Cannabidiol alters mitochondrial bioenergetics via VDAC1 and triggers cell death in hormone-refractory prostate cancer.

In spite of the huge advancements in both diagnosis and interventions, hormone refractory prostate cancer (HRPC) remains a major hurdle in prostate cancer (PCa). Metabolic reprogramming plays a key role in PCa oncogenesis and resistance. However, the dynamics between metabolism and oncogenesis are not fully understood. Here, we demonstrate that two multi-target natural products, cannabidiol (CBD) and cannabigerol (CBG), suppress HRPC development in the TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) model by reprogramming metabolic and oncogenic signaling. Mechanistically, CBD increases glycolytic capacity and inhibits oxidative phosphorylation in enzalutamide-resistant HRPC cells. This action of CBD originates from its effect on metabolic plasticity via modulation of VDAC1 and hexokinase II (HKII) coupling on the outer mitochondrial membrane, which leads to strong shifts of mitochondrial functions and oncogenic signaling pathways. The effect of CBG on enzalutamide-resistant HRPC cells was less pronounced than CBD and only partially attributable to its action on mitochondria. However, when optimally combined, these two cannabinoids exhibited strong anti-tumor effects in TRAMP mice, even when these had become refractory to enzalutamide, thus pointing to their therapeutical potential against PCa.

Adding carboplatin to chemotherapy regimens for metastatic castrate-resistant prostate cancer in postsecond generation hormone therapy setting: Impact on treatment response and survival outcomes.

BACKGROUND: The clinical course in metastatic castrate-resistant prostate cancer (mCRPC) can be complicated when patients have disease progression after prior treatment with second generation hormone therapy (second HT), such as enzalutamide or abiraterone. Currently, limited data exist regarding the optimal choice of chemotherapy for mCRPC after failing second generation hormone therapy. We sought to evaluate three common chemotherapy regimens in this setting. METHODS: We retrospectively identified 150 mCRPC patients with disease progression on enzalutamide or abiraterone. Of these 150 patients, 92 patients were chemo-naïve while 58 patients had previously received docetaxel chemotherapy before being started on second HT. After failing second HT, 90 patients were assigned for docetaxel-alone (group A), 33 patients received carboplatin plus docetaxel (group B), while 27 patients received cabazitaxel-alone (Group C). A favorable response was defined by more than or equal to 50% reduction in prostate-specific antigen from the baseline level after a complete course of chemotherapy. Survival outcomes were assessed for 30-month overall survival. RESULTS: Patients in group (B) were 2.6 times as likely to have a favorable response compared to patients in group (A) (OR = 2.625, 95%CI: 1.15-5.99) and almost three times compared to patients in group (C) (OR = 2.975, 95%CI: 1.04-8.54) (P = .0442). 30-month overall survival was 70.7%, 38.9% and 30.3% for group (B), (A), and (C), respectively (P = .008). We report a Hazard Ratio of 3.1 (95% CI, 1.31-7.35; P = .0037) between patients in group (A) versus those in group (B) and a Hazard Ratio of 4.18 (95% CI, 1.58-11.06; P = .0037) between patients in group (C) compared to those in group (B) CONCLUSION: This data demonstrates improved response and overall survival in treatment-refractory mCRPC with a chemotherapy regimen of docetaxel plus carboplatin when compared to docetaxel alone or cabazitaxel alone. Further investigations are required.

Leptomeningeal Metastases in Hormone Refractory Prostate Cancer.

Leptomeningeal metastases from the prostate are extremely rare, with few cases described in the medical literature (antemortem prevalence of less than 0.03%). Prostatic leptomeningeal metastases harbour a poor prognosis with a median survival after diagnosis of 15.7 weeks. We present the case of an 82-year-old male with a history of hormone-refractory prostate cancer who presented to the emergency department with neurological symptoms.

A Systematic Review of Clinical Practice Guidelines for Castration-Resistant Prostate Cancer.

Cancer constitutes a huge burden on societies in countries with any level of economic development. Prostate cancer is the first most diagnosed cancer of men in developed countries and the forth one in developing countries in terms of incidence rate. It is also the third incident cancer of men in Iran along with a prevalence of about 10,000 cases. Castration-resistant prostate cancer (CRPC) is a severe stage of the disease with a number of newly discovered treatment options. These therapeutic alternatives including abiraterone acetate, enzalutamide, cabazitaxel, immunotherapy with sipuleucel-T, radiopharmaceuticals and bone-targeted therapies (zoledronic acid, denosumab) along with docetaxel have made the decision making process complex and challenging for clinicians. In addition to the challenges of selecting the best-fit treatment, high costs of new pharmaceuticals and technologies necessitates the health policy-makers to develop practice guidelines in adaptation with local resources and limitations. The aim of this paper is to review the clinical guidelines for the management of CRPC. For better comprehension of guideline recommendations, the main clinical trials on new treatments were also identified. The efficacy and safety outcomes including but not limited to overall survival, progression free survival, quality of life and adverse effects were summarized. The guidelines of American Urological Association (AUA), National Comprehensive Cancer Network (NCCN), European Association of Urology (EUA), Spanish Oncology Genitourinary Group (SOGG), Asian Oncology Summit, Saudi Oncology Society-Saudi Urology Association combined guideline, National Institute for Health and Care Excellence (NICE) and Canadian Urological Association-Canadian Urologic Oncology Group (CUA-CUOG) were covered in this paper.

223Ra-chloride therapy in men with hormone-refractory prostate cancer and skeletal metastases: Real-world experience.

BACKGROUND: Radium-223 (223Ra) chloride, an alpha emitter, has been shown to improve overall survival (OS) and pain control, and to delay skeletal-related events, in patients with castration-resistant prostate cancer (CRPC) and bone metastases. Our retrospective observational study presents the first Italian experience on the efficacy and safety of 223Ra therapy in routine clinical practice. METHODS: A total of 83 patients with metastatic CRPC were treated with 223Ra at 3 Italian centers between August 2013 and August 2016. 223Ra-chloride (55 kBq/kg) was administered every 4 weeks for a total of 6 cycles. Primary endpoints were OS and progression-free survival (PFS). Secondary endpoints included toxicity, pain evaluation using numeric rating scale (NRS), symptomatic skeletal-related events and biomarkers response. RESULTS: Patients had a median age of 75 (range 53-89) years. The majority of men showed a Gleason score of 7, 8, or 9. Forty-one patients completed 6 treatment cycles; 33 stopped treatment before completing 6 cycles. Nine were still receiving therapy at the time of data collection. At the end of therapy, NRS pain scores significantly improved ( p < .000001). OS was a mean of 10.1 months, while median OS had not been attained. According to Kaplan-Meier estimation, OS and PFS were 17.5 and 7.7 months, respectively. There was a significant correlation between OS and PFS with the number of 223Ra cycles; patients receiving all 6 cycles experienced the major benefit from the therapy. 223Ra was well-tolerated. CONCLUSIONS: 223Ra alpha therapy is an important therapeutic option for men with CRPC and symptomatic skeletal metastases.

Maspin Enhances the Anticancer Activity of Curcumin in Hormone-refractory Prostate Cancer Cells.

BACKGROUND/AIM: Androgen deprivation therapy remains the principal treatment for patients with advanced prostate cancer, though, most patients will eventually develop hormone-refractory prostate cancer (HRPC). Androgen ablation mediated maspin-induction has been identified in cancer patients. However, the role of maspin on the anticancer activity of curcumin derived from turmeric (Curcuma longa) in HRPC cells has not been elucidated. MATERIALS AND METHODS: The anticancer action of curcumin in hormone-independent prostate cancer cells (DU145, and PC-3) was determined by measures of cell survival rate. The cause of maspin silencing on the anti-tumor abilities of curcumin in PC-3 cells was evaluated by measures of cell survival rate, cell-cycle distribution, and apoptosis signaling analysis. RESULTS: Our present study showed that PC-3 cells (with higher maspin expression) were more sensitive than DU145 cells to curcumin treatment (with lower maspin expression). RNA interference-mediated maspin silencing reduced curcumin sensitivity of PC-3 cells, as evidenced by reduced apoptotic cell death. After exposure to curcumin, maspin-knockdown cells showed lower expression levels of pro-apoptotic proteins, Bad and Bax, as compared with control cells. CONCLUSION: Maspin can enhance the sensitivity of HRPC cells to curcumin treatment.

Enantiomerically pure ß-dipeptide derivative induces anticancer activity against human hormone-refractory prostate cancer through both PI3K/Akt-dependent and -independent pathways.

The use of peptides that target cancer cells and induce anticancer activities through various mechanisms is developing as a potential anticancer strategy. KUD983, an enantiomerically pure ß-dipeptide derivative, displays potent activity against hormone-refractory prostate cancer (HRPC) PC-3 and DU145 cells with submicromolar IC50. KUD983 induced G1 arrest of the cell cycle and subsequent apoptosis associated with down-regulation of several related proteins including cyclin D1, cyclin E and Cdk4, and the de-phosphorylation of RB. The levels of nuclear and total c-Myc protein, which could increase the expression of both cyclin D1 and cyclin E, were profoundly inhibited by KUD983. Furthermore, it inhibited PI3K/Akt and mTOR/p70S6K/4E-BP1 pathways, the key signaling in multiple cellular functions. The transient transfection of constitutively active myristylated Akt (myr-Akt) cDNA significantly rescued KUD983-induced caspase activation but did not blunt the inhibition of mTOR/p70S6K/4E-BP1 signaling cascade suggesting the presence of both Akt-dependent and -independent pathways. Moreover, KUD983-induced effect was enhanced with the down-regulation of anti-apoptotic Bcl-2 members (e.g., Bcl-2, and Mcl-1) and IAP family members (e.g., survivin). Notably, KUD983 induced autophagic cell death using confocal microscopic examination, tracking the level of conversion of LC3-I to LC3-II and flow cytometric detection of acidic vesicular organelles-positive cells. In conclusion, the data suggest that KUD983 is an anticancer ß-dipeptide against HRPCs through the inhibition of cell proliferation and induction of apoptotic and autophagic cell death. The suppression of signaling pathways regulated by c-Myc, PI3K/Akt and mTOR/p70S6K/4E-BP1 and the collaboration with down-regulation of Mcl-1 and survivin may explain KUD983-induced anti-HRPC mechanism.

Biological effects of novel "combi-targeting" molecule and its effect on DNA repair pathway in hormone-refractory prostate cancer.

OBJECTIVE: This study aimed to investigate the biological effects of "combi-targeting" JDF12 and its effect on the DNA repair pathway in hormone-refractory prostate cancer (HRPC). METHODS: HRPC cell lines (PC3 cells and VCap cells) were treated with JDF12 at different concentrations, and SRB method was employed to detect the proliferation of HRPC cells; Annexin V-FITC kit was used to detect the apoptosis of PC3 cells; Alkaline comet assay was performed to detect DNA damage; Western blot assay was done to detect the expressions of autophosphorylated EGFR, XRCC1 and ERCC1 (later two are proteins in DNA repair pathway); the anti-tumor effect was evaluated in nude mice inoculated with PC3 cells. RESULTS: JDF12 could inhibit the proliferation of PC3 cells and VCap cells in a concentration dependent manner (IC50: 14.04 ± 1.22 for PC3 and 15.57 ± 1.13 for VCap) and significantly increase the apoptotic cells as compared to those treated with mitozolomide or iressa alone. In PC3 cells, JDF12 induced DNA damage and also inhibited the expressions of phosphorylated EGFR, XRCC1 and ERCC1 in a concentration dependent manner. Moreover, JDF12 markedly inhibited tumor growth in nude mice. CONCLUSION: The novel "combi-targeting" JDF12 may exert more potent anti-proliferative effect as compared to mitozolomide or iressa alone, and the inhibitory effect on the EGFR signaling pathway and down-regulated XRCC1 and ERCC1 expressions may be ascribed to the JDF12 induced DNA damage.

Paradoxical and contradictory effects of imatinib in two cell line models of hormone-refractory prostate cancer.

BACKGROUND: Imatinib mesylate is a chemotherapeutic drug that inhibits the tyrosine kinase activity of c-KIT and has been successfully used to treat leukemias and some solid tumors. However, its application for treatment of hormone-refractory prostate cancer (HRPC) has shown modest effectiveness and did not follow the outcomes in cultured cells or animal models. Moreover, the molecular pathways by which imatinib induces cytotoxicity in prostate cancer cells are poorly characterized. METHODS: Two cell line models of HRPC (DU145 and PC3) were exposed to 20 µM of imatinib for 6-72 hr. MTS assay was used to assess cell viability during the course of experiment. Gene expression analysis of c-KIT, cell-cycle and apoptosis regulators, and angiogenic factors was determined by means of real-time PCR, western blot, and/or immunocytochemistry. The enzymatic activity of the apoptosis effector, caspase-3, was determined by a colorimetric assay. RESULTS: Imatinib significantly decreased the viability of DU145 cells but paradoxically augmented the viability of PC3 cells. DU145 cells displayed diminished expression of anti-apoptotic Bcl-2 protein and augmented levels of caspase-8 and -9, as well as, increased enzymatic activity of caspase-3 in response to imatinib. No differences existed on the expression levels of apoptosis-related proteins in PC3 cells treated with imatinib, though the activity of caspase-3 was decreased. The mRNA levels of angiogenic factor VEGF were decreased in DU145-treated cells, whereas an opposite effect was seen in PC3. In addition, it was shown that DU145 and PC3 cells present a differential expression of c-KIT protein variants. CONCLUSION: DU145 and PC3 cells displayed a contradictory behavior in response to imatinib, which was underpinned by a distinct expression pattern (or activity) of target regulators of cell-cycle, apoptosis, and angiogenesis. The paradoxical effect of imatinib in PC3 cells may be related with the differential expression of c-KIT protein variants. Moreover, the present findings helped to understand the discrepancies in the efficacy of imatinib as therapeutic option in HRPC.

TroVax in colorectal cancer.

Currently, the backbone of therapy for metastatic disease is cytotoxic chemotherapy, along with the recent addition of targeted therapy based on molecular markers with KRAS testing. Despite the improvement in survival for metastatic colon cancer, newer agents are still needed. The clinical activity of TroVax in metastatic colon cancer has been studied in a small number of clinical trials. There is evidence that supports the vaccine's ability to induce humoral and cellular responses, as demonstrated by positive 5T4 and MVA-specific antibody titers and cellular proliferation assays. Future strategies should focus on investigating the immunomodulatory effects of chemotherapy in conjunction with TroVax, understanding the optimal dosing and schedule of the combination, and examining potential predictive biomarkers to determine which patients may benefit from immunotherapy from those who do not.

[Management of enzalutamide, a new hormonal therapy]. / Enzalutamide, modalités pratiques d'utilisation d'une nouvelle hormonothérapie.

Enzalutamide (MDV3100) is a non-steroidal antiandrogen of second generation that has shown efficacy in metastatic castration-resistant prostate cancer (mCRPC). The study AFFIRM demonstrated a statistically significant increase in overall survival among patients who have progressed following a docetaxel chemotherapy. Based on these results, a marketing authorization for enzalutamide has been granted. The enzalutamide has been shown to be generally well tolerated. Other trials are underway to evaluate its earlier use in the management of mCRPC. A pivotal registration phase III study (PREVAIL) is ongoing to investigate the effectiveness of enzalutamide in patients who have not yet received chemotherapy.

Clinical trial risk in castration-resistant prostate cancer: immunotherapies show promise.

OBJECTIVES: To determine the risk of failure during drug development in castration-resistant prostate cancer (CRPC) and to identify factors that could improve outcomes. METHODS: We investigated CRPC by analysing compounds in phase I to phase III clinical trials between 1998 and April 2011. Drug development failures were classified as medical or commercial and were compared with industry expectations. Compounds were excluded from analysis if their phase I occurred before 1998, if they targeted patients that were did not have hormone-refractory prostate cancer, or if they did not assess outcomes such as overall survival, time to disease progression, or prostate-specific antigen levels. RESULTS: Thorough searches of clinicaltrial.gov and other databases yielded 77 compounds that met the inclusion criteria. The cumulative pass rate for first-line compounds in CRPC was 3% and was far below aggregate industry expectations. In total, there were nearly equivalent numbers of commercial and medical failures. Biological products were found to have had greater relative success than small-molecule drugs and biotechnology firms had been slightly more successful than pharmaceutical firms in this disease indication. Phase III failures were high, despite equally high failures during phase II. CONCLUSIONS: Currently, one in 33 compounds that enters clinical testing will be awarded US Food and Drug Administration approval. This appears to be the highest risk indication investigated to date, based on clinical trial studies alone, with an average cost of $1.411bn to bring a new drug to market when adjusted for risk. Development of radical therapeutics such as immunotherapies may also be warranted instead of classic antineoplastic therapeutics. Given the high clinical trial risk, efforts may have to shift to biomarker and surrogate endpoints to manage future clinical trial risk in prostate cancer.

Radiotherapy and concurrent metronomic chemotherapy in hormone-refractory prostate carcinoma: a Phase I study.

AIM: To determine the maximum tolerated dose of hypofractionated radiotherapy (HFRT) plus concurrent metronomic chemotherapy in patients with hormone-refractory prostate cancer (HRPC). PATIENTS AND METHODS: A Phase I clinical trial was performed with cohorts of three to six patients per group. Eligible patients had HRPC without distant metastases. The radiotherapy dose was escalated in a stepwise fashion as follows: 60, 65, and 70 Gy at levels 1, 2, and 3, respectively (25 fractions: levels 1-2, and 26 fractions: level 3). RESULTS: Nine patients were enrolled. The radiotherapy dose was escalated from 60 to 70 Gy without any dose-limiting toxicity. The most common grade 1/2 toxicities were hematuria, dysuria, diarrhea and rectal-perirectal pain. The overall objective response rate was 9/9 (100%) (95% CI=66.4%-100%). The median time-to-progression was 19 months. CONCLUSION: In the challenging setting of HRPC, HFRT up to 70 Gy with concurrent metronomic chemotherapy was well-tolerated and yielded encouraging disease control.

Green tea polyphenol epigallocatechin-3-gallate (EGCG) as adjuvant in cancer therapy.

BACKGROUND & AIMS: Green tea catechins, especially epigallocatechin-3-gallate (EGCG), have been associated with cancer prevention and treatment. This has resulted in an increased number of studies evaluating the effects derived from the use of this compound in combination with chemo/radiotherapy. This review aims at compiling latest literature on this subject. METHODS: Keywords including EGCG, cancer, chemotherapy, radiotherapy and side effects, were searched using PubMed and ScienceDirect databases to identify, analyze, and summarize the research literature on this topic. Most of the studies on this subject up to date are preclinical. Relevance of the findings, impact factor, and date of publication were critical parameters for the studies to be included in the review. RESULTS: Additive and synergistic effects of EGCG when combined with conventional cancer therapies have been proposed, and its anti-inflammatory and antioxidant activities have been related to amelioration of cancer therapy side effects. However, antagonistic interactions with certain anticancer drugs might limit its clinical use. CONCLUSIONS: The use of EGCG could enhance the effect of conventional cancer therapies through additive or synergistic effects as well as through amelioration of deleterious side effects. Further research, especially at the clinical level, is needed to ascertain the potential role of EGCG as adjuvant in cancer therapy.

PXD101 potentiates hormonal therapy and prevents the onset of castration-resistant phenotype modulating androgen receptor, HSP90, and CRM1 in preclinical models of prostate cancer.

Aberrant activation or 'reactivation' of androgen receptor (AR) during androgen ablation therapy shows a potential cause for the development of castration-resistant prostate cancer. This study tested the hypothesis that PXD101, a potent pan histone deacetylase (HDAC) inhibitor, may prevent onset of castration-resistant phenotype and potentiate hormonal therapy. A panel of human prostate cancer cells with graded castration-resistant phenotype and in vivo models were used to verify this hypothesis. In this report, we demonstrated that hormonal manipulation favors the onset of castration-resistant phenotype increasing HDAC expression and activity as well as modulating expression and activity of AR, EGFR, HER2, and Akt. Consistent with these observations, the functional knockdown of HDACs by PXD101 prevented the onset of castration-resistant phenotype with a significant downregulation of AR, EGFR, HER2, and Akt expression/activity. The dysregulation of functional cooperation between HDAC6 with hsp90, on the one hand, and between GSK-3ß with CRM1, on the other hand, may explain the biological effects of PXD101. In this regard, the HDAC6 silencing or the functional knockdown of hsp90 by 17AAG resulted in the selective downregulation of AR, EGFR, HER2, and Akt expression/activity, while the decreased phosphorylation of GSK-3ß mediated by PXD101 increased the nuclear expression of CRM1, which in turn modified the AR and survivin recycling with increased caspase 3 activity. HDAC inhibitors retain the ability to prevent the onset of castration-resistant phenotype and, therefore, merit clinical investigation in this setting. However, additional data are needed to develop clinical treatment strategies for this disease stage.

Nonsteroidal androgen receptor ligands: versatile syntheses and biological data.

We report herein a stereoselective and straightforward methodology for the synthesis of new androgen receptor ligands with (anti)-agonistic activities. Oxygen-nitrogen replacement in bicalutamide-like structures paves the way to the disclosure of a new class of analogues, including cyclized/nitrogen-substituted derivatives, with promising antiandrogen (or anabolic) activity.

Prognosic analysis of chemotherapy for patients with castration resistant prostate cancer / 中华泌尿外科杂志

Objective To analyze prognosic factors for patients with hormone refractory prostate cancer (HRPC) after chemotherapy of docetaxel/mitoxantrone plus prednisone and to explore the relationship between prostate specific antigen (PSA) parameters and prognosis. Methods Data from 68 patients with CRPC after chemotherapy were collected and analyzed retrospectively.The median age of these patients were 65 years old with 28 cases of biopsy Gleason score ＜ 8 and 35 cases of ≥ 8.The median serum PSA at diagnosis,nadir and pre-chemotherapy baseline were 142 ng/ml,0.5 ng/ml and 33.0 ng/ml,respectively.There were 38 patients in docetaxel group and 30 in mitoxantrone group.PSA doubling time ( PSADT),progression free survival (PFS) and overall survival (OS) was calculated.Chi square test was used in analysis of chemotherapy effect and Cox proportional hazards regression model was applied to identify the predictors for PFS and OS.The median value of continuous variable as cutoff point was used to divide patients into two groups to compare.Risk ratio and 95％ confidence interval (CI) was calculated. Results 38 (55.9％)patients experienced effective chemotherapy. The effective rate were 33％ and 74％ for PSADT ＜ 1.6 months and ≥ 1.6 months group,85％ and 49％ for M0 and M1 stage group,and 69％ and 40％ for docetaxel and mitoxantrone group,(P ＜ 0.05).The median PFS was (3.5 ± 0.5) months for all patients,which were (2.7 ±0.4) months and (5.9 ±0.6) months for patients with PSADT ＜ 1.6 months and ≥ 1.6 months group,(5.0 ± 0.6) months and (2.7 ± 0.5 ) months for patients with docetaxel and mitoxantrone group,and (5.7 ± 0.8) months and ( 3.4 ± 0.6) months for patients with Gleason score ＜ 8 and ≥ 8 group (P ＜0.05).26 case died in the end and the median OS was (28.3 ± 2.6) months for these patients,which were (15.7 ± 3.4) months and (31.6 ± 1.2) months for patients with PSADT ＜ 1.6 months and ≥1.6 months group,(29 ± 4.1 ) months and (28 ± 3.2) months for patients with docetaxel and mitoxantrone group,and (28.7 ± 2.6) months and (24.3 ± 5.6) months for patients with Gleason score ＜ 8 and ≥ 8 group (P ＜ 0.05). Conclusions The effective rate of chemotherapy was related with PSADT,chemotherapy strategy and M stage.PSADT,chemotherapy strategy and Gleason score may be independent predictors for patients with HRPC taking chemotherapy.Patients with PSADT ≥ 1.6 months,docetaxel chemotherapy and Gleason score ＜ 8 will have longer PFS and OS.

Efficacy and safety of docetaxel plus prednisolone chemotherapy for metastatic hormone-refractory prostate adenocarcinoma: single institutional study in Korea.

PURPOSE: To assess the efficacy and safety of treating Korean patients with metastatic hormone-refractory prostate cancer (HRPC) using docetaxel plus prednisolone chemotherapy. MATERIALS AND METHODS: This was a retrospective cohort study performed in 98 patients with metastatic HRPC between October 2003 and April 2008. After screening, 72 patients fit the eligibility criteria for inclusion in this study. Treatment consisted of 5 mg prednisolone twice daily and 75 mg/m² docetaxel once every 3 weeks. RESULTS: Patient demographic characteristics included: median age 67 years (range, 51~86), median ECOG performance status 1 (0~2), Gleason score ≥8 in 61 patients (86%), and median serum PSA 45.5 ng/mL (range, 3.7~2,420.0). A total of 405 cycles of treatment were administered with a median 6 cycles (range, 1~20) per patient. The median docetaxel dose-intensity was 24.4 mg/m(2)/week (range, 17.5~25.6). A PSA response was seen in 51% of 63 evaluable patients at 12 weeks and maximal PSA decline ≥50% in 59% of 70 evaluable patients. Tumor response was evaluated in 13 patients, 4 patients achieved PR, and 5 patients had SD with a response rate of 31%. With a median follow-up duration of 23.1 months (95%CI, 16.7~29.5), the median time to PSA progression was 5.1 months (95%CI, 4.5~5.8) and median overall survival was 22.8 months (95%CI, 16.6~29.1). Nine (13%) patients experienced grade 3 or higher febrile neutropenia. CONCLUSION: This chemotherapy regimen (docetaxel every 3 weeks plus prednisolone daily) demonstrated a strong response in Korean patients with metastatic HRPC, while the toxicity profile was manageable and similar to that observed in Western patients.

Marked leukocytosis in response to estramustine phosphate in a hormone-refractory prostate cancer patient.

A 67-year-old man was refered to our institution with a complaint of elevated serum prostate-specific antigen (PSA) level (54 ng/mL). Diagnosis was adenocarcinoma of the prostate with a Gleason score of 9, with bone metastasis (stageD2). He was treated with maximal androgen blockade followed by estramustine phosphate (EMP) because of the progression to hormone-refractory prostate cancer (HRPC). Leukocytosis over 20000/µL was repeatedly observed at each administration of EMP. This is the first case report of leukocytosis in response to EMP in an HRPC patient. The present case suggests that EMP could modulate leukocyte differentiation in HRPC patients.