but not significant. All types of the applied treatment protocols in the therapy of prostatic cancer significantly decreased the values of LH compared to the basal ones. Conclusion. Total androgen blockade and LH-RH agonists are more effective in lowering testosterone values (to castration values) compared to the antiandrogen monotherapy, where testosterone values stay above the castration level. This therapy approach has advantages, since it decreases testosterone values providing better therapy response. There is a difference in testosterone values, but not significant, when total androgen blockade and monotherapy with LH-RH agonists are administered. Registered lower basal values of LH in all patients with prostatic cancer open the possibility to introduce LH as a new additional, significant marker in diagnosis of this neoplasm.

[Androgen deprivation for advanced prostate cancer]

Androgen deprivation (ADT) by medical or surgical castration represents the standard therapeutic approach for managing prostate cancer (PCA) with systemic or locoregional metastases. Although ADT has been successfully used for more than 60 years, there are still major controversies with regard to the initiation (early versus delayed), type (complete versus monotherapy), and duration (continuous versus intermittent) of treatment. It is the purpose of this review to critically present the results of the various ADT options. Bilateral orchiectomy and subcutaneous application of luteinising hormone-releasing hormone (LHRH) analogues represent the guideline-recommended standard treatment for metastatic PCA, whereas estrogens are no longer recommended because of significant cardiovascular side effects despite comparable therapeutic efficacy. Antiandrogen monotherapy with bicalutamide is comparable to LHRH analogues in men with minimal tumour burden. However, survival rates are inferior in patients with extensive metastatic disease, in whom medical or surgical castration should be favoured. Complete ADT results in a median survival benefit of about 5% in men with low metastatic tumour burden, and it cannot be recommended for routine use. Early ADT is associated with a significant advantage in terms of symptom-free survival and prevention of metastasis-associated complications, but it does not result in a prolonged progression-free and overall survival when compared with delayed ADT. Despite encouraging results, intermittent ADT remains an experimental therapeutic approach that should be considered on an individual basis in carefully selected patients. Adjuvant ADT is still discussed controversially for men after radical prostatectomy, whereas it has become the standard approach in patients who undergo external beam radiation for locally advanced PCA.

Economical impact of orchiectomy for advanced prostate cancer

PURPOSE

To demonstrate the economical impact of surgical castration in comparison to the medical castration for patients with advanced prostate cancer.

MATERIAL AND METHODS

Between January 2001 and December 2001, 32 patients with advanced prostate cancer underwent bilateral sub-capsular orchiectomy at our Hospital. The costs of this procedure were compared to the costs of medical castration with LH-RH analogues.

RESULTS

The costs of the surgical procedure were extremely reduced when compared to published data on the medical treatment. Surgical castration did not have any stronger negative impact on the evolution of these patients when compared to medical castration.

CONCLUSION

Surgical castration is an efficient and low cost treatment for advanced prostate cancer.

Immediate Versus Deferred Hormonal Treatment for Patients With Prostate Cancer Who Are Not Suitable for Curative Local Treatment: Results of the Randomized Trial SAKK 08/88

Purpose

To determine if immediate hormonal therapy is advantageous compared with deferred treatment in newly diagnosed asymptomatic prostate cancer patients who, for any reason, were not candidates for curative local treatment.

Patients and Methods

Between February 1988 and February 1992, 197 patients with a median age of 76 years (range, 56 to 86 years) were randomly assigned to receive either immediate or deferred orchiectomy on symptomatic progression. The two groups did not differ significantly in clinical or laboratory parameters; 67% had T3-4 tumors and 20% had lymph node metastases. Patient accrual was stopped prematurely because of a similar competing trial. Therefore, observation time was prolonged to achieve the desired number of events and statistical power.

Results

Deferred orchiectomy was necessary in 58% of the patients. Median time to disease progression was 2.8 years less than for patients with immediate orchiectomy. However, overall pain-free time from random assignment to symptomatic progression after immediate or deferred orchiectomy, and performance status, were identical in both groups. Cancer-specific survival tended to be longer in the immediate group (P = .09) but there was no difference in overall survival between the two groups (P = .96). The median hemoglobin value decreased significantly after immediate orchiectomy (P < .001).

Conclusion

For elderly, asymptomatic patients not undergoing curative local treatment, we were unable to show any major advantage of immediate compared with deferred hormonal treatment regarding quality of life or overall survival in our limited number of patients. Disabling complications were prevented in the deferred-treatment arm by careful follow-up; 42% of these patients never required any tumor-specific treatment.

The truth is out there: an overall perspective on androgen deprivation

Androgen deprivation therapy (ADT) is a mainstay in the treatment of prostate cancer. The ideal timing, duration and composition of ADT remains undefined. At the present time, first-line therapy consists of orchiectomy, LHRH agonists, or combined androgen blockade (CAB). However, new combinations and treatment settings show promise for improving outcomes and decreasing toxicity.

The development of androgen-independent prostate cancer

The normal prostate and early-stage prostate cancers depend on androgens for growth and survival, and androgen ablation therapy causes them to regress. Cancers that are not cured by surgery eventually become androgen independent, rendering anti-androgen therapy ineffective. But how does androgen independence arise? We predict that understanding the pathways that lead to the development of androgen-independent prostate cancer will pave the way to effective therapies for these, at present, untreatable cancers.