Orchiectomy for advanced prostatic carcinoma. A reevaluation

Review: Mathematical Modeling of Prostate Cancer and Clinical Application

We review and synthesize key findings and limitations of mathematical models for prostate cancer, both from theoretical work and data-validated approaches, especially concerning clinical applications. Our focus is on models of prostate cancer dynamics under treatment, particularly with a view toward optimizing hormone-based treatment schedules and estimating the onset of treatment resistance under various assumptions. Population models suggest that intermittent or adaptive therapy is more beneficial to delay cancer relapse as compared to the standard continuous therapy if treatment resistance comes at a competitive cost for cancer cells. Another consensus among existing work is that the standard biomarker for cancer growth, prostate-specific antigen, may not always correlate well with cancer progression. Instead, its doubling rate appears to be a better indicator of tumor growth. Much of the existing work utilizes simple ordinary differential equations due to difficulty in collecting spatial data and due to the early success of using prostate-specific antigen in mathematical modeling. However, a shift toward more complex and realistic models is taking place, which leaves many of the theoretical and mathematical questions unexplored. Furthermore, as adaptive therapy displays better potential than existing treatment protocols, an increasing number of studies incorporate this treatment into modeling efforts. Although existing modeling work has explored and yielded useful insights on the treatment of prostate cancer, the road to clinical application is still elusive. Among the pertinent issues needed to be addressed to bridge the gap from modeling work to clinical application are (1) real-time data validation and model identification, (2) sensitivity analysis and uncertainty quantification for model prediction, and (3) optimal treatment/schedule while considering drug properties, interactions, and toxicity. To address these issues, we suggest in-depth studies on various aspects of the parameters in dynamical models such as the evolution of parameters over time. We hope this review will assist future attempts at studying prostate cancer.

Early versus deferred standard androgen suppression therapy for advanced hormone-sensitive prostate cancer

BACKGROUND

Standard androgen suppression therapy (AST) using surgical or medical castration is considered a mainstay of advanced hormone-sensitive prostate cancer treatment. AST can be initiated early when disease is asymptomatic or deferred when patients suffer symptoms of disseminated prostate cancer.

OBJECTIVES

To assess the effects of early versus deferred standard AST for advanced hormone-sensitive prostate cancer.

SEARCH METHODS

For this Cochrane Review update, we performed a comprehensive search of multiple databases (CENTRAL, MEDLINE, Embase, Web of Science; last searched November 2018) and two clinical trial registers, with no restrictions on the language of publication or publication status. We also searched bibliographies of included studies and conference proceedings (last searched January 2019).

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) with a direct comparison of early versus deferred standard AST. We excluded all other study designs. Participants included had advanced hormone-sensitive prostate cancer receiving surgical or medical castration.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies and abstracted data. The primary outcomes were time to death of any cause and serious adverse events. Secondary outcomes were time to disease progression, time to death from prostate cancer, adverse events and quality of life. We performed statistical analyses using a random-effects model and assessed the certainty of evidence according to GRADE. We performed subgroup analyses for advanced but non-metastatic disease (T2-4/N+ M0), metastatic disease (M1), and prostate-specific antigen (PSA) relapse.

MAIN RESULTS

We identified seven new RCTs since publication of the original review in 2002. In total, we included 10 RCTs.Primary outcomesEarly AST probably reduces the risk of death from any cause over time (hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.75 to 0.90; moderate-certainty evidence; 4767 participants). This corresponds to 57 fewer deaths (95% CI 80 fewer to 31 fewer) per 1000 participants at 5 years for the moderate risk group and 23 fewer deaths (95% CI 32 fewer to 13 fewer) per 1000 participants at 5 years in the low risk group. We downgraded for study limitations. Early versus deferred AST may have little or no effect on serious adverse events (risk ratio (RR) 1.05, 95% CI 0.95 to 1.16; low-certainty evidence; 10,575 participants) which corresponds to 6 more serious adverse events (6 fewer to 18 more) per 1000 participants. We downgraded the certainty of evidence for study limitations and selective reporting.Secondary outcomesEarly AST probably reduces the risk of death from prostate cancer over time (HR 0.69, 95% CI 0.57 to 0.84; moderate-certainty evidence). This corresponds to 62 fewer prostate cancer deaths per 1000 (95% CI 87 fewer to 31 fewer) at 5 years for the moderate risk group and 24 fewer death from prostate cancer (95% CI 34 fewer to 12 fewer) per 1000 men at 5 years in the low risk group. We downgraded the certainty of evidence for study limitations.Early AST may decrease the rate of skeletal events (RR 0.37, 95% CI 0.17 to 0.80; low-certainty evidence) corresponding to 23 fewer skeletal events per 1000 (95% CI 31 fewer to 7 fewer). We downgraded for study limitations and imprecision. It may also increase fatigue (RR 1.41, 95% CI 1.23 to 1.62; low-certainty evidence), corresponding to 31 more men with this complaint per 1000 (95% CI 18 more to 48 more). We downgraded for study limitations and imprecision. It may increase the risk of heart failure (RR 1.90, 95% CI 1.09 to 3.33; low-certainty evidence) corresponding to 27 more events per 1000 (95% CI 3 more to 69 more). We downgraded the certainty of evidence for study limitations and imprecision.Global quality of life is probably similar after two years as assessed with the EORTC QLQ-C30 (version 3.0) questionnaire (mean difference -1.56, 95% CI -4.50 to 1.38; moderate-certainty evidence) with higher scores reflecting better quality of life. We downgraded the certainty of evidence for study limitations.

AUTHORS' CONCLUSIONS

Early AST probably extends time to death of any cause and time to death from prostate cancer. It may slightly decrease the rate of skeletal events. Rates of serious adverse events and quality of life may be similar. It may increase fatigue and may increase the risk of heart failure. Better quality trials would be particularly important to better understand the outcomes related to possible treatment-related harm, for which we only found low-certainty evidence.

A patient-level data meta-analysis of standard-of-care treatments from eight prostate cancer clinical trials

Open clinical trial data offer many opportunities for the scientific community to independently verify published results, evaluate new hypotheses and conduct meta-analyses. These data provide valuable opportunities for scientific advances in medical research. Herein we present the comparative meta-analysis of different standard of care treatments from newly available comparator arm data from several prostate cancer clinical trials. Comparison of survival rates following treatment with mitoxantrone or docetaxel in combination with prednisone as well as prednisone alone, validated the previously demonstrated superiority of treatment with docetaxel. Additionally, comparison of four testosterone suppression treatments in hormone-refractory prostate cancer revealed that subjects who had undergone surgical castration had significantly lower survival rates than those treated with LHRH, anti-androgen or LHRH plus anti-androgen, suggesting that this treatment option is less optimal. This study illustrates how the use of patient-level clinical trial data enables meta-analyses that can provide new insights into clinical outcomes of standard of care treatments and thus, once validated, has the potential to help optimize healthcare delivery.

Sexuality and Intimacy After Definitive Treatment and Subsequent Androgen Deprivation Therapy for Prostate Cancer

There are more than 2 million prostate cancer survivors in the United States. Primary therapy with surgery or radiation results in permanent changes in sexual function. More than half of these men are subsequently treated with androgen deprivation therapy (ADT) at some point. The addition of ADT further compromises sexuality, intimacy, and a couple's relationship. This review will highlight the challenges faced by patients and couples and reveal the tremendous need for better education of physicians, patients, and couples as well as for more research in sexuality and intimacy with the goal of improving quality of life for this large population of survivors. Suggestions for clinicians to better help patients and their partners regarding sexuality and intimacy are offered.

Progress in understanding androgen-independent prostate cancer (AIPC): a review of potential endocrine-mediated mechanisms

This review is triggered by recent developments that offer new explanations for the mechanism of progression of prostate cancer to androgen independence. Established and hypothetical mechanisms, which have been described in the past, are put into perspective with recent progress in the field. A total of seven mechanisms can be identified that relate to progression to androgen independence. Five of those are dependent on the androgen receptor, which is present or over-expressed in androgen-independent prostate cancer tissue. Probably due to selective pressure, AIPC cells have the capability to escape from the effect of castration and antiandrogens; exclusion of the androgen receptor activity by inhibition of dimerisation or inhibition of DNA binding seem to be the logical next steps. Although androgen levels and androgen synthesis are suppressed in prostatic tissues during the phase of response to endocrine treatment, androgen levels and, specifically, 5-alpha-dihydrotestosterone (DHT) were elevated in tissues derived from metastases of AIPC. In addition, all enzymes needed to synthesise androgens from the level of pregnenolone on are present or over-expressed in such tissue. This offers new potential for treatment.

The natural history of men treated with deferred androgen deprivation therapy in whom metastatic prostate cancer developed following radical prostatectomy

PURPOSE

We report on the natural history and factors influencing the prognosis of a cohort of hormone naïve, prostate specific antigen era patients in whom metastatic prostate cancer developed after radical prostatectomy who were followed closely and treated with deferred androgen deprivation therapy at the time of metastasis.

MATERIALS AND METHODS

A total of 3,096 men underwent radical prostatectomy performed by a single surgeon at Johns Hopkins Hospital between 1987 and 2005. Of these men 422 had prostate specific antigen failure. Distant metastasis developed in 123 patients, of whom 91 with complete data formed the study cohort initially treated during the prostate specific antigen era (1987 to 2005) and receiving androgen deprivation therapy after documented metastasis. A total of 41 men died of prostate cancer. Median survival times were estimated by Kaplan-Meier analysis. Prognostic impact was estimated as the hazard ratio derived from the Cox proportional hazards model.

RESULTS

Median followup from radical prostatectomy was 120 months (range 24 to 216). Kaplan-Meier median (range) times to failure were 24 months (12 to 144) from radical prostatectomy to prostate specific antigen failure, 36 months (0 to 132) from prostate specific antigen failure to metastasis, 84 months (12 to 180) from metastasis to death and 168 months (24 to 216) from radical prostatectomy to death. Statistically significant univariate risk factors for prostate cancer specific mortality at the time of metastasis were pain at diagnosis of metastases (p = 0.002), time from radical prostatectomy to metastasis (p = 0.024) and prostate specific antigen doubling time less than 3 months during the 24 months before metastasis (p = 0.016). Multivariable analysis demonstrated independent predictors of prostate cancer specific mortality at the time of metastasis, namely pain (HR 3.5, p = 0.003) and prostate specific antigen doubling time less than 3 months (HR 3.4, p = 0.017).

CONCLUSIONS

Men treated with deferred androgen deprivation therapy for the development of metastasis after radical prostatectomy may have a long life span, 169 months after radical prostatectomy (range 24 to 216). The presence of pain and short prostate specific antigen doubling time predicted an unfavorable outcome.

Prostate cancer screening strategies with re-screening interval determined by individual baseline prostate-specific antigen values are cost-effective

AIMS

To determine whether prostate cancer screening strategies with re-screening interval determined by individual baseline prostate-specific antigen values are cost-effective.

METHODS

Based on the results of an actual contemporary screening program, we established Markov decision analytic models of prostate cancer screening with personalized re-screening interval strategies using cutoff baseline PSA levels for biennial screening as well as a model of uniformly annual or biennial screening. These strategies were compared in terms of cumulative incidence of early cancer and cost-effectiveness.

RESULTS

Early cancer detection rates were similar among all strategies. Personalized strategies were more cost-effective compared to uniform screening strategies. If all participants with negative PSA results uniformly omit annual screening, it would be more costly but less effective (dominated). Contrary, annual screening for all participants would cost too much. These results were robust throughout sensitivity analysis incorporating every assumption in the models.

CONCLUSIONS

This study adds important evidence that personalized rescreening strategies based on individual baseline PSA have advantages of cost-effectiveness against conventional uniform strategies.

Primary hormone therapy for locally advanced prostate cancer

Locally advanced prostate cancer is a treatment dilemma. As with prostate cancer in general, there is no clear evidence that aggressive intervention (ie, surgery or radiation) is superior to noninvasive interventions (eg, delayed treatment or androgen ablation). Because patients with locally advanced prostate cancer have a high risk of local and systemic recurrence, there is some argument to proceed with androgen ablation as the sole modality of treatment. The data using this approach are limited, but an understanding of the degree and duration of response is helpful in selecting patients for primary androgen ablation.

Clinical strategies in the management of biochemical recurrence after radical prostatectomy

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

Patients' preferences for the management of non-metastatic prostate cancer: discrete choice experiment

OBJECTIVE

To establish which attributes of conservative treatments for prostate cancer are most important to men.

DESIGN

Discrete choice experiment.

SETTING

Two London hospitals.

PARTICIPANTS

129 men with non-metastatic prostate cancer, mean age 70 years; 69 of 118 (58%) with T stage 1 or 2 cancer at diagnosis.

MAIN OUTCOME MEASURES

Men's preferences for, and trade-offs between, the attributes of diarrhoea, hot flushes, ability to maintain an erection, breast swelling or tenderness, physical energy, sex drive, life expectancy, and out of pocket expenses.

RESULTS

The men's responses to changes in attributes were all statistically significant. When asked to assume a starting life expectancy of five years, the men were willing to make trade-offs between life expectancy and side effects. On average, they were most willing to give up life expectancy to avoid limitations in physical energy (mean three months) and least willing to trade life expectancy to avoid hot flushes (mean 0.6 months to move from a moderate to mild level or from mild to none).

CONCLUSIONS

Men with prostate cancer are willing to participate in a relatively complex exercise that weighs up the advantages and disadvantages of various conservative treatments for their condition. They were willing to trade off some life expectancy to be relieved of the burden of troublesome side effects such as limitations in physical energy.

Hormonal therapy options for patients with a rising prostate-specific antigen level after primary treatment for prostate cancer

At this time, many treatment options exist for primary androgen-deprivation therapy. "Standard" options with long-term results on outcome include orchiectomy, monotherapy with a luteinizing hormone-releasing hormone (LHRH) agonist, and combined androgen blockade using an LHRH agonist and antiandrogen. All treatments are associated with some morbidity related to the reduction of circulating testosterone. For this reason, "alternative" regimens are under active study to determine whether equal outcomes can be achieved with lesser toxicity.

Phase II trial of oral cyclophosphamide, prednisone, and diethylstilbestrol for androgen-independent prostate carcinoma

BACKGROUND

The authors evaluated the combination of oral cyclophosphamide, oral prednisone, and diethylstilbestrol (DES) in patients with androgen-independent prostate carcinoma (AIPC).

METHODS

Thirty-seven patients with prostate carcinoma refractory to androgen ablation who had undergone antiandrogen withdrawal (if previously treated with an antiandrogen) were enrolled in the current study. They were treated with oral cyclophosphamide 100 mg per day on Days 1-20, prednisone 10 mg per day continuously, and DES 1 mg continuously, on a 30-day cycle. Warfarin 1 mg per day was given as prophylaxis for thrombosis. Patient levels of prostate-specific antigen (PSA) were monitored on a monthly basis, with imaging studies every 3 months. Patients continued to receive therapy until disease progression or the occurrence of significant toxicity. The effect of therapy on the patient's quality of life was assessed using the Functional Assessment of Cancer Therapy-Prostate.

RESULTS

Thirty-six patients were evaluable for response. Of the 36 patients, 15 (42%) had a 50% or greater decline in PSA levels from pretreatment levels and 1 patient (6%) with measurable disease had a partial response to therapy. The median duration of response was 4.5 months (range, 4-18 months). The overall median survival period was 16.4 months. The treatment was well tolerated, with only three patients removed from the study for toxicities associated with treatment. One patient, who had been treated for more than 24 months, developed acute leukemia. Quality of life evaluation in 17 patients showed a significant improvement in responders, whereas nonresponders had no deterioration while receiving therapy.

CONCLUSIONS

Cyclophosphamide, prednisone, and DES represent a well tolerated, low-cost combination therapy with significant activity in the treatment of patients with AIPC.

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.

Controversies in the systemic management of patients with evidence of biochemical failure following radical prostatectomy

The management of patients with evidence of a detectable prostate-specific antigen (PSA) following prostatectomy is an increasingly common and difficult issue for patients and clinicians alike. In the setting in which biochemical failure is believed representative of early systemic failure, therapeutic options primarily involve the use of hormonal therapy. Extrapolating results of early vs. delayed hormonal therapy from studies of patients with more advanced prostate cancer is problematic. Antiandrogen monotherapy and intermittent androgen deprivation are increasingly popular approaches, although their ultimate utility remains unproven. This patient subset is an optimal one in which to conduct clinical trials to both define the role of hormonal therapy and to investigate novel, non-hormonal approaches. The most appropriate therapeutic intervention for patients with evidence of biochemical failure following radical prostatectomy remains undefined.

Melatonin and prostate cancer cell proliferation: interplay with castration, epidermal growth factor, and androgen sensitivity

BACKGROUND

Potential modulatory effects of melatonin on the proliferation of androgen-sensitive LNCaP and androgen-insensitive PC-3 and DU 145 prostate cancer cells were reported recently. In this study, we investigated the effects of combined melatonin and castration on LNCaP tumor growth in vivo, the interactions between melatonin and epidermal growth factor (EGF) on LNCaP cell proliferation, and melatonin actions on the proliferation of PC-3 and DU 145 cells.

METHODS

Tumor development and growth in castrated nude mice inoculated with LNCaP cells or in intact animals inoculated with DU 145 cells, with or without daily melatonin treatment, were monitored by observation and caliper measurement. MT(1) receptor expression in native or transfected prostate cancer cell lines was examined by immunocytochemistry or 2-[(125)I]iodomelatonin binding. Cyclin D1 expression in LNCaP cells was assessed by Western blotting, and cell proliferation was measured by thymidine incorporation and/or cell count.

RESULTS

Melatonin treatment was associated with further decreases in LNCaP tumor incidence and growth rate in castrated nude mice. Melatonin and 2-iodomelatonin (a melatonin receptor agonist) attenuated EGF-stimulated increases in LNCaP cell proliferation and cyclin D1 levels. Melatonin had no effect on the proliferation or growth of MT(1) receptor-expressing DU 145 cells, and of PC-3 cells in which MT(1) receptor protein was undetectable. The proliferation of transfected PC-3 cells expressing MT(1) receptor was unaffected by 2-iodomelatonin.

CONCLUSION

Together with previous data, the present results indicate synergistic action of melatonin and castration in inhibiting the growth of androgen-sensitive LNCaP tumor. Androgen-sensitive prostate cancer cell proliferation may be modulated by opposite changes in cyclin D1 levels induced by activated MT(1) and EGF receptors. In androgen-insensitive prostate cancer cells, MT(1) receptor-mediated signal transduction may become defective not only through changes in membrane receptor protein expression and/or functions, but also by means of alterations in downstream postreceptor signaling events.

Expression profile of differentially-regulated genes during progression of androgen-independent growth in human prostate cancer cells

Because of the heterogeneous nature of prostate cancer, identifying the molecular mechanisms involved during the transition from an androgen-sensitive to an androgen-independent phenotype is very complex. An LNCaP cell model that recapitulates prostate cancer progression, comprising early passage androgen-sensitive (LNCaP-C33) and late passage androgen-independent (LNCaP-C81) phenotypes, would help to provide a better understanding of such molecular events. In this study, we examined the genes expressed by LNCaP-C33 and LNCaP-C81 cells using cDNA microarrays containing 1176 known genes. This analysis demonstrated that 34 genes are up-regulated and eight genes are down-regulated in androgen-independent cells. Northern blot analysis confirmed the differences identified by microarrays on several candidate genes, including c-MYC, c-MYC purine-binding transcription factor (PuF), macrophage migration inhibitory factor (MIF), macrophage inhibitory cytokine-1 (MIC-1), lactate dehydrogenase-A (LDH-A), guanine nucleotide-binding protein Gi, alpha-1 subunit (NBP), cyclin dependent kinase-2 (CDK-2), prostate-specific membrane antigen (PSM), cyclin H (CCNH), 60S ribosomal protein L10 (RPL10), 60S ribosomal protein L32 (RPL32), and 40S ribosomal protein S16 (RPS16). These differentially-regulated genes are correlated with progression of human prostate cancer and may be of therapeutic relevance as well as an aid in understanding the molecular genetic events involved in the development of this disease's hormone-refractory behavior.

Inhibition of in vivo proliferation of MDA-PCa-2b human prostate cancer by a targeted cytotoxic analog of luteinizing hormone-releasing hormone AN-207

The efficacy of therapy with targeted cytotoxic luteinizing hormone-releasing hormone (LHRH) analog AN-207 consisting of superactive doxorubicin derivative AN-201 linked to carrier [D-Lys(6)]LH-RH was evaluated in vivo in nude mice bearing xenografts of MDA-PCa-2b prostate cancer line. AN-207 was administered intravenously (i.v.) at 200 nmol/kg on day 1 and at 150 nmol/kg on day 14. After 4 weeks of treatment with AN-207, tumor growth was inhibited as shown by a 63% (P<0.01) decrease in tumor volume and a 55% (P<0.05) reduction in tumor weight, compared with controls. None of the animals died after administration of AN-207 at the total dose of 350 nmol/kg, and at the end of the experiment the body weights of mice given AN-207 did not differ significantly from controls. A single injection of cytotoxic radical AN-201 at 200 nmol/kg resulted in 43% mortality. In the surviving mice, AN-201 caused a 50% inhibition in tumor volume and a 27% reduction in tumor weight, which were non-significant, as compared to the controls. After 4 weeks, serum prostate-specific antigen concentrations in mice treated with AN-207 were 65% lower than those in controls (P<0.05), while in animals given AN-201 the reduction in serum prostate-specific antigen was only 40% (NS). The expression of mRNA for LHRH receptors was detected by reverse transcriptase polymerase chain reaction (RT-PCR) in MDA-PCa-2b tumors. The present study indicates that chemotherapy targeted to LHRH receptors on tumors inhibits growth of MDA-PCa-2B prostate cancers representative of human carcinoma disseminated to the bone and progressing despite androgen withdrawal.

A structured debate: immediate versus deferred androgen suppression in prostate cancer-evidence for deferred treatment

PURPOSE

We present a structured debate supporting the premise that immediate hormonal intervention has not been conclusively shown to provide a survival advantage in the management of advanced prostate cancer.

MATERIALS AND METHODS

The literature emphasizing randomized trials was reviewed. Recommendations are based solely on a demonstrated advantage in survival.

RESULTS

In patients with stage Tx Nx Mo or MI disease who did not receive other primary therapy there is no demonstrated survival advantage to immediate hormonal therapy. In men with positive lymph nodes who underwent radical prostatectomy a relatively small study showed a survival advantage in favor of immediate hormonal treatment compared to deferred treatment. This study did not reach the projected accrual of 240 patients and results have not been supported by other trials. In men with stages T2-4 Nx Mx disease who underwent primary treatment with radiotherapy a survival advantage for early hormonal therapy is primarily limited to high risk subgroups. In patients with biochemical relapse following primary treatment there are no trials.

CONCLUSIONS

Because hormonal therapy is associated with the development of irreversible resistance in virtually all patients, it does not cure, there is usually a long interval from first prostate specific antigen elevation to the development of metastatic disease, and hormonal therapy has profound side effects and is expensive, delayed treatment is recommended in men with biochemical relapse following surgery or radiotherapy. Patients should be strongly encouraged to enter clinical trials to answer this question.

Single-therapy androgen suppression in men with advanced prostate cancer: a systematic review and meta-analysis

PURPOSE

To compare luteinizing hormone-releasing hormone (LHRH) agonists with orchiectomy or diethylstilbestrol, and to compare antiandrogens with any of these three alternatives.

DATA SOURCES

A search of the MEDLINE, Cancerlit, EMBASE, and Cochrane Library databases from 1966 to March 1998 and Current Contents to 24 August 1998 for articles comparing the outcomes of the specified treatments. The search was limited to studies on prostatic neoplasms in humans. Total yield was 1477 studies.

STUDY SELECTION

Reports of efficacy outcomes were limited to randomized, controlled trials. Twenty-four trials involving more than 6600 patients, phase II studies that reported on withdrawals from therapy (the most reliable indicator of adverse effects), and all studies reporting on quality of life were abstracted.

DATA EXTRACTION

Two independent reviewers abstracted each article by following a prospectively designed protocol. The meta-analysis combined data on 2-year overall survival by using a random-effects model and; reported results as a hazard ratio relative to orchiectomy.

DATA SYNTHESIS

Ten trials of LHRH agonists involving 1908 patients reported no significant difference in overall survival. The hazard ratio showed LHRH agonists to be essentially equivalent to orchiectomy (hazard ratio, 1.1262 [corrected] [95% CI, 0.915 to 1.386]). There was no evidence of difference in overall survival among the LHRH agonists, although CIs were wider for leuprolide (hazard ratio, 1.0994 [CI, 0.207 to 5.835]) and buserelin (hazard ratio, 1.1315 [CI, 0.533 to 2.404]) than for goserelin (hazard ratio, 1.1172 [CI, 0.898 to 1.390]). Evidence from 8 trials involving 2717 patients suggests that nonsteroidal antiandrogens were associated with lower overall survival. The CI for the hazard ratio approached statistical significance (hazard ratio, 1.2158 [CI, 0.988 to 1.496]). Treatment withdrawals were less frequent with LHRH agonists (0% to 4%) than with nonsteroidal antiandrogens (4% to 10%).

CONCLUSIONS

Survival after therapy with an LHRH agonist was equivalent to that after orchiectomy. No evidence shows a difference in effectiveness among the LHRH agonists. Survival rates may be somewhat lower if a nonsteroidal antiandrogen is used as monotherapy.

Steroid hormones and cancer: IV. Prostate cancer

Over many years, a great deal of attention has focused on the growth regulatory effects of androgens in prostate cells. This, has also prompted widespread interest in the role of these steroid hormones in prostate cancer pathogenesis. Even so, no-one has so far been able to identify the exact relationship between androgenic hormone levels and the risk of these diseases though differences in hormonal patterns amongst racial ethnic groups has been reported to reflect diversities in prostate cancer incidence. One of the difficulties stems from the fact that serum hormone levels do not reflect the changes observed in prostate tissue androgen concentrations as the normal prostate progresses to a disease state. In this article efforts will be directed towards understanding some of the intra-prostate-specific mechanisms responsible for activating and/or repressing the androgen-dependent gene network associated with the gradual transition to a hormone refractive neoplastic state.

Genetic changes associated with the acquisition of androgen-independent growth, tumorigenicity and metastatic potential in a prostate cancer model

Genetic changes underlying the progression of human prostate cancer are incompletely understood. Recently, an experimental model system that resembles human prostate cancer progression was developed based on the serial passage of an androgen-responsive, non-tumorigenic LNCaP prostate cancer cell line into athymic castrated mice. Six different sublines, derived after one, two or three rounds of in vivo passage, sequentially acquired androgen independence and tumorigenicity as well as metastatic capacity. Here, we used comparative genomic hybridization (CGH) and locus-specific fluorescence in situ hybridization (FISH) analysis to search for genetic changes that may underlie the phenotypic progression events in this model system. Six genetic aberrations were seen by CGH in the parental LNCaP cell line. The derivative sublines shared virtually all these changes, indicating a common clonal origin, but also contained 3-7 additional genetic changes. Gain of the 13q12-q13 chromosomal region as well as losses of 4, 6q24-qter, 20p and 21q were associated with androgen independence and tumorigenicity with additional changes correlating with metastasis. In conclusion, an accumulation of genetic changes correlates with tumour progression in this experimental in vivo model of prostate cancer progression. It is possible that the specific chromosomal aberrations involved in this model system may provide clues to the location of genes involved in human prostate cancer progression and metastasis.

Clinical study on prognosis of metastatic prostate cancer based on extent of disease on pretreatment bone scintigraphy

The pretreatment bone scintigrams of 58 patients with prostate cancer with bone metastasis were reviewed and the prognostic value of the initial extent of bone involvement was compared with that of other pretreatment characteristics. The extent of bone metastasis revealed by the scan was related to survival. The serum level of alkaline phosphatase at pretreatment and pathological grade also had some predictive value. Although the pathological grade of primary tumours was related to prognosis, the survival of patients with the same histological grade differed according to the initial extent of disease; patients with extensive disease along with raised serum alkaline phosphatase (twice or more as high as the cut-off value) had poorer prognosis than did those with lower alkaline phosphatase or smaller extent of disease. The extent of bone involvement in combination with serum alkaline phosphatase level therefore apparently has higher prognostic value than does disease extent alone.

Histopathological grading and DNA ploidy as prognostic markers in metastatic prostatic cancer

The present study compares the prognostic potential of tumour grade and DNA ploidy status in patients with advanced-stage prostatic cancer. Two outcome groups were selected on the basis of time to progression and survival after orchiectomy. A poor-outcome group consisted of 32 therapy-resistant patients who experienced disease progression during the first year after orchiectomy and subsequently death due to prostatic cancer during the following year. A good-outcome group consisted of 27 therapy-responsive patients who showed disease regression and no signs of progression during a 3 year follow-up. The primary tumours were graded twice according to WHO and Gleason classification systems by two pathologists. Final agreement between the pathologists was obtained after a consensus meeting. The analysis revealed no prognostic importance of the two histological classification systems (P = 0.62 and P = 0.70) and disclosed weak inter- and intra-observer reproducibility (kappa < 0.70). DNA ploidy analyses were performed by image cytometry on formalin-fixed, paraffin-embedded samples of the primary tumours. Overall, 48% of the tumours were diploid, 20% tetraploid and 32% anueploid. DNA ploidy status did not discriminate between the two outcome groups (P = 0.46). Histological grade and DNA ploidy showed no prognostic importance in patients with prostatic cancer and skeletal metastases.

Nuclear shape and prognosis following orchiectomy in stage D2 prostate cancer

In this study, we have examined whether tumor grade and morphometric nuclear features can predict the outcome of treatment by orchiectomy in patients with stage D2 prostate cancer. Two outcome groups based on duration of survival postorchiectomy were examined, a bad outcome group of 63 patients who died from prostate cancer within 12 months and a good outcome group of 34 patients who survived beyond 5 years. Tumors were histologically classified as well (17%), moderate (17%), or poorly differentiated (66%). Tumor grade and patient outcome were significantly associated (Mann-Whitney test; P < 0.005), with 76% of poorly differentiated tumors in the bad outcome group, and 65% of well-differentiated tumors in the good outcome group. Using discriminant function analysis, tumor grade correctly predicted outcome in 70% of cases. A statistically significant difference was also detected in nuclear shape values between the two outcome groups (P < 0.05) and histological grades (P < 0.05). Using discriminant function analysis, 51% of cases were correctly classified into outcome groups using nuclear shape factors, a figure which rose to 65% when all nuclear morphometric features were used. This demonstrates that nuclear morphometric features are of no clinical value in predicting the outcome of treatment in stage D2 disease. Furthermore, these evaluations cannot select patients who might be spared orchiectomy on the basis of a predicted poor response. However, nuclear shape and variance measurements of benign glandular epithelial cells within cancerous prostates were significantly different from those of malignant cells (P < 0.005). We conclude that, while video image analysis of prostatic nuclear shape can reliably discriminate between benign and malignant cells, nuclear morphometric features are of minimal prognostic value in men with stage D2 prostate cancer treated by androgen ablation.

Neoadjuvant hormonal therapy and radical prostatectomy for clinical stage C carcinoma of the prostate

OBJECTIVE

To determine whether hormonal therapy prior to radical prostatectomy (neoadjuvant hormonal therapy) leads to improved results in patients with stage C prostate cancer.

PATIENTS AND METHODS

Thirty patients received neoadjuvant hormonal therapy for stage C carcinoma of the prostate. Eighteen patients who responded to treatment subsequently underwent extirpative surgery.

RESULTS

Fourteen of the 30 patients (47%) were diagnosed as being downstaged to clinical stage B disease following therapy. No major complications occurred. Pathology staging revealed only three patients (10%) to have organ-confined disease after radical prostatectomy.

CONCLUSIONS

Neoadjuvant hormonal therapy prior to radical prostatectomy offers little probability of rendering patients with clinical stage C carcinoma of the prostate free of disease. Further investigation of the efficacy of this treatment should be accomplished in randomized trials.

Gleason's histologic grading as clinical prognostic marker in patients with advanced prostatic carcinoma

We have found that the Gleason's histologic grading system is a good clinical marker to predict long-term response and prognosis in symptomatic Stage D-2 adenocarcinoma of the prostate. In this retrospective study, 56 cases were reviewed and correlated with bone scan, acid phosphatase, and symptomatology following bilateral orchiectomy.

[Problems and principles of hormone therapy of advanced prostate cancer]

The availability of hormones with few side effects has enlarged the indication for their use: In the presence of metastases, primary endocrine treatment which includes orchiectomy as standard therapy is employed with palliative intent. Adjuvant endocrine treatment is given after radical prostatectomy when positive margins or lymph nodes were present. A salvage endocrine treatment is administered if the primary tumor persists after radiotherapy or recurred after prostatectomy. The term diagnostic hormone treatment is misleading and should not be used. A secondary hormone application is supported by the observation that allaged hormone resistant tumor progressed after testosterone injection. The problem of early versus delayed endocrine therapy is unsolved, however, it is conceivable that the latter therapy is confronted with a larger tumor burden. The principle of endocrine treatment is properly described as means suppressing the androgenic stimuli. There are 5 different routes of androgen deprivation, among which the antiandrogens and LH RH analogs have the highest priority. Phase III-studies are under way to clarify their efficacy.

The role of endocrine therapy in prostatic cancer

When judged by randomized clinical trial, current endocrine therapies offer symptomatic relief to prostatic cancer patients for an average period of 1-2 years following initiation of therapy. Medical castration with LHRH analogues is a safe and effective way of achieving 'castrate' levels of circulating androgens without the undesirable aspects of surgery. While there is some evidence for the value of combined therapies using these agents in combination with anti-androgens for 'total androgen blockade' in some patients, overall this approach has not been shown to offer advantages over castration, either surgical or medical, alone in controlled trials. Secondary endocrine therapy does not offer convincing objective response rates, suggesting that disease progression is independent of androgens.

Hormonal therapy for prostate cancer

Since the demonstration in 1941 by Huggins and Hodges that prostatic cancers are androgen dependent, hormonal treatment by androgen ablation has been the principal treatment for patients with advanced adenocarcinoma of the prostate. Although not able to permanently and totally eradicate every cancer cell since prostate cancer cells are quite heterogeneous in their sensitivity to androgens, hormonal therapy can produce dramatic subjective improvement as well as objective remissions. This results in an improved quality of survival and for patients with metastatic adenocarcinoma, endocrine therapy does reduce the death rate from cancer, and if death from other concurrent illness is controlled, there is an absolute increase in survival. At present, a variety of strategies are available for ablation of testicular and adrenal androgens, but results are not clinically significantly better than orchiectomy.

Single-drug parenteral estrogen treatment in prostatic cancer: a study of two maintenance-dose regimens

Treatment of 17 patients with prostatic cancer with 320 mg polyestradiol phosphate (PEP) as intramuscular injections every fourth week suppressed serum testosterone (T) values to orchidectomy levels within 1 month, and serum estradiol-17 beta (E2) rose to a mean level of 2,456 pmol/liter after 6 months. Following 6 months of treatment, the PEP dose was reduced to 80 mg/4 weeks in 9 and 160 mg/4 weeks in eight patients. Mean T levels, increased significantly after dose reduction in both groups and were above the upper orchidectomy limit at 1 month after dose reduction in the 80 mg group. Mean T levels, however, remained below this level at 5 months in the 160 mg group. Dose reduction caused a rise in gonadotropin levels in the 80 mg but not in the 160 mg group. While 320 mg/4 weeks may be a suitable initial dosage, doses less than or equal to 160 mg/4 weeks are insufficient as maintenance dosages if orchidectomy values of T are required.

Treatment of metastatic prostate cancer. Factors that influence treatment selection and methods to increase acceptance of orchiectomy

Orchiectomy is the preferred method for treating patients with metastatic adenocarcinoma of the prostate (MAP) because it is safer and more reliable than estrogen therapy. Nonetheless, a survey of Northern California urologists showed that 57 percent of their patients with MAP were treated with diethylstilbestrol (DES) rather than orchiectomy. Factors which determined treatment selection include the physician's belief that estrogen therapy was either equally (35%) or more (22%) effective than orchiectomy and the patients' rejection of orchiectomy even if it were recommended to them (20-30%). The survey also showed that previous attempts to increase the acceptability of orchiectomy by performing a subcapsular procedure have failed because urologists do not believe the procedure is effective (45%), or that subcapsular orchiectomy provides a satisfactory cosmetic result (20%). Recent laboratory and clinical investigations have shown that complete and subcapsular orchiectomy were equally effective in reducing serum testosterone. Patient acceptance of subcapsular orchiectomy may be increased by utilizing the term testicular curettage, which does not imply castration, to describe the procedure and by implantation of intracapsular testicular prostheses to restore normal testicular anatomy after the testicles' hormone-producing tissue has been removed.

Carcinoma of the prostate: pathology, staging, and treatment

Prostate cancer is the most common malignancy affecting American men over the age of 50. Its incidence increases with each decade. It is usually discovered by rectal examination performed during physical examination or incidentally found on histologic sections of a prostate removed to alleviate urinary obstructive symptoms. About 50% of patients have clinically localized disease at presentation. The majority of prostate cancers grow slowly, metastasize late, and are not the primary cause of death. Before recommending treatment to a patient with prostate cancer, the treating physician should assess the extent of malignancy and determine which therapy, if any, would favorably influence the course of disease with the least influence on the general quality of life. Patients with disease limited to the prostate are offered curative therapy with either radical prostatectomy or radiation therapy. Those with locally extensive disease are treated with external beam irradiation or with androgen ablation. Metastatic disease is treated by androgen ablation. Chemotherapy is reserved for those patients who fail hormonal treatment.

The value of testosterone deprivation in stage D1 carcinoma of the prostate

The question of whether hormonal manipulation is effective in the treatment of stage D1 carcinoma of the prostate has yet to be determined conclusively. To study this question a retrospective review was conducted of 68 patients with stage D1 disease. Of the patients 22 underwent immediate orchiectomy, 24 delayed orchiectomy and 11 exogenous antiandrogen treatment (8 immediate and 3 delayed treatment), and 11 had no androgen deprivation. The patients were placed into 2 groups consisting of those receiving immediate hormonal deprivation (30) and those having treatment at the time of bone metastasis or who are as yet untreated (38). The minimum followup was 60 months. The median interval to progression to bone metastasis was 43 months in the delayed treatment group compared to 100 months in the immediate hormonal deprivation group. This difference was statistically significant (p equals 0.0087). Likewise, the median period from diagnosis to death was 90 months in the delayed treatment group and 150 months in the immediate treatment group. This difference was not significant (p equals 0.1110). Thus, orchiectomy or adequate androgen deprivation from our data significantly prolongs the interval to bone metastasis in patients with metastatic prostate cancer limited to the pelvic lymph nodes. The apparent increased length of survival of the immediate treatment group lacks statistical confirmation.

Stratification of patients with metastatic prostate cancer based on extent of disease on initial bone scan

Most patients with metastatic prostate cancer will have metastasis to bone. Such patients are best monitored by serial radionuclide bone scans. One hundred sixty six men with bone metastasis from prostate cancer who received androgen deprivation therapy had their pretreatment bone scans reviewed using a semiquantitative grading system based upon the extent of disease (EOD) observed on the scan. The EOD on the scan correlated with survival. The 2-year survival rates for EOD I to IV were 94%, 74%, 68%, and 40%, respectively. The survival of patients in categories EOD I and IV significantly differed from the other categories. Men with metastatic prostate cancer entered into trials designed to evaluate the impact of treatment on survival should be stratified based upon the EOD on the bone scan. This analysis also indicates that patients in the EOD IV category have a particularly poor prognosis and may be candidates for alternative treatments.

Transplantable human prostatic carcinoma (PC-82) in athymic nude mice. III. Effects of estrogens on the growth of the tumor tissue

The transplantable human prostatic tumor model (PC-82) in nude mice was used to evaluate the indirect and possibly direct effects of estrogens on the growth of prostatic tumor tissue. High (pharmalogical) doses of plasma estradiol (E2) were achieved in tumor-bearing mice by using E2-containing Silastic implants of different lengths. In comparison with the situation in men, in mice much higher concentrations of circulating E2 (exceeding 3 nmol/liter) were necessary to attain (near)-castrate levels of plasma testosterone (T). Treatment of tumor-bearing mice with a high dose of E2 resulted in tumor growth arrest and a subsequent decline of the tumor volume, which equals the effects of castration. No evidence was found that either of the two doses of E2 applied had any additive inhibitory effect on tumor growth when compared to castration alone. It was inferred from these findings that in the PC-82 tumor model, estrogens, rather than having a direct effect on the tumor tissue, mainly act indirectly by their suppressive effect on T secretion in the host animal. A different and unexpected result was obtained in castrated tumor-bearing mice treated with a combination of E2 and T. With both doses of E2 this type of treatment led to a smaller increase of the tumor volume compared with mice receiving T only, the result of the high dose being statistically significant. This antagonistic effect of the two steroids on the PC-82 tissue was paradoxically associated with a sharp increase of nuclear androgen receptor levels and a higher concentration of dihydrotestosterone in the tumor tissue. Plasma and tissue concentrations of T appeared to be unaltered. The present study of the PC-82 prostate tumor shows that only by careful monitoring of plasma steroid levels in tumor-bearing mice can conclusions about the effectiveness of hormonal treatment regimens, such as estrogen therapy, be drawn.

Combined hormone-chemotherapy for metastatic prostatic carcinoma. Eleven-year follow-up

Thirty-six patients with histology-proved Stage D2 carcinoma of the prostate were treated with a combination of bilateral orchiectomy, diethylstilbestrol 3 mg/day, and chemotherapy (5-fluorouracil and cyclophosphamide) soon after diagnosis was established. The combined therapy was well tolerated by the patients, and complications were not severe and of a transient nature. The majority of patients showed a subjective and objective improvement: 75 per cent of patients had relief of bone pain, and 80 per cent reported relief in urinary symptoms. There was regression or stabilization of the primary tumor in 82.2 per cent. Disappearance or stabilization of osteoclastic lesions on bone scans was noted in 55.5 per cent of patients. The cumulative survival rate at eleven years is 55.5 per cent.