A randomized double-blind study evaluating Anandron associated with orchiectomy in stage D prostate cancer

Assessing novel analogues of nilutamide as a human androgen receptor antagonist: A detailed investigation of drug design using a bioisosteric methodology including ADMET profiling, molecular docking studies and molecular dynamics simulation

Cancer is a significant health and economic concern worldwide. Prostate cancer (PC) ranks as the fourth leading cause of global death and is the second most prevalent malignancy in males. Androgens are essential for the progress and growth of the prostate gland. PC is caused by androgens binding to receptors, which activates genes that promotes the development of PC. Nilutamide (NLM) is an antiandrogen medicine used in the treatment of PC. However, throughout treatment, it induces various toxicities and leads to resistance in patients. The objective of the work was to designed and evaluated safer NLM analogues using computational approaches with optimized pharmacokinetic profiles and less toxicity. Newer bioisosteres of the designed NLM analogues and their ADMET scores were calculated using the MolOpt and ADMETlab 3.0 tools, respectively. We conducted docking investigations of the designed ligands using AutoDock Vina software. The MolOpt web server produces 1575 bioisosteres of NLM using the scaffold transformation method. The 47 bioisosteres were selected based on pharmacokinetic profiles, drug likeness (DL) and drug score (DS) prediction scores and were determined to be optimum to excellent in comparison to NLM. The analogues NLM28, NLM31, NLM34, NLM38, NLM40, NLM44, NLM45, and NLM47 exhibited favorable interactions and docking scores with the protein (PDB ID: 2AM9). The molecular dynamics (MD) simulation results revealed that the NLM34 and NLM40 complexes were found stable during the 100 ns run. The findings indicate that the NLM analogues, particularly NLM34 and NLM40 have the potential to be used as promising antiandrogen agents for PC therapy.

Efficacy and Safety of Non-Steroidal Anti-Androgens in Patients with Metastatic Prostate Cancer: Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Prostate cancer (PCa) is the sixth primary cause of cancer death. However, conflicts are present about the efficacy and safety of Non-steroidal anti-androgens (NSAA) for its treatment. The aim of this study was to assess the efficacy and safety of NSAAs versus any comparator for the treatment of advanced or metastatic PCa (mPCa).

METHODS

MEDLINE and the Cochrane Library were searched. References of included studies and clinicaltrials.gov were also searched for relevant studies. Only English language studies after 1990 were considered for review. Randomized controlled trials (RCTs) examining the efficacy and safety of NSAAs as compared with any other comparator including surgery or chemotherapy in mPCa patients were included. The outcomes include efficacy, safety and the tolerability of the treatment. The Cochrane Risk of Bias Assessment Tool was used for quality assessment. Two authors were independently involved in the selection, extraction and quality assessment of included studies and disagreements were resolved by discussion or by consulting a third reviewer.

RESULTS

Fifty-eight out of 1307 non-duplicate RCTs with 29154 patients were considered for the review. NSAA showed significantly better progression-free survival [PFS] (Hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.46-0.78; P=0.0001), time to distant metastasis or death [TTD] (HR, 0.80; 95% CI 0.73-0.91; P<0.0001), objective response (Odds ratio [OR], 1.64; 95% CI 1.06-2.54; P=0.03) and clinical benefits (OR, 1.33; 95% CI 1.08-1.63; P=0.006) as compared to the control group. There was no significant difference observed between the groups in terms of overall survival (HR, 0.95; 95%CI, 0.87-1.03; P=0.18) and time to progression (HR, 0.93; 95% CI 0.77-1.11; P=0.43). Treatment-related adverse events were more with the NSAA group, but the discontinuation due to lack of efficacy reason was 43% significantly lesser than the control group in patients with mPCa. Rest of the outcomes were appeared to be non-significant.

CONCLUSION

Treatment with NSAA was appeared to be better efficacious with respect to PFS, TTD, and response rate with considerable adverse events when compared to the control group in patients with metastatic PCa.

Efficacy and Safety of Nilutamide in Patients with Metastatic Prostate Cancer who Underwent Orchiectomy: A Systematic Review and Metaanalysis

BACKGROUND

Prostate cancer is the sixth leading cause of death, among all cancer deaths By 2030, this burden is expected to increase with 1.7 million new cases and 499,000 new deaths. We aimed to evaluate the efficacy and safety of Nilutamide in metastatic prostate cancer (mPCa) patients who underwent orchiectomy.

METHODS

A comprehensive search was conducted in the Medline/PubMed and Cochrane Library. References from included studies and studies from clinicaltrials.gov were explored without language and date restrictions. We included only randomized controlled trials, comparing the safety and efficacy of Nilutamide in Metastatic Prostate Cancer (mPCa) patients who underwent orchiectomy with placebo. The outcomes of concerns were survival and the response of drug and safety.. Quality of the included studies was assessed using the Cochrane Risk of Bias Tool. Two authors were independently involved in the study selection, data extraction and quality assessment. Disagreements between the two reviewers were resolved by consulting a third reviewer.

RESULTS

A total of five out of 244 studies were included in meta-analysis involving1637 participants. Nilutamide group showed improved response rate (RR=1.77, 95%CI 1.46-2.14, p<0.00001), disease progression (RR=0.59, 95%CI 0.47-0.73, p<0.00001), complete response (RR=2.13, 95%CI 1.40-3.23, p=0.003) and clinical benefit (RR=1.23, 95%CI 1.13-1.34, p<0.00001) when compared to placebo; however, stable disease favored the control group (RR=0.80, 95%CI 0.68-0.94, p=0.007). In addition, patients on Nilutamide showed prolonged progression-free survival and overall survival. Nausea and vomiting were the most common adverse events reported in Nilutamide group.

CONCLUSION

Evidence suggests that patients with mPCa who underwent orchiectomy receiving Nilutamide showed significant improvement in progression-free survival and overall survival response rate and clinical benefits in comparison with the placebo group.

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

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

Prognostic factor analysis in patients with advanced prostate cancer treated by castration plus anandron or placebo: a final update

PURPOSE

Different outcome results have been published in trials comparing maximal androgen blockade (MAB) with chemical or surgical castration alone. The conflicting results could be explained by the fact that patients were included with different prognostic factors. In this new analysis of the Anandron European Study, independent prognostic factors have been evaluated in order to identify those which could influence the study outcome and the impact of the treatment.

MATERIAL AND METHODS

399 out of 457 patients recruited in this study were divided in a good or poor prognostic group depending on the presence of two or more poor prognostic factors, these were pain requiring treatment, >5 bone metastases, hydronephrosis, and alkaline phosphatase >2 ULN.

RESULTS

When expressed as a percentage, the improvement in time to progression, overall and cancer specific survival in the Anandron treated patients was identical in both groups. In absolute terms this improvement, however, was greater in the good prognostic group.

CONCLUSION

In comparison with surgical castration MAB using Anandron, in patients with metastatic prostate cancer improves the time to objective progression, overall and cancer specific survival, irrespective of certain poor prognostic factors.

Systematic review and meta-analysis of monotherapy compared with combined androgen blockade for patients with advanced prostate carcinoma

BACKGROUND

The current systematic review and meta-analysis compared monotherapy and combined androgen blockade in the treatment of men with advanced prostate carcinoma. Outcomes of interest included overall, cancer specific, and progression-free survival; time to treatment failure; adverse events; and quality of life.

METHODS

The literature search identified randomized trials comparing monotherapy (orchiectomy and luteinizing hormone-releasing hormone [LHRH] agonists) with combination therapy using orchiectomy or a LHRH agonist plus a nonsteroidal or steroidal antiandrogen. Dual independent review occurred. The meta-analysis used a random effects model.

RESULTS

Twenty-one trials compared survival after monotherapy with survival after combined androgen blockade (n = 6871 patients). The meta-analysis found no statistically significant difference in survival at 2 years between patients treated with combined androgen blockade and those treated with monotherapy (20 trials; hazard ratio [HR] = 0.970; 95% confidence interval [95% CI], 0.866-1.087). The authors determined a statistically significant difference in survival at 5 years that favored combined androgen blockade (10 trials; HR = 0.871; 95% CI, 0.805-0.942). For the subgroup of patients with a good prognosis, there was no statistically significant difference in survival. Adverse effects leading to withdrawal from therapy occurred more often with combined androgen blockade. To the authors' knowledge there is little evidence published to date comparing the effects of combined androgen blockade and monotherapy on quality of life, but the single randomized trial that adequately addressed this outcome reported an advantage for monotherapy over combined androgen blockade.

CONCLUSIONS

A thorough examination of the usefulness of combined androgen blockade must balance the modest increase in expected survival observed at 5 years against the increased risk of adverse effects and the potential for adversely affecting the patient's overall quality of life.

Combined androgen blockade with nonsteroidal antiandrogens for advanced prostate cancer: a systematic review

OBJECTIVES

Combined androgen blockade with medical or surgical castration plus a nonsteroidal antiandrogen for metastatic prostate cancer has been the subject of 20 randomized trials. The findings range from no expected increase in survival in 17 studies to an estimated 3.7 to 7 months' survival improvement noted in 3 studies. Most recently, a 1999 evidence report from the Agency for Healthcare Research and Quality and a 2000 overview from the Prostate Cancer Trialists Collaborative Group indicated that combined androgen blockade was associated with an approximately 3% to 5% increase in 5-year survival. We report herein a systematic review on combined androgen blockade performed by the Cochrane Collaborative Review Group on Prostate Diseases.

METHODS

Controlled trials that included a randomization of immediate nonsteroidal antiandrogens with castration versus castration alone for metastatic prostate cancer and provided information on survival were reviewed. Information on overall survival, toxicity, progression-free survival, cancer-specific survival, and type of nonsteroidal antiandrogen and castration therapies was abstracted by two independent reviewers.

RESULTS

Twenty trials (n = 6320 patients) were included. The pooled odds ratio (OR) for overall survival with combined androgen blockade was 1.03 (95% confidence interval [CI] 0.85 to 1.25; n = 4970 from 13 trials), 1.16 (95% CI 1.00 to 1.33; n = 5286 from 14 trials), and 1.29 (95% CI 1.11 to 1.50; n = 3550 from 7 trials) at 1, 2, and 5 years, respectively. Progression-free survival was improved at 1 year (OR = 1.38; 95% CI 1.15 to 1.67; n = 2278 from 7 trials). Cancer-specific survival was improved at 5 years (OR = 1.58; 95% CI 1.05 to 2.37; n = 781 from 2 trials). When analysis was limited to studies identified as being of high quality, the pooled OR for overall survival progressively increased but was not significant at any follow-up interval.

CONCLUSIONS

We find that there is a 5% improvement in the percentage of men surviving at 5 years (30% vs. 25%) with combined androgen blockade with nonsteroidal antiandrogens as well as improvements in progression-free survival at 1 year. Appropriate patients with metastatic prostate cancer should be informed of the potential benefits, toxicities, and out-of-pocket expenditures.

Does prolonged combined androgen blockade have survival benefits over short-term combined androgen blockade therapy?

OBJECTIVES

To explore whether less than 120 days of an antiandrogen plus a luteinizing hormone-releasing hormone agonist resulted in a different survival outcome than 120 days or more of combined treatment in patients with Stage D2 prostate cancer.

METHODS

Survival data were available from a previously published controlled trial that had evaluated the efficacy and tolerability of two antiandrogens, bicalutamide and flutamide, each combined with a monthly depot preparation of leuprolide or goserelin, in 813 patients with Stage D2 prostate cancer. Cox's proportional hazards regression model assessed the relative effects of the length of combined androgen blockade (CAB) therapy on survival. This analysis was repeated in the subset of patients who lived at least 2 years beyond the date of randomization. Data were obtained at a median follow-up of 160 weeks.

RESULTS

A survival benefit was demonstrated for patients receiving prolonged CAB therapy, with a hazard ratio of 0.275 (95% confidence interval 0.213 to 0.355, P = 0.0001) in favor of patients who received 120 days or more of CAB therapy (median survival 1035 days versus 302 days for less than 120 days of therapy). This result was confirmed in the patients who lived at least 2 years, in whom the median survival time was increased by 35%. The hazard ratio for 120 days or more of CAB therapy versus less than 120 days was 0.415 (95% confidence interval 0.246 to 0.702, P = 0.001).

CONCLUSIONS

The results of the present exploratory analysis suggest that prolonged (120 days or more) antiandrogen treatment as part of CAB therapy may result in a better survival outcome.

Maximal androgen blockade for advanced prostate cancer

OBJECTIVES

This systematic review assessed the effect of maximal androgen blockade (MAB) on survival when compared to castration (medical or surgical) alone for patients with advanced prostate cancer.

SEARCH STRATEGY

Randomized controlled trials were searched in general and specialized databases (MEDLINE, EMBASE, Cancerlit, Cochrane Library, VA Cochrane Prostate Disease register) and by reviewing bibliographies.

SELECTION CRITERIA

All published randomized trials were eligible for inclusion provided they (1) randomized men with advanced prostate cancer to receive a non-steroidal anti-androgen (NSAA) medication in addition to castration (medical or surgical) or to castration alone, and (2) reported overall survival, progression-free survival, cancer-specific survival, and/or adverse events. Eligibility was assessed by two independent reviewers.

DATA COLLECTION AND ANALYSIS

Information on patients, interventions, and outcomes were extracted by two independent reviewers using a standardized form. The main outcome measure for comparing effectiveness was overall survival at 1, 2, and 5 years. Secondary outcome measures included progression-free survival and cancer-specific survival. The relationship of specific NSAA on outcome was evaluated. Additionally, the incidence of adverse effects was measured.

MAIN RESULTS

Twenty trials enrolling 6,320 patients were included. The pooled OR for overall survival was 1.03 (95% CI:0.85 to 1.25), 1.16 (95% CI:1.00 to 1.33), and 1.29 (95% CI:1.11 to 1.50) at 1, 2, and 5 years respectively. Overall survival was only significant at 5 years. The risk difference at 5 years was 0.048 (95% CI:0.02 to 0.077) and NNT at 5 years 20.8. Progression-free survival was improved only at 1 year follow-up (OR=1.38) and cancer-free survival was improved only at 5 years (OR=1.22). Adverse events occurred more frequently in those assigned to MAB and resulted in withdrawal in 10%. Quality of life was measured in only one study favored orchiectomy alone (less diarrhea and better emotional functioning in the first 6 months).

REVIEWER'S CONCLUSIONS

MAB produces a modest overall and cancer-specific survival at 5 years but is associated with increased adverse events and reduced quality of life.

Controversies in the management of advanced prostate cancer

For advanced prostate cancer, the main hormone treatment against which other treatments are assessed is surgical castration. It is simple, safe and effective, however it is not acceptable to all patients. Medical castration by means of luteinizing hormone-releasing hormone (LH-RH) analogues such as goserelin acetate provides an alternative to surgical castration. Diethylstilboestrol, previously the only non-surgical alternative to orchidectomy, is no longer routinely used. Castration reduces serum testosterone by around 90%, but does not affect androgen biosynthesis in the adrenal glands. Addition of an anti-androgen to medical or surgical castration blocks the effect of remaining testosterone on prostate cells and is termed combined androgen blockade (CAB). CAB has now been compared with castration alone (medical and surgical) in numerous clinical trials. Some trials show advantage of CAB over castration, whereas others report no significant difference. The author favours the view that CAB has an advantage over castration. No study has reported that CAB is less effective than castration. Of the anti-androgens which are available for use in CAB, bicalutamide may be associated with a lower incidence of side-effects compared with the other non-steroidal anti-androgens and, in common with nilutamide, has the advantage of once-daily dosing. Only one study has compared anti-androgens within CAB: bicalutamide plus LH-RH analogue and flutamide plus LH-RH analogue. At 160-week follow-up, the groups were equivalent in terms of survival and time to progression. However, bicalutamide caused significantly less diarrhoea than flutamide. Withdrawal and intermittent therapy with anti-androgens extend the range of treatment options.

Androgen deprivation for prostatic carcinoma: a rationale for choosing components

Ever since prostatic carcinoma was discovered to be dependent on the hormone androgen for its proliferation, androgen deprivation has been the treatment of choice for advanced cases of prostate cancer. Originally, treatment was limited to surgical castration or estrogen therapy. However, the introduction of luteinizing hormone-releasing hormone analogues, antiandrogens, and newer treatment modalities, such as combined androgen blockade, has made choosing a treatment strategy more complex. Assuming that each modality is equally effective, emphasis should be placed on increasing patient tolerance and compliance by the use of long-acting, nontoxic treatments with simple dosing regimens and minimal side effects. This review focuses on the factors influencing the final choice of treatment strategy.

Long-term efficacy and safety of nilutamide plus castration in advanced prostate cancer, and the significance of early prostate specific antigen normalization. International Anandron Study Group

PURPOSE

We studied the long-term efficacy and tolerability of nilutamide, a nonsteroidal antiandrogen, combined with orchiectomy in patients with advanced prostate cancer.

MATERIALS AND METHODS

A large double-blind trial was done on 457 patients randomized to receive nilutamide or placebo after orchiectomy.

RESULTS

At 8.5 years of followup significant benefits were found for progression and survival in favor of patients receiving nilutamide and orchiectomy. In addition, normalized prostate specific antigen levels at 3 months from the start of therapy were predictive of good long-term outcome. Moreover, combined androgen blockade with nilutamide increased the chance of patients having normal prostate specific antigen levels at 3 months. Nilutamide was well tolerated in the long term with no increase in the incidence of drug specific adverse events.

CONCLUSIONS

With long-term followup of patients with advanced prostate cancer, the combination of nilutamide and orchiectomy has significant benefits in interval to progression and improved survival compared to orchiectomy and placebo.

Nilutamide: an antiandrogen for the treatment of prostate cancer

OBJECTIVE

To review the pharmacology, pharmacokinetics, efficacy, and adverse effects of nilutamide and to compare this agent with the currently marketed nonsteroidal antiandrogens (i.e., bicalutamide, flutamide) by critically analyzing the published literature.

DATA SOURCES

MEDLINE (1980-1995) and CANCERLIT (1991-1995) were searched for English-language publications using the terms nilutamide, bicalutamide, and flutamide alone, and either nilutamide or androgen antagonists in combination with prostatic neoplasms.

STUDY SELECTION AND DATA EXTRACTION

All articles with subject matter on nilutamide, bicalutamide, and flutamide were considered for inclusion. For studies published in more than one journal, the first publication was used unless a subsequent publication included additional or follow-up data, in which case the latter publication was cited instead.

DATA SYNTHESIS

Nilutamide was effective in combination with orchiectomy in improving responses in patients with advanced prostate cancer. However, patient survival was not improved in these trials, and improvements in bone pain did not usually result in improved performance status in these patients. The few trials of nilutamide monotherapy or nilutamide in combination with a luteinizing hormone-releasing hormone analog are too small to draw meaningful conclusions regarding its efficacy or its role in the treatment of advanced prostate cancer. No comparative trials of nilutamide with other antiandrogens and no analysis of the impact of nilutamide on patient quality of life are currently available. Nilutamide appears to produce a higher frequency of adverse effects than the other currently marketed nonsteroidal antiandrogens, bicalutamide and flutamide.

CONCLUSIONS

Nilutamide does not appear to represent a major advance in the treatment of advanced prostate cancer and appears to be somewhat inferior to both flutamide and bicalutamide with regard to adverse effects. Nilutamide should not be considered the antiandrogen of choice in the treatment of advanced prostate cancer.

Endocrine mechanisms of suppressive effect of low dose estrogen-antiandrogen treatment on androgen-dependent organs of male rats

The effects of low doses of hexestrol (Hex) (2-40 micrograms/kg bw) and flutamide (FI) (10 mg/kg bw) on some endocrine mechanisms in mature intact male rats are described in the present paper. It has been shown that each preparation, administered separately for 10 days, induced a moderate decrease in the weight of the ventral prostate (VP), anterior prostate lobe or coagulating gland (CG) and seminal vesicles (SV), in the DNA content and number of cells in the VP. 5 alpha-reductase activity was also decreased; the epithelium secretory activity of the VP was suppressed. After combined FI (10 mg/kg bw) and Hex (40 micrograms/kg bw) the following castration-like effects were observed: an abrupt fall in the weight of the accessory sexual glands, a decrease of DNA level and cell number in the VP as well as a suppression of the production of 5 alpha-reductase metabolites in this structure. Histologically, a marked degenerative changes in the VP secretory epithelium was observed; on the contrary an hyperplasia of connective and smooth muscle cells was evident. When FI alone was administered to rat, the above-mentioned changes were accompanied by a pronounced elevation of plasma bio-LH and testosterone (T) levels, also an increase of testicular delta 5-3 beta-hydroxysteroid dehydrogenase activity was observed. On the contrary, when Hex was administered alone or in combination with FI, bio-LH and T levels and enzyme activity decreased. We conclude that Hex administration in low doses, in combination with FI, could be an alternative method for a complete androgen blockade of the accessory sexual glands.

Commentary on maximal androgen blockade in prostate cancer: a theory to put into practice?

The population at risk of prostate cancer is on the increase, and so is public awareness of this disease. There has been an unresolved controversy surrounding the benefits of maximal androgen blockade (MAB) as a valid approach to treatment of non-curative prostate cancer since it was first proposed in 1945. How are we to interpret the data on MAB in order to give each patient the best advice on treatment? Studies of MAB using medical castration (luteinizing hormone-releasing hormone [LHRH] analogue plus antiandrogen) vs. LHRH analogues alone are inconclusive when viewed collectively, although the largest showed objective benefits for MAB. The remaining studies have insufficient power to show the expected effect size. Studies of MAB using surgical castration plus antiandrogen vs. surgical castration alone also gave inconsistent results, although a meta-analysis is in favor of MAB on objective criteria of response. Among trials of MAB using an LHRH analogue vs. surgical castration alone, one is positive and the remaining two are neutral for MAB. No study shows MAB to be worse than either medical or surgical castration alone. An overall meta-analysis shows a trend for benefit with MAB but is not statistically significant. The existing data have strongly suggested that there may be a particular benefit for certain subgroups of patients (including those with minimal disease) but numbers studied have been too small to allow valid conclusions. The INT 0105 trial in progress may permit firmer conclusions to be drawn on this and other questions. In the meantime one of the drawbacks to current MAB regimens is the exchange of modest clinical advantages for the side effects of nilutamide and flutamide. Given that the disease is noncurative, improved quality of life is the main goal of therapy, and excellent tolerability of treatment is fundamental to this. In a comparative trial, bicalutamide (Casodex) was more effective than flutamide (each in combination with an LHRH analogue) in terms of time to treatment failure and produced a significantly lower incidence of diarrhoea. In conclusion, the evidence supports early use of adequate hormonal treatment, and this should mean either medical or surgical castration, ideally augmented by an antiandrogen. Tolerability of the antiandrogen is a key consideration in gaining an improvement in quality of life with MAB.

Efficacy of the combination of nilutamide plus orchidectomy in patients with metastatic prostatic cancer. A meta-analysis of seven randomized double-blind trials (1056 patients)

OBJECTIVE

To review the efficacy of the combination of the anti-androgen nilutamide (Anandron) plus orchidectomy in patients with stage D prostate cancer who had received no previous treatment.

PATIENTS AND METHODS

The results of seven randomized double-blind trials were analysed. In these studies patients were followed up until progression of disease or withdrawal for other reasons. Bone pain, urinary symptoms, performance status, levels of prostatic acid phosphatase (PAP) and alkaline phosphatase (AP) were evaluated before treatment and after 1, 3, 6, 12 and 18 months of treatment. Bone scans and X-rays were taken every 6 months. The best objective response, the time of progression and the time of death were recorded. The changes from baseline in symptoms and levels of tumour markers at month six and the percentages of objective regressions in the two treatment groups were compared using the Cochran-Mantel-Haenszel test stratified by study. Peto's method was used for the analysis of time to progression and of survival.

RESULTS

Of the 1191 patients enrolled in all the original trials, 1056 were eligible. In the group of patients treated with nilutamide 50% had complete or partial regression of disease compared with 33% of those who were given a placebo (P < 0.001); bone pain and levels of PAP and AP were improved or returned to normal significantly more frequently (P < 0.01); the odds of disease progression were significantly reduced (odds ratio 0.84, P = 0.05); the odds of death from cancer and from other causes were reduced but the difference was not statistically significant.

CONCLUSIONS

The combination of nilutamide and orchidectomy has a beneficial effect on pain of metastatic origin, levels of tumour markers, the objective response of disease and the time to disease progression. This treatment combination might also improve survival.

Short-term versus long-term addition of cyproterone acetate to buserelin therapy in comparison with orchidectomy in the treatment of metastatic prostate cancer. European Organization for Research and Treatment of Cancer--Genitourinary Group

In an open, multicenter, three-armed, randomized study, we compared the effects of short-term (2 weeks) and continuous addition of the antiandrogen cyproterone acetate to the luteinizing hormone-releasing hormone agonist buserelin to those of orchidectomy in patients with advanced prostate cancer. No significant differences among the three treatment arms with respect to response rate, subjective response, time-to-progression, overall survival, and cancer deaths were observed. It was concluded that the short-term or continuous addition of cyproterone acetate to buserelin administered intranasally did not improve treatment results compared to orchidectomy only.

Multivariate analysis of plasma hormones in patients with metastatic prostate cancer receiving combined LHRH-analog and antiandrogen therapy

The following hormones, the plasma protein SHBG, and the tumor markers prostatic acid phosphatase (PAP) and prostate-specific antigen (PSA) were assayed at 18 time-points over 1 month during a double-blind randomized study in 36 stage D2 cancer patients receiving either "buserelin+placebo" or "buserelin+nilutamide (Anandron)": LH, FSH, estradiol, testosterone, dihydrotestosterone, androstenedione, 5-androstene-3,17 beta-diol, dehydroepiandrosterone and its sulfate, cortisol, 17 alpha-hydroxyprogesterone, pregnenolone, 17 alpha-hydroxypregnenolone, and 3 alpha-androstanediol glucuronide. Multivariate analysis of the treatment values (over 10,000 assays) by two complementary methods, correspondence factorial analysis (CFA) and the minimum spanning tree (MST) method, identified those variables within the pathways of androgen metabolism that were correlated over time and, in a comparison of the two treatment groups, identified the enzyme targets of nilutamide action in humans. Whereas nilutamide tended to decrease androstenedione slightly, it affected no other variables including cortisol, except for pregnenolone, 17 alpha-OH-pregnenolone, and 17 alpha-OH-progesterone, which were increased. These increases are indicative of weak inhibition of C17,20 lyase by nilutamide, but, according to the multivariate analysis, are insufficient to account for the more marked and rapid fall in PAP and PSA noted on addition of nilutamide to buserelin that must therefore be explained by another mechanism such as androgen receptor blockade by nilutamide.