American Society of Clinical Oncology recommendations for the initial hormonal management of androgen-sensitive metastatic, recurrent, or progressive prostate cancer

[Guidelines for Evaluating Treatment Response Based on Bone Scan for Metastatic Castration-Resistant Prostate Cancer: Prostate Cancer Clinical Trial Working Group 3 Recommendations]

In prostate cancer, the bone is the most common site of metastasis, and it is essential to evaluate metastatic bone lesions to assess the tumor burden and treatment response. Castration-resistant prostate cancer refers to the state wherein the cancer continues to progress despite a significant reduction of the sex hormone level and is associated with frequent distant metastasis. The Prostate Cancer Working Group 3 (PCWG3) released guidelines that aimed to standardize the assessment of treatment effects in castration-resistant prostate cancer using bone scintigraphy. However, these guidelines can be challenging to comprehend and implement in practical settings. The purpose of this review was to provide an overview of a specific image acquisition method and treatment response assessment for bone scintigraphy-based evaluation of bone lesions in metastatic castration-resistant prostate cancer, in accordance with the PCWG3 guidelines.

Androgen-targeting therapeutics mitigate the adverse effect of GnRH agonist on the risk of neurodegenerative disease in men treated for prostate cancer

BACKGROUND

Prostate cancer and multiple neurodegenerative diseases (NDD) share an age-associated pattern of onset. Therapy of prostate cancer is known to impact cognitive function. The objective of this study was to determine the impact of multiple classes of androgen-targeting therapeutics (ATT) on the risk of NDD.

METHODS

A retrospective cohort study of men aged 45 and older with prostate within the US-based Mariner claims data set between January 1 and 27, 2021. A propensity score approach was used to minimize measured and unmeasured selection bias. Disease risk was determined using Kaplan-Meier survival analyses.

RESULTS

Of the 1,798,648 men with prostate cancer, 209,722 met inclusion criteria. Mean (SD) follow-up was 6.4 (1.8) years. In the propensity score-matched population, exposure to ATT was associated with a minimal increase in NDD incidence (relative risk [RR], 1.07; 95% CI, 1.05-1.10; p < 0.001). However, GnRH agonists alone were associated with significantly increased NDD risk (RR, 1.47; 95% CI, 1.30-1.66; p <0.001). Abiraterone, commonly administered with GnRH agonists and low-dose prednisone, was associated with a significantly decreased risk (RR, 0.77; 95% CI, 0.68-0.87; p < 0.001) of any NDD.

CONCLUSIONS

Among patients with prostate cancer, GnRH agonist exposure was associated with an increased NDD risk. Abiraterone acetate reduced the risks of Alzheimer's disease and Parkinson's disease conferred by GnRH agonists, whereas the risk for ALS was reduced by androgen receptor inhibitors. Outcomes of these analyses contribute to addressing controversies in the field and indicate that GnRH agonism may be a predictable instigator of risk for NDD with opportunities for risk mitigation in combination with another ATT.

Association of pigment epithelium derived factor expression with cancer progression and prognosis: a meta-analysis study

BACKGROUND

Pigment epithelium derived factor (PEDF) is a secreted protein that strongly suppresses angiogenesis and directly inhibits cancer cells proliferation. The differential expression of PEDF has been observed in multiple types of human tumors. However, it is unclear as to how PEDF expression is associated with cancer progression and if PEDF could serve as a prognostic marker for cancer patients.

METHODS

We performed a comprehensive search for the studies on PEDF expression in 14 top-ranked types of solid tumor cancer with the highest incidence. A systemic approach was used to screen for qualified studies and to extract data. Meta-analysis was performed to investigate if PEDF expression is associated with the TNM staging, tumor size, lymph node invasion, distal metastasis and pathological grade of tumor in a pan-cancer manner. A Kaplan-Meier curve was plotted with the digitally-reconstituted patient survival data to study the effect of PEDF expression on the prognosis of cancer patients.

RESULTS

A total of nine studies were selected, reviewed and analyzed. Meta-analysis suggested that decreased PEDF protein expression was associated with higher TNM staging (OR = 2.13, 95% CI: 1.61-2.81), larger tumor size (OR = 1.42, 95% CI: 1.1-1.84), larger possibility of lymph node invasion (OR = 1.68, 95% CI: 1.26-2.22) and higher pathological grade (OR = 1.6, 95% CI: 1.2-2.13). No correlation was found between PEDF expression and tumor distal metastasis, gender or age. In addition, low PEDF protein level in tumor tissue is correlated with shorter overall survival (P < 0.05).

CONCLUSIONS

Low PEDF protein expression in cancer is significantly associated with more advanced cancer progression and significantly poorer survival. The differential clinical outcome among patients with various PEDF expression suggests its prognostic value.

Steroid Hormone Biosynthesis Metabolism Is Associated With Fatigue Related to Androgen Deprivation Therapy for Prostate Cancer

Background

Androgen deprivation therapy (ADT) is a cornerstone treatment for prostate cancer. Despite the clinical benefits, ADT is associated with multiple adverse effects including fatigue. The goal of the study was to examine metabolomic changes to better understand cancer-related fatigue specific to ADT treatment.

Methods

A total of 160 plasma samples collected from participants with (+ADT, n = 58) or without neoadjuvant ADT (−ADT, n = 102) prior to radiation therapy for treatment of non-metastatic localized prostate cancer were included in the study. Fatigue and sleep-related impairment were measured using the Patient Reported Outcomes Measurement Information System. Plasma metabolites were identified and measured using untargeted ultrahigh-performance liquid chromatography/mass spectrometry metabolomics analyses. Partial least square discriminant analysis was used to identify discriminant metabolite features, and the diagnostic performance of selected classifiers was quantified using AUROC curve analysis. Pathway enrichment analysis was performed using metabolite sets enrichment analyses.

Findings

Steroid hormone biosynthesis pathways, including androstenedione metabolism as well as androgen and estrogen metabolism, were overrepresented by metabolites that significantly discriminated samples in the +ADT from the −ADT group. Additional overrepresented metabolic pathways included amino acid metabolism, glutathione metabolism, and carnitine synthesis. Of the metabolites that were significantly different between the groups, steroid hormone biosynthesis metabolites were most significantly correlated with fatigue severity. Sleep-related impairment was strongly correlated with fatigue severity and inversely correlated with ADT-induced reduction in androsterone sulfate.

Conclusions

Patients with non-metastatic prostate cancer receiving neoadjuvant ADT prior to radiation therapy reported relatively more severe fatigue. Increased fatigue in this population may be attributable to sleep-related impairment associated with alterations in steroid hormone biosynthesis. Findings in this study provide a basis for further research of changes in sleep patterns and their role in this specific subcategory of cancer-related fatigue caused by the treatment.

Initial Management of Noncastrate Advanced, Recurrent, or Metastatic Prostate Cancer: ASCO Guideline Update

PURPOSE

Update all preceding ASCO guidelines on initial hormonal management of noncastrate advanced, recurrent, or metastatic prostate cancer.

METHODS

The Expert Panel based recommendations on a systematic literature review. Recommendations were approved by the Expert Panel and the ASCO Clinical Practice Guidelines Committee.

RESULTS

Four clinical practice guidelines, one clinical practice guidelines endorsement, 19 systematic reviews with or without meta-analyses, 47 phase III randomized controlled trials, nine cohort studies, and two review papers informed the guideline update.

RECOMMENDATIONS

Docetaxel, abiraterone, enzalutamide, or apalutamide, each when administered with androgen deprivation therapy (ADT), represent four separate standards of care for noncastrate metastatic prostate cancer. Currently, the use of any of these agents in any particular combination or series cannot be recommended. ADT plus docetaxel, abiraterone, enzalutamide, or apalutamide should be offered to men with metastatic noncastrate prostate cancer, including those who received prior therapies, but have not yet progressed. The combination of ADT plus abiraterone and prednisolone should be considered for men with noncastrate locally advanced nonmetastatic prostate cancer who have undergone radiotherapy, rather than castration monotherapy. Immediate ADT may be offered to men who initially present with noncastrate locally advanced nonmetastatic disease who have not undergone previous local treatment and are unwilling or unable to undergo radiotherapy. Intermittent ADT may be offered to men with high-risk biochemically recurrent nonmetastatic prostate cancer. Active surveillance may be offered to men with low-risk biochemically recurrent nonmetastatic prostate cancer. The panel does not support use of either micronized abiraterone acetate or the 250 mg dose of abiraterone with a low-fat breakfast in the noncastrate setting at this time.Additional information is available at www.asco.org/genitourinary-cancer-guidelines.

CMTM5-v1 inhibits cell proliferation and migration by downregulating oncogenic EGFR signaling in prostate cancer cells

Anomalous epidermal growth factor receptor (EGFR) signaling plays an important role in the progression of prostate cancer (PCa) and the transformation to castration-resistant PCa (CRPC). A novel tumor suppressor CKLF-like MARVEL transmembrane domain-containing member 5(CMTM5) has a MARVEL domain and may regulate transmembrane signaling. Thus, we postulated that CMTM5 could regulate EGFR and its downstream molecules to affect the biological behaviors of PCa cells. In this study, we found that CMTM5 was expressed in benign prostatic hyperplasia (BPH) tissues but was undetectable in PCa cells. However, the EGFR was upregulated in PCa cells, especially in two metastatic CRPC cell lines, PC3 and DU145. Furthermore, ectopic expression of CMTM5-v1 suppressed cell proliferation and migration and p-EGFR levels. Further investigation revealed that restoration of CMTM5-v1 inhibited not only EGF-mediated proliferation but also chemotactic migration by EGF in PC3 and DU145 cells. Moreover, mechanistic studies showed that CMTM5-v1 attenuated EGF-induced receptor signaling by repressing EGFR and Akt phosphorylation in PCa cells, which were essential for malignant features. Finally, CMTM5-v1can promote the sensitivity of PC3 cells to Gefetinib, a tyrosine kinase inhibitor (TKI) targeting the EGFR. These observations indicate that CMTM5-v1 suppressed PCa cells through EGFR signaling. The loss of CMTM5 may participate in the progression of PCa resulting from deregulated EGFR, and CMTM5 might be associated with the efficacy of TKIs in terms of their potent inhibition of EGFR and human epidermal growth factor-2 (HER2) activation.

Sensitivity of CE-MRI in detecting local recurrence after radical prostatectomy

AIM

The aim of our study was to evaluate the sensitivity of contrast-enhanced magnetic resonance (CE-MR) with phased array coil in the diagnosis of local recurrence in patients with prostate cancer after radical prostatectomy and referred for salvage radiotherapy (SRT).

MATERIALS AND METHODS

This retrospective study included 73 patients treated with SRT after radical prostatectomy in the period between September 2006 and November 2017. All patients performed a CE-MRI with phased array coil before the start of SRT. A total of 213 patients treated at the ASST Grande Ospedale Metropolitano Niguarda in the period between September 2006 and November 2017 with SRT after radical prostatectomy were reviewed. Seventy-three patients with a CE-MRI with phased array coil of the pelvis before the start of SRT were included in the present study.

RESULTS

At imaging review, recurrence local recurrent disease was diagnosed in 48 of 73 patients. By considering as reference standard the decrease in prostate-specific antigen (PSA) value after radiotherapy, we defined: 41 true positive (patients with MRI evidence of local recurrence and PSA value decreasing after SRT), 7 false positive (patients with MRI evidence of local recurrence without biochemical response after SRT), 3 true negative (patients without MRI evidence of local recurrence and stable or increased PSA value after SRT) and 22 false negative (patients without MRI evidence of local recurrence and PSA value decreasing after SRT) cases. The sensitivity values were calculated in relation to the PSA value before the start of treatment, obtaining a value of 74% for PSA above 0.2 ng/mL.

CONCLUSION

The sensitivity of CE-MRI in local recurrence detection after radical prostatectomy increases with increasing PSA values. CE-MRI with phased array coil can detect local recurrences after radical prostatectomy with a good sensitivity in patients with pre-RT PSA value above 0.2 ng/mL.

Utilization and Outcomes of Surgical Castration in Comparison to Medical Castration in Metastatic Prostate Cancer

Androgen deprivation therapy is the gold standard for metastatic prostate cancer, which can be achieved either by surgical or medical castration. In this study of 33,585 patients in the National Cancer Database, there was significant decline in the trend of utilization of surgical castration from 8.6% in 2004 to 3.1% in 2014. However, there was no survival difference with surgical castration when compared with medical castration. Increasing the utilization of surgical castration could help reduce health care expenditures. Patients and physicians need to be aware of treatment options and their financial implications.

Androgen-deprivation therapy impairs left ventricle functions in prostate cancer patients

BACKGROUND

Androgen-deprivation therapy (ADT) is a treatment option for locally advanced and metastatic prostate cancer (PCA). The aim of the study was to evaluate the effect of ADT on left ventricular (LV) functions assessed by speckle-tracking echocardiography (STE) in prostate cancer (PCA) patients.

METHODS

Forty-nine consecutive PCA patients (mean age 71.5 ± 6.7 years) who would be treated with radiotherapy and ADT and 32 consecutive PCA patients (mean age 71.9 ± 7.0 years) who would be treated with radical or partial prostatectomy and 42 age-matched healthy men (mean age 70.5 ± 9.1 years) were included in our study. The left ventricular functions were assessed by both conventional echocardiography and STE at baseline and 6 months later.

RESULTS

There were not any significant difference in characteristics of the patients and controls. There were not any significant differences in conventional echocardiographic measures at baseline and at 6th month among the PCA patients and controls. Although there were not any significant differences in STE measures at baseline among the PCA patients and controls, the strain measures of the PCA patients receiving ADT decreased significantly at the 6th month and were significantly lower compared to strain measures of PCA patients undergoing prostatectomy and controls. There was not any statistically significant difference in baseline and 6th-month strain measures of the PCA patients undergoing prostatectomy.

CONCLUSIONS

ADT might be associated with decrease in LV longitudinal, circumferential, and radial strain measures in patients with PCA. STE might be useful for early identification of LV subclinical impairment in PCA patients treated with ADT.

A robust LC-MS/MS assay with online cleanup for measurement of serum testosterone

Accurate measurement of low levels of testosterone is critical for diagnosis and treatment of androgen disorders. The very low concentrations of testosterone in children, females, and males with androgen suppression therapies necessitate the use of mass spectrometry-based methods. We aimed to develop a liquid chromatography with tandem mass spectrometry method with simplified sample preparation and online solid-phase extraction cleanup to achieve enhanced precision, accuracy, robustness, and cost-effectiveness. The assay was linear from 10 to 20 000 pg/mL with an analytical recovery of 93-104%. The total coefficient of variation was 2.5, 1.9, and 1.7% at concentration levels of 348, 5432, and 10 848 pg/mL, respectively. No significant carryover was observed from samples with concentrations up to 20 000 pg/mL. No significant interference was observed from androstenedione, dehydroepiandrosterone, epi-testosterone, and estriol. Comparison with CDC Hormone Standardization program (HoSt) reference samples with defined values (n = 40) showed a Deming regression slope of 0.963, intercept of 28.06 pg/mL, standard error of estimate was 66.9, a correlation coefficient of 0.9996, and a mean bias of -0.6%. The method met the accuracy criteria by the CDC HoSt program. In addition, we achieved >12 000 injections on a single analytical column without significant performance deterioration due to the specific online solid-phase extraction settings.

Comparing the Staging/Restaging Performance of 68Ga-Labeled Prostate-Specific Membrane Antigen and 18F-Choline PET/CT in Prostate Cancer: A Systematic Review and Meta-analysis

PURPOSE

PET/CT using prostate-specific membrane antigen (PSMA) and choline radiotracers is widely used for diagnosis of prostate cancer. However, the roles of and differences in diagnostic performance between these 2 radiotracers for prostate cancer are unclear. The aim of this study was to compare the staging and restaging performance of Ga-labeled PSMA and F-choline PET/CT imaging in prostate cancer.

METHODS

A comprehensive search was performed in PubMed for studies reporting the staging performance of Ga-PSMA and F-choline PET/CT in prostate cancer from the inception of the database to October 1, 2018, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Thirty-five studies were included in this systematic review and meta-analysis. Pooled estimates of patient- and lesion-based sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) for Ga-PSMA and F-choline PET/CT were calculated alongside 95% confidence intervals. Summary receiver operating characteristic curves were plotted, and the area under the summary receiver operating characteristic curve (AUC) was determined alongside the Q* index.

RESULTS

The patient-based overall pooled sensitivity, specificity, PLR, NLR, DOR, and AUC of Ga-PSMA PET/CT for staging in prostate cancer (13 studies) were 0.92, 0.94, 7.91, 0.14, 79.04, and 0.96, respectively, whereas those of F-choline PET/CT (16 studies) were 0.93, 0.83, 4.98, 0.10, 68.27, and 0.95. The lesion-based overall pooled sensitivity, specificity, PLR, NLR, DOR, and AUC of Ga-PSMA PET/CT for staging in prostate cancer (9 studies) were 0.83, 0.95, 23.30, 0.17, 153.58, and 0.94, respectively, and those of F-choline PET/CT (4 studies) were 0.81, 0.92, 8.59, 0.20, 44.82, and 0.98. In both patient- and lesion-based imaging, there was no statistically significant difference in the abilities of detecting or excluding prostate cancer between Ga-PSMA PET/CT and F-choline PET/CT.

CONCLUSIONS

For staging and restaging performance in patients with prostate cancer, there was no significant difference between Ga-PSMA PET/CT and F-choline PET/CT. Ga-PSMA PET/CT and F-choline PET/CT have demonstrated high diagnostic performance for accurate staging and restaging in patients with prostate cancer, and thus both should be considered for staging in this disease.

External validation and newly development of a nomogram to predict overall survival of abiraterone-treated, castration-resistant patients with metastatic prostate cancer

Abiraterone acetate is approved for the treatment of castration-resistant prostate cancer (CRPC); however, its effects vary. An accurate prediction model to identify patient groups that will benefit from abiraterone treatment is therefore urgently required. The Chi model exhibits a good profile for risk classification, although its utility for the chemotherapy-naive group is unclear. This study aimed to externally validate the Chi model and develop a new nomogram to predict overall survival (OS). We retrospectively analyzed a cohort of 110 patients. Patients were distributed among good-, intermediate-, and poor-risk groups, according to the Chi model. The good-, intermediate-, and poor-risk groups had a sample size of 59 (53.6%), 34 (30.9%), and 17 (15.5%) in our dataset, and a median OS of 48.4, 29.1, and 10.5 months, respectively. The C-index of external validation of Chi model was 0.726. Univariate and multivariate analyses identified low hemoglobin concentrations (<110 g l⁻¹), liver metastasis, and a short time interval from androgen deprivation therapy to abiraterone initiation (<36 months) as predictors of OS. Accordingly, a new nomogram was developed with a C-index equal to 0.757 (95% CI, 0.678–0.836). In conclusion, the Chi model predicted the prognosis of abiraterone-treated, chemotherapy-naive patients with mCRPC, and we developed a new nomogram to predict the overall survival of this group of patients with less parameters.

Effect of tocotrienol from Bixa orellana (annatto) on bone microstructure, calcium content, and biomechanical strength in a model of male osteoporosis induced by buserelin

BACKGROUND

Patients receiving androgen deprivation therapy experience secondary hypogonadism, associated bone loss, and increased fracture risk. It has been shown that tocotrienol from Bixa orellana (annatto) prevents skeletal microstructural changes in rats experiencing primary hypogonadism. However, its potential in preventing bone loss due to androgen deprivation therapy has not been tested. This study aimed to evaluate the skeletal protective effects of annatto tocotrienol using a buserelin-induced osteoporotic rat model.

METHODS

Forty-six male Sprague Dawley rats aged 3 months were randomized into six groups. The baseline control (n=6) was sacrificed at the onset of the study. The normal control (n=8) received corn oil (the vehicle of tocotrienol) orally daily and normal saline (the vehicle of buserelin) subcutaneously daily. The buserelin control (n=8) received corn oil orally daily and subcutaneous buserelin injection (75 µg/kg) daily. The calcium control (n=8) was supplemented with 1% calcium in drinking water and daily subcutaneous buserelin injection (75 µg/kg). The remaining rats were given daily oral annatto tocotrienol at 60 mg/kg (n=8) or 100 mg/kg (n=8) plus daily subcutaneous buserelin injection (75 µg/kg) (n=8). At the end of the experiment, the rats were euthanized and their blood, tibia, and femur were harvested. Structural changes of the tibial trabecular and cortical bone were examined using X-ray micro-computed tomography. Femoral bone calcium content and biomechanical strength were also evaluated.

RESULTS

Annatto tocotrienol at 60 and 100 mg/kg significantly prevented the deterioration of trabecular bone and cortical thickness in buserelin-treated rats (P<0.05). Both doses of annatto tocotrienol also improved femoral biomechanical strength and bone calcium content in buserelin-treated rats (P<0.05). The effects of annatto tocotrienol were comparable to calcium supplementation.

CONCLUSION

Annatto tocotrienol supplementation is effective in preventing degeneration of the bone induced by buserelin. Therefore, it is a potential antiosteoporotic agent for men receiving androgen deprivation therapy.

Androgen-independent LNCaP cells are a subline of LNCaP cells with a more aggressive phenotype and androgen suppresses their growth by inducing cell cycle arrest at the G1 phase

Androgen deprivation therapy (ADT, surgical or chemical castration) is the mainstay treatment for metastatic prostate cancer (PCa); however, patients ineluctably relapse despite extremely low androgen levels. This evolution of PCa indicates its lethal progression. In this study, to mimic the traits of clinical PCa progression in vitro, we investigated the alterations in the cell biological characteristics in androgen-independent LNCaP cells (LNCaP-AI cells) compared with LNCaP cells. We also examined the effects of androgen on LNCaP and LNCaP-AI cell proliferation, androgen receptor (AR) expression and prostate-specific antigen (PSA) secretion. Furthermore, AR was silenced in the LNCaP and LNCaP-AI cells to detect the roles taht AR plays in cell growth, apoptosis and PSA secretion. We found that prolonged androgen ablation increased the LNCaP-AI cell growth rate and cell invasiveness, and induced epithelial-mesenchymal transition in the LNCaP-AI cells. Moreover, despite the fact that the LNCaP and LNCaP-AI cells expressed equal amounts of AR protein, androgen induced a greater secretion of PSA in the LNCaP-AI cells than in the LNCaP cells. The proliferation of the LNCaP-AI cells was not dependent on, but was suppressed by androgen, which led to arrest at the G1 phase. Conversely, androgen significantly increased LNCaP cell proliferation by promoting the G1-S transition. Moreover, the silencing of AR suppressed LNCaP and LNCaP-AI cell growth by inducing cell cycle arrest at the G1 phase rather than promoting apoptosis, and reduced PSA secretion. On the whole, our data suggest that LNCaP-AI cells have a more more aggressive phenotype compared with the LNCaP cells; AR remains a critical factor in the LNCaP-AI cells, and androgen suppresses LNCaP-AI cell growth by blocking the cell cycle at the G1 phase.

Discrimination of local recurrence after radical prostatectomy: value of diffusion-weighted magnetic resonance imaging

Background

Multiparametric magnetic resonance is the most accurate imaging technique for prostate cancer detection, staging, localization, and aggressiveness evaluation. We assessed accuracy of diffusion-weighted imaging in local recurrence diagnosis after radical prostatectomy.

Materials and methods

A retrospective study was conducted in 118 patients with findings suggestive of local recurrence in dynamic contrast-enhanced-magnetic resonance imaging. Local recurrence was defined clinically as a rising prostate-specific antigen level (biochemical recurrence) without radiographic evidence of distant metastasis over 6 months after surgery. Eighty-four patients (71.2%) had local recurrence (group 1) and 34 (28.8%) showed no recurrence (group 2). The diagnostic accuracy of diffusion-weighted imaging was assessed, and factors associated with local recurrence were evaluated using multivariate logistic regression analysis. Additional accuracy analysis was carried out according to the size of the nodule.

Results

In post-operative findings, group 1 patients had significantly higher serum prostate-specific antigen (P = 0.001), larger enhancing nodules (P = 0.005), and more positive findings in diffusion-weighted imaging (P = 0.001) than group 2 patients. The sensitivity of diffusion-weighted imaging was significantly higher for nodules ≥1 cm than for all nodules (96.6 vs. 80.9%, P = 0.001), whereas the specificities were equivalent (100.0 vs. 97.1, P = 0.529). In multivariate analysis, a positive finding in diffusion-weighted imaging was the independent predictor of local recurrence (P = 0.005), along with pathologic T stage (P = 0.018).

Conclusions

Diffusion-weighted imaging is accurate in distinguishing recurrence from enhancing nodule on dynamic contrast-enhanced-magnetic resonance. Nodules showing decreased diffusion suggest local recurrence, especially if sized ≥1 cm.

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

INTRODUCTION

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

The Tumor Macroenvironment: Cancer-Promoting Networks Beyond Tumor Beds

During tumor progression, alterations within the systemic tumor environment, or macroenvironment, result in the promotion of tumor growth, tumor invasion to distal organs, and eventual metastatic disease. Distally produced hormones, commensal microbiota residing within mucosal surfaces, myeloid cells and even the bone marrow impact the systemic immune system, tumor growth, and metastatic spread. Understanding the reciprocal interactions between the cells and soluble factors within the macroenvironment and the primary tumor will enable the design of specific therapies that have the potential to prevent dissemination and metastatic spread. This chapter will summarize recent findings detailing how the primary tumor and systemic tumor macroenvironment coordinate malignant progression.

A multicenter retrospective analysis of sequential treatment of abiraterone acetate followed by docetaxel in Japanese patients with metastatic castration-resistant prostate cancer

OBJECTIVE

Abiraterone acetate and docetaxel are promising treatment options for metastatic castration-resistant prostate cancer patients. However, the optimal sequencing of these agents is unclear, and no previous reports discuss Japanese metastatic castration-resistant prostate cancer patients. The purpose of this analysis is to reveal the outcomes of Japanese metastatic castration-resistant prostate cancer patients treated with abiraterone acetate followed by docetaxel.

METHODS

We retrospectively reviewed Japanese Phase 1 and Phase 2 trials of metastatic castration-resistant prostate cancer patients treated with abiraterone acetate until disease progression and subsequently treated with docetaxel. The primary outcome measure was the rates of prostate-specific antigen declines ≧30 and ≧50%, respectively, with docetaxel. Secondary outcome measures included progression-free survival with docetaxel, and overall survival after initiation of abiraterone acetate and docetaxel. We performed correlation analysis between previous prostate-specific antigen response to abiraterone acetate and subsequent prostate-specific antigen response to docetaxel.

RESULTS

We identified 15 patients had experienced disease progression with abiraterone acetate and subsequently were treated with docetaxel. Prostate-specific antigen declines ≧30 and ≧50% with docetaxel were observed in five patients (33%) and two patients (13%), respectively. The median progression-free survival with docetaxel was 3.7 months (95% confidence interval: 2.9-4.6). The median overall survival from initiation of docetaxel and abiraterone acetate were 14.4 months (95% confidence interval: 6.3-22.4), and 25.7 months (95% confidence interval: 20.1-30.7), respectively. No significant correlation was observed between these prostate-specific antigen responses (Pearson r = 0.206, P = 0.46).

CONCLUSION

The efficacy of docetaxel in Japanese mCRPC patients that was resistant to abiraterone acetate was modest. The prostate-specific antigen response to previous abiraterone acetate could not predict the efficacy of subsequent docetaxel. Larger prospective trials are needed to validate these findings.

Evaluation of suspected soft tissue lesion in the prostate bed after radical prostatectomy using 3T multiparametric magnetic resonance imaging

PURPOSE

To investigate the usefulness of multiparametric MR imaging (mp-MRI) at 3T for evaluating suspected soft tissue lesion in the prostate bed after radical prostatectomy (RP).

MATERIALS AND METHODS

Forty-three patients with biochemical recurrence (BCR) who received RP underwent mp-MRI at 3T with a phased-array coil, including T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI) and dynamic contrast-enhanced imaging (DCE-MRI) and were enrolled in this study. All patients with BCR had a suspected soft tissue lesion in the prostate bed, followed by transrectal ultrasound-guided biopsy. As a control group, 14 consecutive patients without BCR who received RP were also enrolled. Two experienced radiologists independently analyzed four different imaging datasets.

RESULTS

For predicting local recurrence, the specificity, accuracy and area under the curve for both readers were significantly greater on all combined imaging datasets than on T2WI alone (P<0.05). The sensitivity of all combined imaging datasets in both readers was not statistically different with T2WI alone (P>0.05), except for combined T2WI and DWI. Inter-reader agreements for the four different imaging datasets were moderate.

CONCLUSION

DCE-MRI or DWI in combination with T2WI at 3T with a phased-array coil appears to be more useful than T2WI alone in evaluating suspected soft tissue lesion of the prostate bed after RP.

CMTM5 is reduced in prostate cancer and inhibits cancer cell growth in vitro and in vivo

PURPOSE

A novel tumor suppressor CKLF-like MARVEL transmembrane domain-containing member 5 (CMTM5) is reduced or undetectable in many kinds of cancers and inhibits tumor cells' malignant features. To explore its role in prostate cancer (PCa), we detected its expression patterns in prostate tissues and PCa cells, and determined its anti-proliferation functions in PCa cells in vitro and in vivo.

METHODS

The expression of CMTM5 in prostate tissue microarray, specimens and cell lines was evaluated by immunohistochemistry and Western blot, respectively. After being transfected with CMTM5 adenovirus or vector, the proliferation and migration of DU145 cells were detected by MTT assay and transwell assay, respectively. Furthermore, the effects of CMTM5 on tumor growth were performed in nude mice xenograft in vivo.

RESULTS

We found CMTM5 was reduced in PCa tissues and cells compared with BPH tissues, and its expression in PCa tissues was related to the Gleason score. Moreover, after being transfected with adenovirus, ectopic expression of CMTM5-v1 in DU145 cells led to significant inhibition of cell proliferation and migration compared with the control, which may be attributed to decreased Akt activity. Finally, restoration of CMTM5 significantly suppressed tumor growth in vivo.

CONCLUSIONS

These results indicate that CMTM5 is down-regulated in PCa and exhibit tumor suppressor activities in androgen-independent PCa cells. Loss of CMTM5 protein may be contributed to the development of PCa and it is a potential therapeutic target for castration-resistant prostate cancer.

Non-steroidal antiandrogen monotherapy compared with luteinising hormone-releasing hormone agonists or surgical castration monotherapy for advanced prostate cancer

BACKGROUND

Non-steroidal antiandrogens and castration are the main therapy options for advanced stages of prostate cancer. However, debate regarding the value of these treatment options continues.

OBJECTIVES

To assess the effects of non-steroidal antiandrogen monotherapy compared with luteinising hormone-releasing hormone agonists or surgical castration monotherapy for treating advanced stages of prostate cancer.

SEARCH METHODS

We searched the Cochrane Prostatic Diseases and Urologic Cancers Group Specialized Register (PROSTATE), the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Web of Science with Conference Proceedings, three trial registries and abstracts from three major conferences to 23 December 2013, together with reference lists, and contacted selected experts in the field and manufacturers.

SELECTION CRITERIA

We included randomised controlled trials comparing non-steroidal antiandrogen monotherapy with medical or surgical castration monotherapy for men in advanced stages of prostate cancer.

DATA COLLECTION AND ANALYSIS

One review author screened all titles and abstracts; only citations that were clearly irrelevant were excluded at this stage. Then, two review authors independently examined full-text reports, identified relevant studies, assessed the eligibility of studies for inclusion, assessed trial quality and extracted data. We contacted the study authors to request additional information. We used Review Manager 5 for data synthesis and used the fixed-effect model for heterogeneity less than 50%; we used the random-effects model for substantial or considerable heterogeneity.

MAIN RESULTS

Eleven studies involving 3060 randomly assigned participants were included in this review. The quality of evidence is hampered by risk of bias. Use of non-steroidal antiandrogens decreased overall survival (hazard ratio (HR) 1.24, 95% confidence interval (CI) 1.05 to 1.48, six studies, 2712 participants) and increased clinical progression (one year: risk ratio (RR) 1.25, 95% CI 1.08 to 1.45, five studies, 2067 participants; 70 weeks: RR 1.26, 95% CI 1.08 to 1.45, six studies, 2373 participants; two years: RR 1.14, 95% CI 1.04 to 1.25, three studies, 1336 participants), as well as treatment failure (one year: RR 1.19, 95% CI 1.02 to 1.38, four studies, 1539 participants; 70 weeks: RR 1.27, 95% CI 1.05 to 1.52, five studies, 1845 participants; two years: RR 1.14, 95% CI 1.05 to 1.24, two studies, 808 participants), compared with medical or surgical castration. The quality of evidence for overall survival, clinical progression and treatment failure was rated as moderate according to GRADE. Predefined subgroup analyses showed that use of non-steroidal antiandrogens, compared with castration, was less favourable for overall survival, clinical progression (at one year, 70 weeks, two years) and treatment failure (at one year, 70 weeks, two years) in men with metastatic disease. Use of non-steroidal antiandrogens also increased the risk for treatment discontinuation due to adverse events (RR 1.82, 95% CI 1.13 to 2.94, eight studies, 1559 participants), including events such as breast pain (RR 22.97, 95% CI 14.79 to 35.67, eight studies, 2670 participants), gynaecomastia (RR 8.43, 95% CI 3.19 to 22.28, nine studies, 2774 participants) and asthenia (RR 1.77, 95% CI 1.36 to 2.31, five studies, 2073 participants). The risk of other adverse events, such as hot flashes (RR 0.23, 95% CI 0.19 to 0.27, nine studies, 2774 participants), haemorrhage (RR 0.07, 95% CI 0.01 to 0.54, two studies, 546 participants), nocturia (RR 0.38, 95% CI 0.20 to 0.69, one study, 480 participants), fatigue (RR 0.52, 95% CI 0.31 to 0.88, one study, 51 participants), loss of sexual interest (RR 0.50, 95% CI 0.30 to 0.83, one study, 51 participants) and urinary frequency (RR 0.22, 95% CI 0.11 to 0.47, one study, 480 participants) was decreased when non-steroidal antiandrogens were used. The quality of evidence for breast pain, gynaecomastia and hot flashes was rated as moderate according to GRADE. The effects of non-steroidal antiandrogens on cancer-specific survival and biochemical progression remained unclear.

AUTHORS' CONCLUSIONS

Currently available evidence suggests that use of non-steroidal antiandrogen monotherapy compared with medical or surgical castration monotherapy for advanced prostate cancer is less effective in terms of overall survival, clinical progression, treatment failure and treatment discontinuation due to adverse events. Evidence quality was rated as moderate according to GRADE. Further research is likely to have an important impact on results for patients with advanced but non-metastatic prostate cancer treated with non-steroidal antiandrogen monotherapy. However, we believe that research is likely not necessary on non-steroidal antiandrogen monotherapy for men with metastatic prostate cancer. Only high-quality, randomised controlled trials with long-term follow-up should be conducted. If further research is planned to investigate biochemical progression, studies with standardised follow-up schedules using measurements of prostate-specific antigen based on current guidelines should be conducted.

Multiparametric MRI for recurrent prostate cancer post radical prostatectomy and postradiation therapy

The clinical suspicion of local recurrence of prostate cancer (PCa) after radical prostatectomy (RP) and after radiation therapy (RT) is based on the onset of biochemical failure. The aim of this paper was to review the current role of multiparametric-MRI (mp-MRI) in the detection of locoregional recurrence. A systematic literature search using the Medline and Cochrane Library databases was performed from January 1995 up to November 2013. Bibliographies of retrieved and review articles were also examined. Only those articles reporting complete data with clinical relevance for the present review were selected. This review article is divided into two major parts: the first one considers the role of mp-MRI in the detection of PCa local recurrence after RP; the second part provides an insight about the impact of mp-MRI in the depiction of locoregional recurrence after RT (interstitial or external beam). Published data indicate an emerging role for mp-MRI in the detection and localization of locally recurrent PCa both after RP and RT which represents an information of paramount importance to perform focal salvage treatments.

Advanced imaging for the early diagnosis of local recurrence prostate cancer after radical prostatectomy

Currently the diagnosis of local recurrence of prostate cancer (PCa) after radical prostatectomy (RT) is based on the onset of biochemical failure which is defined by two consecutive values of prostate-specific antigen (PSA) higher than 0.2 ng/mL. The aim of this paper was to review the current roles of advanced imaging in the detection of locoregional recurrence. A nonsystematic literature search using the Medline and Cochrane Library databases was performed up to November 2013. Bibliographies of retrieved and review articles were also examined. Only those articles reporting complete data with clinical relevance for the present review were selected. This review article is divided into two major parts: the first one considers the role of PET/CT in the restaging of PCa after RP; the second part is intended to provide the impact of multiparametric-MRI (mp-MRI) in the depiction of locoregional recurrence. Published data indicate an emerging role for mp-MRI in the depiction of locoregional recurrence, while the performance of PET/CT still remains unclear. Moreover Mp-MRI, thanks to functional techniques, allows to distinguish between residual glandular healthy tissue, scar/fibrotic tissue, granulation tissue, and tumour recurrence and it may also be able to assess the aggressiveness of nodule recurrence.

Pharmacologic suppression of JAK1/2 by JAK1/2 inhibitor AZD1480 potently inhibits IL-6-induced experimental prostate cancer metastases formation

Metastatic prostate cancer is lethal and lacks effective strategies for prevention or treatment, requiring novel therapeutic approaches. Interleukin-6 (IL-6) is a cytokine that has been linked with prostate cancer pathogenesis by multiple studies. However, the direct functional roles of IL-6 in prostate cancer growth and progression have been unclear. In the present study, we show that IL-6 is produced in distant metastases of clinical prostate cancers. IL-6-activated signaling pathways in prostate cancer cells induced a robust 7-fold increase in metastases formation in nude mice. We further show that IL-6 promoted migratory prostate cancer cell phenotype, including increased prostate cancer cell migration, microtubule reorganization, and heterotypic adhesion of prostate cancer cells to endothelial cells. IL-6-driven metastasis was predominantly mediated by Stat3 and to lesser extent by ERK1/2. Most importantly, pharmacologic inhibition of Jak1/2 by AZD1480 suppressed IL-6-induced signaling, migratory prostate cancer cell phenotypes, and metastatic dissemination of prostate cancer in vivo in nude mice. In conclusion, we demonstrate that the cytokine IL-6 directly promotes prostate cancer metastasis in vitro and in vivo via Jak-Stat3 signaling pathway, and that IL-6-driven metastasis can be effectively suppressed by pharmacologic targeting of Jak1/2 using Jak1/2 inhibitor AZD1480. Our results therefore provide a strong rationale for further development of Jak1/2 inhibitors as therapy for metastatic prostate cancer.

Leuprolide acetate given by a subcutaneous extended-release injection: less of a pain?

Androgen deprivation therapy is a mainstay for the treatment of advanced prostate cancer. Hormonal therapy commonly consists of injection of gonadotropin hormone-releasing hormone agonists. Based on the need for improved convenience of administration, a novel formulation of leuprolide acetate (Eligard; Atrix Laboratories Inc. & Sanofi Aventis) which incorporates a mixture of selected polymers and solvents to achieve sustained drug delivery after subcutaneous injection, was developed. The US Food and Drug Administration has approved 1-, 3-, 4- and 6-month formulations of leuprolide acetate. In clinical trials, leuprolide acetate achieves sustained suppression of serum testosterone to castration levels (< or =50 ng/dl). The adverse-event profile is consistent with the effects of testosterone suppression. This novel delivery system in addition to the availability of a 6-month formulation of leuprolide acetate, offers patients the option of a convenient twice-yearly injection schedule.

Pituitary apoplexy induced by Gonadotropin-releasing hormone agonists for treating prostate cancer-report of first Asian case

We present the first Asian case of a 77-year-old man who developed pituitary apoplexy (PA) soon after gonadotropin-releasing hormone agonist (GnRHa) (leuprorelin) injection to treat prostate cancer. Headache, ophthalmoplegia, visual field deficit, nausea, and vomiting are the typical characteristics of pituitary apoplexy. Though the occurrence rate is rare, the consequence of this condition can vary from mild symptoms such as headache to life-threatening scenarios like conscious change. Magnetic resonance imaging is the best imaging modality to detect PA and sublabial trans-sphenoid pituitary tumor removal can resolve most of PA symptoms and is so far the best solution in consensus. We also review 11 previous reported cases receiving GnRHa for androgen deprivation therapy of prostate cancer, and hope to alert clinicians to use GnRHa with caution.

Hormonal therapy with external radiation therapy for metastatic spinal cord compression from newly diagnosed prostate cancer

BACKGROUND

Although hormonal therapy is effective for treatment of prostate cancer, its effect in the treatment of metastatic spinal cord compression (MSCC) has not been established. The objective of this study was to clarify the efficacy of conservative treatment of MSCC-induced paralysis resulting from prostate cancer for patients without a previous treatment history.

METHODS

We reviewed data from 38 patients with MSCC-induced paralysis from newly diagnosed prostate cancer who presented to our service between 1984 and 2010. Conservative treatment consisted of hormonal therapy with external radiation therapy (ERT). Patient demographic data, treatment details, involved spine MRI images, complications, and the course of neurologic recovery were investigated.

RESULTS

Twenty-five patients were treated conservatively. Mean follow-up period was 36.8 months. Sixteen patients (two with Frankel B, 14 with Frankel C) were unable to walk at initial presentation. After initiating conservative treatment, 75% (12 of 16) of these patients regained the ability to walk within 1 month, 88% (14 in 16) did so within 3 months, and all non-ambulatory patients did so within 6 months. No one had morbid complications. Four patients who did not regain the ability to walk at 1 month were found to have progressed to paraplegia rapidly, and tended to have severe compression as visualized on MRI, with a delay in the start of treatment in comparison with those who did so within 1 month (21.0 vs. 7.8 days).

CONCLUSIONS

Hormonal therapy associated with ERT is an important option for treatment of MSCC resulting from newly diagnosed prostate cancer.

Evaluation of primary androgen deprivation therapy in prostate cancer patients using the J-CAPRA risk score

Purpose:

To determine the influence of maximal androgen blockade (MAB) and non-MAB hormonal therapy with an luteinizing hormone releasing hormone (LHRH) analog on overall survival of prostate cancer patients in the Japan Study Group of Prostate Cancer (J-CaP) registry according to risk, as assessed using the novel J-CAPRA risk instrument. To undertake a multivariate analysis combining J-CAPRA risk score, type of hormonal therapy and comorbidities, in order to assess their impact on overall survival.

Methods:

The J-CaP database includes men in Japan diagnosed with any stage of prostate cancer between 2001 and 2003 and treated with primary androgen deprivation therapy (PADT), as monotherapy or in combination. A total of 26,272 men were enrolled and of these 19,265 were treated with PADT. This analysis was undertaken using the latest data set (30 April, 2010) including a total of 15,727 patients who received PADT and had follow-up data for periods ranging from 0 to 9.2 years.

Results:

MAB for prostate cancer patients with intermediate- or high-risk disease has a significant benefit in terms of overall survival compared with LHRH analog monotherapy or surgical castration alone. Better results may be achieved in older (≥75 years) patients. Patient comorbidities are an important factor in determining overall survival, notably in older patients, and should be considered when selecting therapy.

Conclusions:

Based on large-scale registry data, this report is the first to analyze the outcomes of MAB therapy in patients with prostate cancer at a wide range of disease stages. MAB therapy may provide significant survival benefits in intermediate- and high-risk patients.

An economic analysis of conservative management versus active treatment for men with localized prostate cancer

Comparative effectiveness research suggests that conservative management (CM) strategies are no less effective than active initial treatment for many men with localized prostate cancer. We estimate longer-term costs of initial management strategies and potential US health expenditure savings by increased use of conservative management for men with localized prostate cancer. Five-year total health expenditures attributed to initial management strategies for localized prostate cancer were calculated using commercial claims data from 1998 to 2006, and savings were estimated from a US population health-care expenditure model. Our analysis finds that patients receiving combinations of active treatments have the highest additional costs over conservative management at $63 500, followed by $48 550 for intensity-modulated radiation therapy, $37 500 for primary androgen deprivation therapy, and $28 600 for brachytherapy. Radical prostatectomy ($15 200) and external beam radiation therapy ($18 900) were associated with the lowest costs. The population model estimated that US health expenditures could be lowered by 1) use of initial CM over all active treatment ($2.9-3.25 billion annual savings), 2) shifting patients receiving intensity-modulated radiation therapy to CM ($680-930 million), 3) foregoing primary androgen deprivation therapy($555 million), 4) reducing the use of adjuvant androgen deprivation in addition to local therapies ($630 million), and 5) using single treatments rather than combination local treatment ($620-655 million). In conclusion, we find that all active treatments are associated with higher longer-term costs than CM. Substantial savings, representing up to 30% of total costs, could be realized by adopting CM strategies, including active surveillance, for initial management of men with localized prostate cancer.

STAT5A/B gene locus undergoes amplification during human prostate cancer progression

The molecular mechanisms underlying progression of prostate cancer (PCa) to castrate-resistant (CR) and metastatic disease are poorly understood. Our previous mechanistic work shows that inhibition of transcription factor Stat5 by multiple alternative methods induces extensive rapid apoptotic death of Stat5-positive PCa cells in vitro and inhibits PCa xenograft tumor growth in nude mice. Furthermore, STAT5A/B induces invasive behavior of PCa cells in vitro and in vivo, suggesting involvement of STAT5A/B in PCa progression. Nuclear STAT5A/B protein levels are increased in high-grade PCas, CR PCas, and distant metastases, and high nuclear STAT5A/B expression predicts early disease recurrence and PCa-specific death in clinical PCas. Based on these findings, STAT5A/B represents a therapeutic target protein for advanced PCa. The mechanisms underlying increased Stat5 protein levels in PCa are unclear. Herein, we demonstrate amplification at the STAT5A/B gene locus in a significant fraction of clinical PCa specimens. STAT5A/B gene amplification was more frequently found in PCas of high histologic grades and in CR distant metastases. Quantitative in situ analysis revealed that STAT5A/B gene amplification was associated with increased STAT5A/B protein expression in PCa. Functional studies showed that increased STAT5A/B copy numbers conferred growth advantage in PCa cells in vitro and as xenograft tumors in vivo. The work presented herein provides the first evidence of somatic STAT5A/B gene amplification in clinical PCas.

Isotope-Dilution Liquid Chromatography–Tandem Mass Spectrometry Candidate Reference Method for Total Testosterone in Human Serum

BACKGROUND

We developed and evaluated a candidate reference measurement procedure (RMP) to standardize testosterone measurements, provide highly accurate and precise value assignments for the CDC Hormone Standardization Program, and ensure accurate and comparable results across testing systems and laboratories.

METHODS

After 2 liquid/liquid extractions of serum with a combination of ethyl acetate and hexane, we quantified testosterone by isotope-dilution liquid chromatography–tandem mass spectrometry with electrospray ionization in the positive ion mode monitoring 289→97 m/z (testosterone) and 292→112 m/z (3C13 testosterone). We used calibrator bracketing and gravimetric measurements to give higher specificity and accuracy to serum value assignments. The candidate RMP was evaluated for accuracy by use of NIST-certified reference material SRM971 and validated by split-sample comparison to established RMPs. We evaluated intraassay and interassay imprecision, measurement uncertainty, potential interferences, and matrix effects.

RESULTS

A weighted Deming regression comparison of the candidate RMP to established RMPs showed agreement with no statistical difference (slope 0.99, 95% CI 0.98–1.00, intercept 0.54, 95% CI −1.24 to 2.32) and a bias of ≤0.3% for NIST SRM971. The candidate RMP gave maximum intraassay, interassay, and total percent CVs of 1.5%, 1.4%, and 1.7% across the concentrations of testosterone typically found in healthy men and women. We tested structural analogs of testosterone and 125 serum samples and found no interferences with the measurement.

CONCLUSIONS

This RMP for testosterone can serve as a higher-order standard for measurement traceability and can be used to provide an accuracy base to which routine methods can be compared in the CDC Hormone Standardization Program.

Transdermal estradiol in castrate and chemotherapy resistant prostate cancer

BACKGROUND

Given prior studies demonstrating the marked clinical activity of oral estrogens in prostate cancer, more recent data demonstrating the safety of transdermal estradiol, and the renewed interest in targeting testosterone metabolism and androgen receptor pathways, we report the results of a trial of transdermal estradiol in advanced heavily pre-treated castrate and chemotherapy refractory patients.

MATERIAL/METHODS

Patients with prostate cancer progressing after androgen ablation therapy and chemotherapy were treated with transdermal estradiol patches (0.4 mg per 24 hours total) applied weekly and assessed for tolerability and biochemical activity.

RESULTS

Twenty-two patients were treated on study with all patients evaluable for safety and 20 patients evaluable for response. All patients had aggressive and resistant disease, as demonstrated by a median PSA of 170 ng/mL (range 14 to 5030 ng/mL), with more than 60% having been treated with two or more prior chemotherapy regimens, and 20% with visceral disease. Nine patients had a decrease in PSA, of which two patients had a PSA response defined as a decline in PSA by 50%. Therapy was well tolerated and no thrombotic events were observed.

CONCLUSIONS

In heavily pre-treated patients with advanced castrate and chemotherapy refractory metastatic prostate cancer, transdermal estradiol was safe and had biochemical activity. These data support further studies to understand if transdermal estradiol can be useful following multiple standard therapies.

New and emerging agents for the treatment of castration-resistant prostate cancer

Most men with recurrent prostate cancer (CaP) initially respond to androgen deprivation therapy but eventually develop metastatic castration-resistant prostate cancer (CRPC). Over the last decade, new therapeutic targets have been identified in CRPC and several new drugs have reached advanced stages of clinical development. In 2010, the Food and Drug Administration (FDA) approved sipuleucel-T and cabazitaxel, and in 2011, abiraterone for patients with metastatic CRPC based on phase 3 trials showing improved survival. Although not yet available for clinical use, a press release in June 2011 announced that radium 223 also demonstrated a survival advantage in men with metastatic CRPC. Emerging therapies in advanced stages of clinical development in CRPC include the hormonal therapies MDV3100 and TAK 700, and the immunotherapy ipilimumab. Results are also pending on phase 3 studies comparing docetaxel plus prednisone with docetaxel given with the novel agents aflibercept, dasatinib, lenalidomide, and custirsen. In addition to these new and emerging therapeutic agents, denosumab was approved for the prevention of skeletal complications in patients with bone metastases due to solid tumor malignancies, providing an alternative to zoledronic acid. While the addition of these new treatment options is a great advance for men with metastatic CRPC, there are many new questions arising regarding sequencing of these treatments with each other, with previously existing therapies, and with the emerging agents now in clinical trials. Furthermore, there are concerns that on-going phase 3 trials may be contaminated if patients go off study treatment to start 1 of the newly approved agents or take the agent subsequently. These realities make clinical trial design more challenging than ever.

Use of androgen deprivation therapy in prostate cancer: indications and prevalence

Androgens play a prominent role in the development, maintenance and progression of prostate cancer. The introduction of androgen deprivation therapies into the treatment paradigm for prostate cancer patients has resulted in a wide variety of benefits ranging from a survival advantage for those with clinically localized or locally advanced disease, to improvements in symptom control for patients with advanced disease. Controversies remain, however, surrounding the optimal timing, duration and schedule of these hormonal approaches. Newer hormonal manipulations such as abiraterone acetate have also been investigated and will broaden treatment options for men with prostate cancer. This review highlights the various androgen-directed treatment options available to men with prostate cancer, their specific indications and the evidence supporting each approach, as well as patterns of use of hormonal therapies.

Hormonal therapy promotes hormone-resistant phenotype by increasing DNMT activity and expression in prostate cancer models

We hypothesized that hormonal therapy favors the development of the hormone-resistant phenotype through epigenetic mechanisms. Human prostate cancer tissues and in vitro and in vivo models were used to verify this hypothesis. We demonstrated that tumor cells continuously treated with bicalutamide (BCLT) or cultured in androgen-depleted medium progressively acquire higher DNA methyltransferase (DNMT) activity and expression than cells cultured in standard condition. Increased DNMT expression and activity also paralleled the up-regulation of truncated AR isoforms, which favors the development of the hormone-resistant phenotype. After androgen stimulation with 10(-12) m dihydrotestosterone, DNMT activity was significantly reduced in comparison with hormonal therapy. Consistent with these observations, the silencing of DNMT3a and DNMT3b significantly decreased the DNMT activity levels. These findings were also directly correlated with phosphatase and tensin homolog down-regulation and activation of ERK and phosphatidylinositol 3-kinases/AKT8 virus oncogene cellular homolog pathways. The use of a pan-DNMT inhibitor (5-Azacitidine) greatly reduced the development of the hormone-resistant phenotype induced by long-term BCLT treatment, and this finding correlated with low DNMT activity. The regulation of DNMT activity was, in some measure, dependent on the androgen receptor, as small interfering RNA treatment targeting the androgen receptor greatly decreased the modulation of DNMT activity under androgenic and antiandrogenic stimulation. These observations were correlated in vivo in patients, as demonstrated by immunohistochemistry. Patients treated by BCLT before surgery had higher DNMT3a and DNMT3b expression than patients who had not undergone this treatment. Our findings provide evidence of a relationship between the castration-resistant phenotype and DNMT expression and activity in human prostate cancer.

Hormone use after radiotherapy failure: a survey of Canadian uro-oncology specialists

INTRODUCTION

A survey of Canadian uro-oncology specialists was performed to assess practice patterns of patients with recurrent prostate cancer postradiotherapy and to assess the feasibility of conducting a trial in this setting.

METHODS

There were 14 survey questions and 1 demographic question. Responses were reported by frequency.

RESULTS

There were 96 respondents. Most respondents use both prostate-specific antigen doubling time (PSAdt) and PSA level when deciding to start androgen deprivation therapy (ADT) in asymptomatic patients. About half of respondents start ADT when PSA is greater than 10 ng/mL or when the PSAdt is less than 6 months. Eighty-six percent felt that the timing of ADT was an important research question. Over 1500 patients per year were estimated as being available for such a trial.

CONCLUSION

After radiotherapy failure, respondents initiated ADT about half of the time when PSA is less than 10 ng/mL and/or PSAdt is less than 6 months. A clinical trial examining the timing of ADT has strong support and appears to be feasible.

A comparison of androgen deprivation therapy versus surgical castration for patients with advanced prostatic carcinoma

AIM

To examine the outcomes of patients with advanced prostate carcinoma who underwent medical or surgical castration.

METHODS

A hundred twenty one consecutive cases of patients with advanced prostate carcinoma who underwent medical or surgical castration between 2001 and 2006 were retrospectively reviewed. Associations between clinical outcomes and prognostic scoring factors were determined based on the Reijke study. In the surgical and medical castration groups, the impact on the prostate-specific antigen (PSA) normalization rate, the rebound rate and the disease-free survival rate were evaluated. The mean follow-up was 36.1 months.

RESULTS

In the initial 12 months, there were no statistical differences in the PSA normalization rate and the PSA rebound rate between the two groups. However, the PSA rebound rate after the 12th month (20.90% vs 40.74%, P=0.0175) and the 18th month PSA normalization rate (59.70% vs 37.04%, P=0.0217) differed significantly between the two groups, and these differences were maintained to the end of the study. When comparing patients grouped according to Reijke prognosis scores, there was no difference between medical and surgical castration for the good prognosis group. However, among the patients given a poor prognosis, surgical castration was superior in terms of the PSA normalization rate, the PSA rebound rate, the tumor progression-free survival rate (P<0.001) and the overall survival rate (P<0.001).

CONCLUSION

Advanced prostate carcinoma patients with poor pretreatment prognosis scores should undergo surgical castration rather than medical castration for better PSA rebound rates and overall survival.