Intermittent hormonal therapy in the treatment of metastatic prostate cancer: a randomized trial

Androgen deprivation therapy impact on quality of life and cardiovascular health, monitoring therapeutic replacement

INTRODUCTION

Androgen deprivation therapy (ADT) is commonly utilized in the management of both localized and advanced adenocarcinoma of the prostate. The use of ADT is associated with several adverse events, physical changes, and development of medical comorbidities/mortality.

AIM

The current article reviews known adverse events associated with ADT as well as treatment options, where available. Current recommendations and guidelines are cited for ongoing monitoring of patients receiving ADT.

METHODS

A PubMed search of topics relating to ADT and adverse outcomes was performed, with select articles highlighted and reviewed based on level of evidence and overall contribution.

MAIN OUTCOME MEASURES

Reported outcomes of studies detailing adverse effects of ADT were reviewed and discussed. Where available, randomized trials and meta-analyses were reported.

RESULTS

ADT may result in several adverse events including decreased libido, erectile dysfunction, vasomotor symptoms, cognitive, psychological and quality of life impairments, weight gain, sarcopenia, increased adiposity, gynecomastia, reduced penile/testicular size, hair changes, periodontal disease, osteoporosis, increased fracture risk, diabetes and insulin resistance, hyperlipidemia, and anemia. The definitive impact of ADT on lipid profiles, cardiovascular morbidity/mortality, and all-cause mortality is currently unknown with available data. Treatment options to reduce ADT-related adverse events include changing to an intermittent treatment schedule, biophysical therapy, counseling, and pharmacotherapy.

CONCLUSIONS

Patients treated with ADT are at increased risk of several adverse events and should be routinely monitored for the development of potentially significant morbidity/mortality. Where appropriate, physicians should reduce known risk factors and counsel patients as to known risks and benefits of therapy.

Treatment of prostate cancer with intermittent versus continuous androgen deprivation: a systematic review of randomized trials

PURPOSE

Uncertainty exists regarding benefits of intermittent androgen deprivation (IAD) compared with continuous androgen deprivation (CAD) for treatment of prostate cancer. On the basis of a systematic review of evidence, our aim was to formulate a recommendation for either IAD or CAD to treat relapsing, locally advanced, or metastatic prostate cancer.

METHODS

We searched literature published up to September 2012 from MEDLINE, EMBASE, the Cochrane Library, and major conference proceedings. We included randomized controlled trials comparing IAD and CAD if they reported overall survival (OS) or biochemical/radiologic time to disease progression.

RESULTS

Nine studies with 5,508 patients met our criteria. There were no significant differences in time-to-event outcomes between the groups in any studies. The pooled hazard ratio (HR) for OS was 1.02 (95% CI, 0.94 to 1.11) for IAD compared with CAD, and the HR for progression-free survival was 0.96 (95% CI, 0.76 to 1.20). More prostate cancer-related deaths with IAD tended to be balanced by more deaths not related to prostate cancer with CAD. Superiority of IAD for sexual function, physical activity, and general well-being was observed in some trials. Median cost savings with IAD was estimated to be 48%.

CONCLUSION

There is fair evidence to recommend use of IAD instead of CAD for the treatment of men with relapsing, locally advanced, or metastatic prostate cancer who achieve a good initial response to androgen deprivation. This recommendation is based on evidence against superiority of either strategy for time-to-event outcomes and substantial decrease with IAD in exposure to androgen deprivation, resulting in less cost, inconvenience, and potential toxicity.

Intermittent androgen-deprivation therapy in prostate cancer: a critical review focused on phase 3 trials

CONTEXT

Intermittent androgen deprivation (IAD) in prostate cancer (PCa) patients has been proposed to delay development of castration resistance and to reduce the side effects and costs of androgen deprivation therapy (ADT).

OBJECTIVE

This review analyzes (1) the oncologic and quality of life (QoL) results from randomized phase 3 trials comparing IAD and continuous ADT and (2) the prognostic parameters for IAD.

EVIDENCE ACQUISITION

We searched the Medline and Cochrane Library databases (primary fields: prostate neoplasm and intermittent androgen deprivation; secondary fields: randomized trials, survival, quality of life, predictors) without language restriction.

EVIDENCE SYNTHESIS

We found seven extensively described phase 3 trials randomizing 4675 patients to IAD versus continuous ADT. Other randomized trials investigating IAD have been performed, but available data are limited and have been published only in preliminary fashion. In all seven trials, patients spent most of their time on, rather than off, ADT. The induction periods ranged from 3 mo to 8 mo; in all but one trial, the PSA level designated for ADT discontinuation was <4 ng/ml. Mean follow-up ranged from 40-108 mo. Collectively, these trials support the concept that, mainly in metastatic cases, IAD can produce oncologic results similar to continuous ADT. In terms of overall survival, the hazard ratios for IAD and continuous ADT were very similar (range: 0.98-1.08). The QoL benefit of IAD appears to be modest at best. With IAD, QoL is likely influenced by the duration of the off-treatment periods and by the rate of testosterone recovery.

CONCLUSIONS

The evidence indicates that IAD is not inferior to continuous ADT. Data are insufficient to determine whether IAD is able to prevent the long-term complications of ADT. More comparative analysis focused on QoL is warranted.

Combining T-cell immunotherapy and anti-androgen therapy for prostate cancer

BACKGROUND

Prostate cancer remains a significant health problem for men in the Western world. Although treatment modalities are available, these do not confer long-term benefit and are accompanied by substantial side effects. Adoptive immunotherapy represents an attractive alternative to conventional treatments as a means to control tumor growth.

METHODS

To selectively target the tumor-expressed form of Muc1 we constructed a retroviral vector encoding a chimeric antigen receptor (CAR) directed against the aberrantly-expressed extracellular portion of Muc1 called the 'variable number of tandem repeats'.

RESULTS

We now demonstrate that T cells can be genetically engineered to express a CAR targeting the tumor-associated antigen Muc1. CAR-Muc1 T cells were able to selectively kill Muc1-expressing human prostate cancer cells. However, we noted that heterogeneous expression of the Muc1 antigen on tumor cells facilitated immune escape and the outgrowth of target-antigen loss variants of the tumor. Given the importance of androgen ablation therapy in the management of metastatic prostate cancer, we therefore also tested the value of combining conventional (anti-androgen) and experimental (CAR-Muc1 T cells) approaches. We show that CAR-Muc1 T cells were not adversely impacted by anti-androgen therapy and subsequently demonstrate the feasibility of combining the approaches to produce additive anti-tumor effects in vitro.

CONCLUSIONS

Adoptive transfer of CAR-Muc1 T cells alone or in combination with other luteinizing hormone-releasing hormone analogs or antagonists should be tested in human clinical trials.

Advanced prostate cancer treated with intermittent or continuous androgen deprivation in the randomised FinnProstate Study VII: quality of life and adverse effects

BACKGROUND

Intermittent dosing may reduce the adverse events (AEs) of androgen-deprivation therapy (ADT).

OBJECTIVE

To compare intermittent androgen deprivation (IAD) and continuous androgen deprivation (CAD) with regard to health-related quality of life (QoL).

DESIGN, SETTING, AND PARTICIPANTS

A total of 852 men with advanced prostate cancer (PCa) were enrolled to receive goserelin acetate 3.6 mg every 28 d for 24 wk. A total of 554 patients whose prostate-specific antigen (PSA) decreased to <10 ng/ml or by ≥50% (<20 ng/ml at baseline) were randomised to IAD or CAD.

INTERVENTION

In the IAD arm, ADT was resumed for at least 24 wk whenever PSA increased >20 ng/ml or above baseline.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

QoL was monitored with a validated Cleary 30-item questionnaire and analysed by the Mann-Whitney U test, 0.5 standard deviation rule, and repeated measures analysis of variance. AEs and adverse drug reactions (ADRs) were analysed by the chi-square test.

RESULTS AND LIMITATIONS

Median follow-up was 65 mo. Significant differences in QoL emerged in activity limitation, physical capacity, and sexual functioning, favouring IAD. No significant differences emerged in the prevalence of AEs: 87 patients in the IAD arm (31.8%) and 95 in the CAD arm (33.9%) had cardiovascular (CV) AEs (p=0.59), with 25 (9.1%) and 29 (10.4%) withdrawn (p=0.62), and 21 (7.7%) and 24 (8.6%) dying because of a CV event (p=0.70), respectively; bone fractures occurred in 19 (6.9%) and 15 (5.4%) patients (p=0.44), respectively. Hot flushes or night sweats were the most common ADRs (47.1% vs 50.4%; p=0.44). Erectile dysfunction (15.7% vs 7.9%; p=0.042) and depressed mood (2.2 vs 0%; p=0.032) were more common in the IAD arm.

CONCLUSIONS

IAD showed benefits in the treatment of advanced PCa with respect to QoL. The prevalence of AEs was not significantly lower with IAD.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00293670.