Comparison of goserelin and leuprolide in combined androgen blockade therapy

Degarelix as a neoadjuvant hormonal therapy for acute urinary tract toxicity associated with external beam radiotherapy for intermediate- and high-risk prostate cancer: a propensity score matched analysis

BACKGROUND

In prostate cancer treatment, lower urinary tract symptoms significantly improve with luteinizing hormone-releasing hormone antagonists use compared with agonists. However, it is unclear whether luteinizing hormone-releasing hormone antagonists can decrease acute urinary tract toxicity during external beam radiotherapy. This study aimed to assess whether luteinizing hormone-releasing hormone antagonists used as neoadjuvant therapy reduced acute urinary tract toxicity during external beam radiotherapy compared with luteinizing hormone-releasing hormone agonists.

METHODS

The study included 78 patients who underwent intensity-modulated radiation therapy for intermediate- and high-risk prostate cancer between April 2013 and January 2020. Irradiation was initiated after 3-6 months of neoadjuvant therapy. Androgen deprivation therapy was given to the intermediate-risk group for 6 months and the high-risk group for 2-3 years. The European Organization for Research and Treatment of Cancer/Radiation Therapy Oncology Group toxicity grading scale was used to evaluate the urinary tract system toxicity. Relevant clinical factors were used in matching patients based on propensity scores to enable comparison between the groups.

RESULTS

Each group had 27 matched patients. There was no reduction in urinary tract toxicity with the use of luteinizing hormone-releasing hormon antagonists (P = 0.624). For patients with an International Prostate Symptom Score of ≥11 at the start of treatment, 18 patients in each group were matched. Significantly lower scores were observed in the luteinizing hormone-releasing hormon antagonist group (P = 0.041).

CONCLUSIONS

Luteinizing hormone-releasing hormon antagonists may reduce acute urinary tract toxicity during prostate cancer external beam radiotherapy compared with luteinizing hormone-releasing hormon agonists, in particular in patients with moderate to severe symptoms at the start of treatment.

Are all gonadotrophin-releasing hormone agonists equivalent for the treatment of prostate cancer? A systematic review

To review direct comparative studies of the gonadotrophin-releasing hormone (GnRH) agonists goserelin, triptorelin, and leuprorelin for the treatment of prostate cancer, and identify whether there are meaningful clinical differences between these agents. In June 2017, the following searches were performed independently by two reviewers in PubMed: (i) 'prostate cancer' and 'triptorelin' and 'leuprorelin', (ii) 'prostate cancer' and 'triptorelin' and 'goserelin', and (iii) 'prostate cancer' and 'goserelin' and 'leuprorelin', without time restriction. Duplicates were deleted. Relevant conference abstracts were also screened. A total of 16 direct comparative trials were identified: 12 reported on efficacy outcomes, four on safety/tolerability, and five on the convenience of administration/user perceptions. These studies are restricted in terms of patient numbers, formulations assessed, and endpoints measured; none were adequately powered for survival outcome measures. Studies reporting on efficacy endpoints did not show major differences in the ability of these GnRH agonists to reduce levels of testosterone or prostate-specific antigen. Some studies suggest differences in short- or long-term testosterone control, the rate of injection site adverse events, and patient/healthcare professional perceptions, but definitive conclusions cannot be drawn from the existing evidence. Few direct comparative trials of GnRH agonists have been conducted. Whilst GnRH agonists provide a similar castration effect, there is not enough evidence to show that GnRH agonists are equivalent.

Practical differences between luteinizing hormone-releasing hormone agonists in prostate cancer: perspectives across the spectrum of care

BACKGROUND

Androgen deprivation therapy (ADT) with luteinizing hormone-releasing hormone (LHRH) agonists is well established for the treatment of men with metastatic prostate cancer. As clear differences in efficacy, safety, or tolerability between the available LHRH agonists are lacking, the healthcare management team needs to look to practical differences between the formulations when selecting therapy for their patients. Moreover, as the economic burden of prostate cancer rises alongside earlier diagnosis and improved survival, the possibility for cost savings by using products with specific features is growing in importance.

METHODS

A review was conducted to summarize the information on the different LHRH agonist formulations currently available and offer insight into their relative benefits and disadvantages from the perspectives of physicians, a pharmacist, and a nurse.

RESULTS

The leuprorelin acetate and goserelin acetate solid implants have the advantage of being ready to use with no requirement for refrigeration, whereas powder and microsphere formulations have to be reconstituted and have specific storage or handling constraints. The single-step administration of solid implants, therefore, has potential to reduce labor time and associated costs. Dosing frequency is another key consideration, as administering the injection provides an opportunity for face-to-face interaction between the patient and healthcare professionals to ensure therapy is optimized and give reassurance to patients. Prostate cancer patients are reported to prefer 3- or 6-monthly dosing, which aligns with the monitoring frequency recommended in European Association of Urology guidelines and has been shown to result in reduced annual costs compared with 1-month formulations.

CONCLUSIONS

A number of practical differences exist between the different LHRH agonist preparations available, which may impact on clinical practice. It is important for healthcare providers to be aware and carefully consider these differences when selecting treatments for their prostate cancer patients.

Role of maximum androgen blockade in advanced prostate cancer

Androgen ablation is the mainstay treatment for advanced prostate cancer (PC). Researchers proposed that maximum androgen blockade (MAB) therapy with antiandrogen agent in combination with castration might result in a better outcome among patients with advanced PC. In the last two decades, numerous trials and pooled data analyses were conducted to optimize the role of MAB in the treatment of metastatic PC. Non-steroidal antiandrogens administered as part of MAB proved to have a small (3%) survival benefit, however, the magnitude of this difference is of questionable clinical significance. Available evidence suggests that MAB should not be routinely offered to patients with metastatic PC, however, it should remain a reasonable option when discussing management. The standard first line treatment should be a monotherapy, consisting of orchiectomy or LHRH agonist. MAB still has a role as a short-term therapy (2-4 weeks). The ongoing large sample population based prospective studies may add new dimensions in the use of MAB in treatment of the prostate cancer in future.

Efficacy of a second line luteinizing hormone-releasing hormone agonist after advanced prostate cancer biochemical recurrence

PURPOSE

Men with castrate resistant prostate cancer have limited treatment options. Although luteinizing hormone-releasing hormone agonists are in the same class, they are slightly different in their pharmacology. We determined whether rechallenging patients with prostate cancer, who were receiving a luteinizing hormone-releasing hormone analogue but had progression, with a different luteinizing hormone-releasing hormone analogue (goserelin or leuprolide acetate) would result in a prostate specific antigen response. Secondary objectives were to calculate the PSA response and determine whether sequence order impacted the response.

MATERIALS AND METHODS

We performed a retrospective, ethics approved review of the records of patients with prostate cancer at multiple institutions who received a luteinizing hormone-releasing hormone analogue (goserelin or leuprolide acetate), experienced progression, as measured by 2 consecutive prostate specific antigen increases, and were rechallenged with the other analogue (goserelin or leuprolide acetate). Prostate specific antigen and relevant clinical data were obtained and statistical analysis was done.

RESULTS

Of 39 available men 27 (69%) had decreased prostate specific antigen after 3 months of switching regimens. The median change in prostate specific antigen was -1.5 (IQR -10.0, 0.8), indicating a statistically significant decrease (p=0.01). The median percent prostate specific antigen change for leuprolide acetate to goserelin was -69.3% (IQR -81.5, 26.2) and for goserelin to leuprolide acetate it was -6.4% (IQR -61.7, 21.8, p=0.05). Median time to a subsequent prostate specific antigen increase was 5.2 months (95% CI 3.5-17.4).

CONCLUSIONS

Prostate specific antigen decreased after switching luteinizing hormone-releasing hormone therapies. This decrease appeared most significant in the group that switched from leuprolide acetate to goserelin. The duration of response after switching was approximately 5 months. The study is limited by its retrospective nature but should encourage prospective evaluation of this observation.

Evidence-based medicine: comparative analysis of luteinizing hormone-releasing hormone analogues in combination with external beam radiation and surgery in the treatment of carcinoma of the prostate

What's known on the subject? and What does the study add? Luteinizing hormone-releasing hormone analogues are a cornerstone in the management of many clinical situations in prostate cancer patients. The multiplicity of drugs make it difficult to decide which is the best drug to prescribe to each patient. Whether or not the different luteinizing hormone-releasing hormone analogues belong to the same drug class is only merely supposed. This study adds a systematic review of the literature in order to determine whether or not the luteinizing hormone-releasing hormone analogues available for prescription belong to the same drug class (same family, similar chemical structure, mechanism of action, and efficacy). The current evidence available is not enough to support a presumed drug class effect of the various analogues in the treatment of prostate carcinoma.

OBJECTIVE

• To study whether luteinizing hormone-releasing hormone (LHRH) analogues are agents of the same pharmacological class, i.e. whether they have the same clinical effect, using an evidence-based medicine approach.

MATERIAL AND METHODS

• We reviewed the evidence on the alleged 'drug class effect' among analogues and the existing bibliographic support for their use in various medical indications. We used PubMed as the main search source. Evidence level and degree of recommendation were assigned to each conclusion based on the 'Scottish Intercollegiate Guidelines Network'.

RESULTS

• There are no studies designed to answer the question of class effect between LHRH analogues or agonists. Reviews and meta-analyses have been performed on many other issues related to therapeutic management either with analogues alone, or in combination with radiation therapy and surgery. • Direct comparisons do not allow definitive conclusions to be reached. Indirect evidence is obtained from randomized studies comparing the different LHRH analogues with other treatments used to obtain androgen deprivation. Other issues related to pharmacokinetics and pharmacodynamics that can support either the existence or non-existence of class effect were evaluated.

CONCLUSION

• The current available evidence is not enough to support a presumed class effect of the drug among the different analogues in the treatment of prostate carcinoma in its various clinical situations.

Goserelin versus leuprolide before hysterectomy for uterine fibroids

OBJECTIVE

To compare goserelin and leuprolide given before hysterectomy for symptomatic large fibroid uteri.

METHODS

A randomized study of 66 premenopausal women with fibroid uteri at least 14 weeks of gestation in a gravid uterus. Women were randomized to receive either subcutaneous depot 3.6 mg goserelin or 3.75 mg leuprolide every 4 weeks for a total of 3 doses. Hysterectomy was performed within 1 month of the last dose.

RESULTS

A total of 34 women randomized to the goserelin group and 31 women to the leuprolide group were available for analysis. Preoperative hemoglobin level (P=0.89), operative blood loss (P=0.72), and operating time (P=0.39) were not different between the 2 groups. Postoperative hemoglobin was higher in the leuprolide group (P=0.003), but blood transfusion requirement was not different between the groups (P=1.0). Other outcomes and side effects of the drugs were similar.

CONCLUSIONS

Goserelin and leuprolide administered before hysterectomy for uterine fibroids have similar perioperative outcomes.

Testosterone and erectile function recovery after radiotherapy and long-term androgen deprivation with luteinizing hormone-releasing hormone agonists

OBJECTIVE

To study the recovery of testosterone levels and erectile function in men who received radiotherapy plus long-term adjuvant androgen deprivation (LTAD) with luteinizing hormone-releasing hormone (LHRH) agonists.

PATIENTS AND METHODS

From April 2000 to July 2001, men who had completed prostate radiotherapy with > or = 2 years of LTAD, and had their last LHRH agonist injection at least 6 months before, were invited to participate. At study entry, the men completed the International Index of Erectile Function (IIEF), and their serum total testosterone (TT), prostate-specific antigen, LH, follicle-stimulating hormone, haemoglobin, and body mass were measured. This assessment was repeated at 1 year.

RESULTS

In all, 20 men were recruited, with a mean (range) age of 70 (55-81) years. Defining a normal TT level as > or = 8.0 nmol/L, the median time to a normal level was 2.3 years (95% confidence interval (CI), 1.9-4.2). The median duration of castrate TT levels was 8 months (95% CI, 6.2-14.9). LH recovered before TT, suggesting that the rate-limiting step in the recovery of TT may be at the testicular level. The median time to recovery of normal LH levels was 3.8 months, compared to 8.0 months to reach supracastrate TT levels, and 2.3 years to reach normal TT levels. Age and the LH/TT ratio were associated with the time to recovery of both supracastrate and normal levels of TT. The IIEF was completed by 17 men; there were no significant changes in the scores in any domain of the IIEF during the study.

CONCLUSIONS

Most men recover supracastrate testosterone levels after LTAD and external beam radiotherapy, but recovery of 'normal' testosterone levels is slow. Few men recover potency and sexual desire. The patients age and LH/TT ratio may be predictive of the time to recovery of both supracastrate and normal testosterone levels.

The use of unequal randomisation ratios in clinical trials: a review

OBJECTIVE

To examine reasons given for the use of unequal randomisation in randomised controlled trials (RCTs).

MAIN MEASURES

Setting of the trial; intervention being tested; randomisation ratio; sample size calculation; reason given for randomisation.

METHODS

Review of trials using unequal randomisation. DATABASES AND SOURCES: Cochrane library, Medline, Pub Med and Science Citation Index.

RESULTS

A total of 65 trials were identified; 56 were two-armed trials and nine trials had more than two arms. Of the two-arm trials, 50 trials recruited patients in favour of the experimental group. Various reasons for the use of unequal randomisation were given. Six studies stated that they used unequal randomisation to reduce the cost of the trial, with one screening trial limited by the availability of the intervention. Other reasons for using unequal allocation were: avoiding loss of power from drop-out or cross-over, ethics and the gaining of additional information on the treatment. Thirty seven trials papers (57%) did not state why they had used unequal randomisation and only 14 trials (22%) appeared to have taken the unequal randomisation into account in their sample size calculation.

CONCLUSION

Although unequal randomisation offers a number of advantages to trials the method is rarely used and is especially under-utilised to reduce trial costs. Unequal randomisation should be considered more in trial design especially where there are large differences between treatment costs.

An update on bicalutamide in the treatment of prostate cancer

In this update, bicalutamide (Casodex, Zeneca Pharmaceuticals) has been confirmed as an effective, well-tolerated and convenient non-steroidal anti-androgen for advanced prostate cancer. Preclinical and clinical studies have indicated its potential as monotherapy, with quality of life advantages compared with castration. A head-to-head comparison with flutamide, where both anti-androgens were used as part of combined androgen blockade, has suggested that the choice of components in this regimen can influence outcome, and has demonstrated that bicalutamide is better tolerated than flutamide. There is also preliminary evidence to support the potential use of bicalutamide in treatment of early-stage disease and tumours that are refractory to other non-steroidal anti-androgens.

Estimating the optimal external-beam radiotherapy utilization rate for genitourinary malignancies

BACKGROUND

Benchmark radiotherapy utilization rates for genitourinary malignancies are largely unknown, despite the finding that genitourinary cancers comprise approximately 19% of all registered malignancies in Australia.

METHODS

To develop an evidence-based benchmark of the optimal proportion of patients with genitourinary malignancies who should receive at least one course of radiotherapy at some time during their illness, the authors studied treatment guidelines and treatment reviews regarding genitourinary malignancies. Optimal radiotherapy utilization trees were constructed to show the clinical attributes that indicated possible benefit from radiotherapy based on evidence. Epidemiologic incidence data for each of these clinical attributes were obtained to calculate the optimal proportion of all patients with genitourinary cancer for whom radiotherapy was considered appropriate.

RESULTS

The proportion of patients with genitourinary malignancies for whom radiotherapy was indicated at some point in their illness, according to the best available evidence, was estimated to be 27% of patients with renal cancer, 58% of patients with bladder cancer, 60% of patients with prostate cancer, and 49% of patients with testicular cancer. The occurrence of ureteric and penile cancers among patients was too rare, and, therefore, these patients were not included in the current study.

CONCLUSIONS

There was a large discrepancy between actual radiotherapy utilization and the evidence-based optimal rate. The authors recommended strategies to implement the evidence-based guidelines. Evidence-based benchmarks for radiotherapy utilization rates such as the ones described in the current study were important in the evaluation of the appropriate use of radiotherapy.

Bone loss and the evolving role of bisphosphonate therapy in prostate cancer

Androgen deprivation therapy (ADT) can result in significant loss of bone mineral density (BMD) but to date, there are no prospective studies that document the true severity of bone loss and resulting fracture rates. In the general population, however, the incidence of low BMD is increasing in elderly men. Men suffer more morbidity and mortality from fractures associated with low BMD than women. Problems of underdiagnosis and undertreatment in men can be addressed with enhanced awareness of the risk factors for bone loss in men and the available treatment options. Guidelines for diagnosis of low BMD in women can probably be applied to men. Treatment options have not been studied as extensively in men. For men treated with ADT for prostate cancer, however, use of intravenous zoledronic acid at the initiation of ADT has been shown to prevent and even reverse bone loss. Although the routine use of bisphosphonates to prevent bone loss is not yet recommended, zoledronic acid is a logical choice of therapy in men who have low BMD at baseline or who develop bone loss during the course of therapy. In addition to its effects on BMD, zoledronic acid has also been shown to decrease skeletal morbidity in men with metastatic hormone-refractory prostate cancer. Whether zoledronic acid or other bisphosphonates might actually prevent or delay the development of bone metastases remains to be studied in randomized clinical trials.

Bicalutamide (Casodex) in the treatment of prostate cancer

Prostate cancer is an important healthcare issue in men worldwide. With the advent of prostate-specific antigen screening and improved diagnostic techniques, prostate cancer is now being diagnosed in younger men and at earlier disease stages. As a result, patients often live with their disease for many years after diagnosis. This shift in the patient profile has focused attention to the impact of treatment on quality of life. Medical/surgical castration has traditionally been the mainstay of hormonal therapy but is associated with side effects including loss of libido and impotence. Nonsteroidal antiandrogens such as bicalutamide (Casodex) offer an effective alternative to castration with potential quality-of-life benefits. This paper reviews the evidence concerning the use of bicalutamide at all stages of the disease.

An evaluation of bicalutamide in the treatment of prostate cancer

Prostate cancer is a major health problem in men, causing significant morbidity and mortality. Although traditionally considered a disease of old age, improved diagnostic techniques have resulted in earlier diagnosis and many men are now treated while still physically and sexually active. Current therapies for prostate cancer, which include medical or surgical castration, have a significant impact on many aspects of quality of life. The non-steroidal antiandrogen bicalutamide (Casodex, AstraZeneca) has a favourable tolerability profile with demonstrated efficacy in several stages of prostate cancer and represents an alternative therapeutic strategy to castration. Mature survival data from men with previously untreated, locally-advanced disease reveal that bicalutamide monotherapy provides survival benefits that do not differ significantly from castration, while offering important advantages with respect to the maintenance of physical capacity and sexual interest. Recent data from a prospective randomised trial, the largest prostate cancer treatment study ever conducted, demonstrate that immediate therapy with bicalutamide (alone or as an adjuvant to therapy of curative intent) significantly reduces the risk of objective disease progression in patients with localised or locally-advanced prostate cancer. Antiandrogens are also used in combination with castration (combined androgen blockade) for advanced disease. Another large, randomised trial demonstrated that combined androgen blockade with bicalutamide is associated with a similar survival outcome to combined androgen blockade with flutamide and is better tolerated. The evidence reviewed demonstrates that bicalutamide currently has a favourable risk:benefit ratio in several stages of prostate cancer. The role of bicalutamide will be further defined by ongoing studies.

Luteinizing-Hormone-Releasing Hormone Agonist plus Antiandrogen Regimens in the Treatment of Advanced Prostate Cancer

The increasing complexity of cancer chemotherapy makes it mandatory that pharmacists be familiar with these highly toxic agents. This column reviews various issues related to the preparation, dispensing, and administration of cancer chemotherapy, both commercially available and investigational.

Regulation of mRNA and protein levels of beta1 integrin variants in human prostate carcinoma

Alterations of integrin expression levels in cancer cells correlate with changes in invasiveness, tumor progression, and metastatic potential. The beta1C integrin, an alternatively spliced form of the human beta1 integrin, has been shown to inhibit prostate cell proliferation. Furthermore, beta1C protein levels were found to be abundant in normal prostate glandular epithelium and down-regulated in prostatic adenocarcinoma. To gain further insights into the molecular mechanisms underlying abnormal cancer cell proliferation, we have studied beta1C and beta1 integrin expression at both mRNA and protein levels by Northern and immunoblotting analysis using freshly isolated neoplastic and normal human prostate tissue specimens. Steady-state mRNA levels were evaluated in 38 specimens: 33 prostatic adenocarcinomas exhibiting different Gleason's grade and five normal tissue specimens that did not show any histological manifestation of benign prostatic hypertrophy. Our results demonstrate that beta1C mRNA is expressed in normal prostate and is significantly down-regulated in neoplastic prostate specimens. In addition, using a probe that hybridizes with all beta1 variants, mRNA levels of beta1 are found reduced in neoplastic versus normal prostate tissues. We demonstrate that beta1C mRNA down-regulation does not correlate with either tumor grade or differentiation according to Gleason's grade and TNM system evaluation, and that beta1C mRNA levels are not affected by hormonal therapy. In parallel, beta1C protein levels were analyzed. As expected, beta1C is found to be expressed in normal prostate and dramatically reduced in neoplastic prostate tissues; in contrast, using an antibody to beta1 that recognizes all beta1 variants, the levels of beta1 are comparable in normal and neoplastic prostate, thus indicating a selective down-regulation of the beta1C protein in prostate carcinoma. These results demonstrate for the first time that beta1C and beta1 mRNA expression is down-regulated in prostate carcinoma, whereas only beta1C protein levels are reduced. Our data highlight a selective pressure to reduce the expression levels of beta1C, a very efficient inhibitor of cell proliferation, in prostate malignant transformation.

Finasteride in association with either flutamide or goserelin as combination hormonal therapy in patients with stage M1 carcinoma of the prostate gland. International Prostate Health Council (IPHC) Trial Study Group

BACKGROUND

It was very reasonable to consider that the combination of the 5alpha-reductase, finasteride, and a pure antiandrogen such as flutamide should provide an effective form of maximal androgen blockade (MAB). Finasteride decreases intraprostatic levels of 5alpha-dihydrotestosterone (DHT), and the antiandrogen would restrain the biological action of the residual DHT by interfering with its association with androgen receptor. This form of MAB should sustain the concentration of testosterone in plasma, thereby maintaining sexual function and reasonable quality of life. In order to investigate this, a randomized multicenter phase II clinical trial of patients with untreated M1 cancer of the prostate was developed and undertaken.

METHODS

Patients were randomly allocated to one of three treatment schedules: 1) goserelin, 3.6 mg, s.c., monthly in combination with flutamide, 250 mg., t.i.d. and a placebo, daily, in the image of 2 x 5 mg finasteride; 2) goserelin, 3.6 mg., s.c., monthly in combination with finasteride, 10 mg (2 x 5 mg, daily) and a placebo (t.i.d.) in the image of flutamide; and 3) finasteride, 10 mg (2 x 5 mg, daily) in combination with flutamide (250 mg, t.i.d.). The reduction in concentration of serum PSA at 24 weeks was the endpoint of interest.

RESULTS

Baseline prostate-specific antigen (PSA) levels of the patients in the three groups were very similar. There was a substantial decrease in levels of PSA in the three groups prior to the end of the study, the percent decrease in the groups being: 1) goserelin and flutamide combination, 99.1% (95% Confidence interval (CI), 97.7, 99.6); 2) goserelin and finasteride combination, 98.75% (95% CI, 97.1, 99.5); and 3) finasteride and flutamide combination, 97.6%, 95% CI, 94.5, 98.9). In the Generalized linear model (GLM) analysis, there was no center by treatment group interaction (P = 20), and there were no significant differences between centers (P = 0.059) nor among the three treatment groups (P = 0.16).

CONCLUSIONS

The decrease in levels of PSA in such a group of patients with M1 cancer of the prostate over a 24-week period was surprisingly large, and the differences in these decreased levels between the three treatment arms were remarkably small. There were no apparent differences in bone scan scores, World Health Organization (WHO) performance status, and pain scores between the arms. With regard to sexual function associated with quality of life, there were the understandable difficulties of data collection from patients treated with goserelin.