Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the treatment of advanced prostate cancer, androgen ablation has proven to be the cornerstone. Several important questions about its use, however, remain unanswered. The first question is whether androgen ablation should be started at the time of diagnosis, or when symptoms arise. Although previous evidence had suggested no benefit to early therapy, a recent large trial of patients has shown clear benefit. Patients with locally advanced and asymptomatic metastatic disease were randomly assigned to early treatment, or treatment started at signs of progression: the early treatment group showed benefit in time to progression, incidence of severe complications, and time to death. The other major unresolved issue is the type of androgen ablation to be used. Maximal androgen blockade (MAB) has been shown to increase the survival of patients with metastatic disease in a least two large, well-conducted trial, although other trials have contradicted this finding. A recent meta-analysis of 22 MAB trials containing more than 5000 patients has suggested that MAB does not prolong life. A large trial by the National Cancer Institute (NCI) NCI INT-0105, from which preliminary results are now available, has shown that castration and an antiandrogen is no better than castration alone in terms of time to progression and survival. This trial, furthermore, did not find that MAB was superior in low-volume, good-performance status patients. Androgen ablation is not a cure for advanced prostate cancer, but it does provide excellent palliation. New treatment regimens, and new studies, are needed to optimize treatment for these men.
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PMID:A review of hormonal treatment in advanced prostate cancer. 1273 38

A diversity of bone pathology is present in men with prostate cancer. Androgen deprivation therapy (ADT) can cause significant and progressive osteopoenia and osteoporosis. Bone is also the primary site for metastases leading to associated pain, skeletal fractures and hypercalcaemia. Bisphosphonate therapy decreases bone resorption, which may prevent or reverse loss of bone mineral density. Both pamidronate and zoledronic acid have proven efficacy in preventing ADT-induced bone loss. In a randomised, placebo-controlled trial, in men with hormone-refractory prostate cancer, there was a decreased incidence of skeletal- related adverse events in men receiving zoledronic acid. So far, randomised trials have failed to show improved pain control. Formalised guidelines are needed to help clinicians decide which patients should be treated with bisphosphonates, when to initiate therapy and for what duration.
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PMID:Therapeutic benefit of bisphosphonates in the management of prostate cancer-related bone disease. 1273 96

Androgen action is mediated through androgen receptor (AR), which appears to undergo structural and functional alterations during prostate cancer (CaP) progression. AR mutations have been infrequently reported in CaP before hormonal therapy, but in untreated, advanced tumors AR mutations are suggested to be more common. To investigate the frequency of AR mutations in aggressive CaP before hormonal therapy, we have analyzed AR coding region for aberrations in 21 paraffin-embedded prostate carcinoma samples (14 primary tumors, 7 metastases) of poor histologic differentiation. Single-stranded conformational polymorphism and sequencing analyses revealed AR missense mutations in 29% (4/14) of the primary tumors and in one (14%) metastasis. Mutations resided in the transactivation domain and in the hinge region. One of the hinge region mutants, Ser646Phe, that was identified in a patient with short endocrine therapy response, exhibited a markedly increased transcriptional activity on single androgen response element-containing promoters. In conclusion, AR mutations are frequent in high-grade CaP before initiation of hormonal therapy, and these mutations may play a role in poor therapy response and emergence of hormone-refractory CaP in some cases.
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PMID:Androgen receptor mutations in high-grade prostate cancer before hormonal therapy. 1469 Dec 88

Androgen deprivation therapy (ADT) plays a central role in the management of prostate cancer. ADT is the mainstay of treatment for metastatic disease; the most common method is gonadal suppression via luteinizing hormone release hormone (LH) agonists, with or without antiandrogens. Antiandrogen monotherapy remains investigational, as is the appropriate role of 5alphareductase inhibition for prostate cancer. Intermittent ADT offers the promise of improved quality of life and reduced cost without a decrease found to date in oncologic efficacy. A growing menu of options exists for secondary androgen deprivation after disease progression on primary therapy: these include high-dose antiandrogens, estrogens, and adrenal androgen suppressants. ADT is being used with increasing frequency as primary monotherapy in patients with localized disease, but only small, nonrandomized studies of highly selected patients have been reported to date. Neoadjuvant ADT (NADT) has been demonstrated in prospective, multi-institutional trials to improve outcomes for patients with high-risk or locally advanced disease undergoing external-beam radiotherapy. Trials for patients with lower-risk, localized disease are still ongoing. Neoadjuvant therapy does not improve outcomes for patients with localized disease opting for radical prostatectomy (RP) and has not been well studied in association with brachytherapy. The side effects of ADT can be managed increasingly successfully; in particular, the introduction of zoledronate may reduce the impact of ADT-associated osteoporosis. Finally, contemporary practice pattern data suggest that use of ADT is increasing across patient risk groups, both in contexts where such therapy is well supported by current evidence and in others where it is not.
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PMID:The evolving role of androgen deprivation therapy in the management of prostate cancer. 1476 15

Skeletal complications are a major cause of morbidity in men with metastatic prostate cancer. Bone metastases cause pain, fractures, spinal-cord compression, and ineffective hematopoiesis. Men without bone metastases are also at risk for skeletal complications. Androgen deprivation therapy (ADT), the mainstay of treatment for metastatic prostate cancer and a routine part of the management for many men with nonmetastatic prostate cancer, decreases bone mineral density, and increases fracture risk. Pathological osteoclast activation plays a central role in both disease and treatment-related skeletal morbidity. Bisphosphonates, potent inhibitors of osteoclast activity, are now an important part of the management for many men with prostate cancer. Zoledronic acid, a potent intravenous bisphosphonate, decreases the risk of skeletal complications in men with hormone-refractory prostate cancer and bone metastases. Zoledronic acid and pamidronate preserve bone mineral density in men receiving ADT for nonmetastatic prostate cancer. Ongoing clinical trials will evaluate the role of osteoclast-targeted therapy in other settings including prevention of treatment-related fractures, prevention of bone metastases in men with high-risk nonmetastatic prostate cancer, and prevention of skeletal complications in men with hormone-sensitive metastatic disease.
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PMID:Osteoclast-targeted therapy for prostate cancer. 1534 75

Androgen withdrawal is the only effective therapy for patients with advanced prostate cancer, but progression to androgen independence ultimately occurs in almost all patients. Novel therapeutic strategies targeting molecular mechanisms that mediate resistance to hormonal and chemotherapeutic treatment are highly warranted. Here, we aimed to evaluate the expression of potential therapeutic targets in advanced prostate cancer. A tissue microarray (TMA) containing samples from 535 tissue blocks was constructed, including benign prostatic hyperplasia as controls (n = 65), prostatic intraepithelial neoplasia (PIN; n = 78), clinically localized prostate cancers (n = 181), as well as hormone-refractory local recurrences (n = 120) and distant metastases (n = 91). The expression of 13 different proteins was analyzed using immunohistochemistry (Bcl-2, p53, ILK, Syndecan-1, MUC-1, EGFR, HER2/neu, HSP-90, Ep-CAM, MMP-2, CD-10, CD-117 and Ki67). Significant overexpression in hormone-refractory prostate cancer and metastatic tissue compared to localized prostate cancer was found for Ki67 (64% vs. 9%), Bcl-2 (11% vs. 1%), p53 (35% vs. 4%), Syndecan-1 (38% vs. 3%), EGFR (16% vs. 1%) and HER2/neu (16% vs. 0%). Overexpression of CD-117 was restricted to 1 single metastasis. All other markers did not show relevant differences in expression between subgroups. Taken together, p53, Bcl-2, Syndecan-1, EGFR and HER2/neu are preferentially expressed in hormone-refractory and metastatic prostate cancer. Selected inhibition of these targets might offer a strategy to treat advanced tumors and prevent further progression. Treatment decisions should not be based on findings in primary tumors but rather on tissues from recurrent or metastatic lesions.
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PMID:Expression patterns of potential therapeutic targets in prostate cancer. 1547 3

Prostate cancer is the second most common cancer in men in the UK, and the incidence of prostate cancer has increased dramatically over the past two decades. Although most men are diagnosed at early stage, more than 50% develop locally advanced or metastatic disease. Androgen ablation with luteinising hormone-releasing hormone (LHRH) agonists alone, or in combination with anti-androgens, is the standard treatment for men with metastatic prostate cancer. Unfortunately, almost all men develop progressive disease after a variable time period, despite the maximal androgen blockade. The management of hormone refractory prostate cancer (HRPC) is challenging, as there is no uniformly accepted strategy. Various treatment options, including second-line hormone therapy, are discussed. Chemotherapy is being increasingly used and, importantly, docetaxel and estramustine may play an important role in the near future. The role of radiotherapy, strontium-89, bisphosphonates, novel agents and future therapies are also outlined.
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PMID:Management of patients with hormone refractory prostate cancer. 1563 Aug 42

Prostate cancer is a leading cause of morbidity and mortality among males. Androgen ablation as initial therapy for advanced prostate cancer provides high response rates but does not cure disease, as nearly all men with metastases will eventually progress to hormone-refractory prostate cancer (HRPC). Present chemotherapy regimens for HRPC can provide palliation and have recently demonstrated an increase in overall survival. Over the past 2 decades, these regimens represent clear advances in the treatment of metastatic prostate cancer but also demonstrate that newer therapies are needed. Studies are ongoing to provide viable alternatives among traditional cytotoxic therapies as well as among novel agents targeting specific molecular pathways. This article reviews some of the newer therapies being developed and evaluated, including the epothilone analogues, human epidermal growth factor receptor pathway inhibitors, angiogenesis inhibitors, and endothelin receptor antagonists.
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PMID:Newer therapies in advanced prostate cancer. 1563 81

The high morbidity and mortality associated with prostate cancer (PCa) result from its tendency to metastasize to bone where it produces predominantly osteoblastic lesions. The Wnt signaling pathway plays an important role in embryogenesis, tumorigenesis, osteoblast development, and bone formation. Androgen signaling via the androgen receptor (AR) is critical in both PCa and bone cell growth. We examined the effects of androgens on cell growth and Wnt signaling in the AR-positive MDA-PCa-2b cell line and MC3T3 preosteoblasts, grown alone and in coculture. We show that the potent androgen dihydrotestosterone increases AR expression and transcriptional activity only in the preosteoblasts. Although dihydrotestosterone induced an 80% increase in PCa cell growth when the cells were grown alone, dihydrotestosterone had a more significant effect on MDA-PCa-2b cell proliferation (3.2-fold increase) when the PCa cells were cocultured with preosteoblasts. Dihydrotestosterone addition to preosteoblasts promoted Wnt-dependent transcriptional reporter activity associated with GSK3beta(S-9) phosphorylation and accumulation of nuclear beta-catenin as well as elevated Runx2 expression. In addition, the increased proliferation of PCa cells in coculture with MC3T3 cells in response to dihydrotestosterone was abrogated by the addition of either exogenous DKK-1 or sFRP-1 protein, two naturally occurring Wnt antagonists. Finally, we show that the paracrine growth-promoting effect of androgens is limited to MDA-PCa-2b cells. These data imply that Wnt signaling is involved in the androgen-regulated crosstalk between preosteoblasts and PCa cells and suggest that androgens may stimulate growth of some prostate tumor cells indirectly, via up-regulation of Wnt signaling in bone cells.
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PMID:Androgen-induced Wnt signaling in preosteoblasts promotes the growth of MDA-PCa-2b human prostate cancer cells. 1757 41

Androgen deprivation (ADT) by medical or surgical castration represents the standard therapeutic approach for managing prostate cancer (PCA) with systemic or locoregional metastases. Although ADT has been successfully used for more than 60 years, there are still major controversies with regard to the initiation (early versus delayed), type (complete versus monotherapy), and duration (continuous versus intermittent) of treatment. It is the purpose of this review to critically present the results of the various ADT options. Bilateral orchiectomy and subcutaneous application of luteinising hormone-releasing hormone (LHRH) analogues represent the guideline-recommended standard treatment for metastatic PCA, whereas estrogens are no longer recommended because of significant cardiovascular side effects despite comparable therapeutic efficacy. Antiandrogen monotherapy with bicalutamide is comparable to LHRH analogues in men with minimal tumour burden. However, survival rates are inferior in patients with extensive metastatic disease, in whom medical or surgical castration should be favoured. Complete ADT results in a median survival benefit of about 5% in men with low metastatic tumour burden, and it cannot be recommended for routine use. Early ADT is associated with a significant advantage in terms of symptom-free survival and prevention of metastasis-associated complications, but it does not result in a prolonged progression-free and overall survival when compared with delayed ADT. Despite encouraging results, intermittent ADT remains an experimental therapeutic approach that should be considered on an individual basis in carefully selected patients. Adjuvant ADT is still discussed controversially for men after radical prostatectomy, whereas it has become the standard approach in patients who undergo external beam radiation for locally advanced PCA.
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PMID:[Androgen deprivation for advanced prostate cancer]. 1827 99


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