Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The non-steroidal antiandrogens flutamide (Eulexin((R))), nilutamide (Anandron((R))) and bicalutamide (Casodex((R))) are widely used in the treatment of advanced prostate cancer, particularly in combination with castration. The naturally occurring ligand 5alpha-DHT has higher binding affinity at the androgen receptor than the non-steroidal antiandrogens. Bicalutamide has an affinity two to four times higher than 2-hydroxyflutamide, the active metabolite of flutamide, and around two times higher than nilutamide for wild-type rat and human prostate androgen receptors. Animal studies have indicated that bicalutamide also exhibits greater potency in reducing seminal vesicle and ventral prostate weights and inhibiting prostate tumour growth than flutamide. Although preclinical data can give an indication of the likely clinical activity, clinical studies are required to determine effective, well-tolerated dosing regimens. As components of combined androgen blockade (CAB), controlled studies have shown survival benefits of flutamide plus a luteinising hormone-releasing hormone analogue (LHRH-A) over LHRH-A alone, and for nilutamide plus orchiectomy over orchiectomy alone. Other studies have failed to show such survival benefits, including those comparing flutamide plus orchiectomy with orchiectomy alone, and nilutamide plus LHRH-A with LHRH-A alone. In a direct comparative study, bicalutamide (50 mg, once daily) was compared with flutamide (250 mg, three times daily), each in combination with an LHRH-A. Both therapies were well tolerated, although more patients could not tolerate flutamide therapy: 25 flutamide plus LHRH-A and 2 bicalutamide plus LHRH-A patients withdrew from therapy due to diarrhoea. There were no statistically significant differences for time to progression or survival between the two antiandrogens. This clinical trial of bicalutamide confirms the prediction from preclinical studies that a 50 mg dose of bicalutamide would be appropriate for use in patients with advanced prostate cancer, and demonstrates that this bicalutamide dose is clinically effective when administered as part of CAB.
Prostate Cancer Prostatic Dis 1998 Dec
PMID:Receptor affinity and potency of non-steroidal antiandrogens: translation of preclinical findings into clinical activity. 1249 72

The mainstay of hormonal therapy in prostate cancer has been medical or surgical castration, both of which are associated with loss of libido and impotence, and may not always be acceptable to the patient. Antiandrogen monotherapy is an alternative treatment option to castration. There are two types of antiandrogen, i.e. steroidal (cyproterone acetate, CPA), and nonsteroidal (bicalutamide, flutamide and nilutamide). Data comparing survival outcome with CPA and castration are limited and conflicting. Furthermore, CPA is associated with loss of libido and erectile dysfunction. Large phase III trials have established that monotherapy with bicalutamide 150 mg once daily provides a survival outcome that is not significantly different to that after castration in men with locally advanced, non-metastatic disease, while conferring significant advantages for sexual interest and physical capacity. Current data are inadequate to draw conclusions on the comparative efficacy of flutamide and castration, while nilutamide is not licensed for monotherapy. Recent data reveal that bicalutamide 150 mg given once daily in addition to standard care (radical prostatectomy, radiotherapy or 'watchful waiting') significantly delays the progression of early (localized or locally advanced) prostate cancer. Bicalutamide has a more favourable side-effect profile than the other antiandrogens and is more likely to promote compliance.
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PMID:The role of antiandrogen monotherapy in the treatment of prostate cancer. 1451 Oct 60

Osteoporosis is an important and preventable adverse effect of androgen deprivation therapy for prostate cancer. Androgen deprivation therapy by either bilateral orchiectomies or administration of a gonadotropin-releasing hormone agonist decreases bone mineral density and increases fracture risk. Treatment-related osteoporosis can be prevented by intermittent administration of either intravenous pamidronate or zoledronic acid. Pamidronate (60 mg intravenously every 3 months) prevents bone loss during androgen deprivation therapy. Zoledronic acid (4 mg intravenously every 3 months) not only prevents bone loss but also increases bone mineral density. Alendronate and other oral bisphosphonates may be effective but have not been evaluated in men with castrate testosterone levels. Oestrogen replacement therapy and treatment with selective ooestrogen receptor modulators may prevent bone loss during androgen deprivation therapy. Bicalutamide (150 mg daily) monotherapy increases serum ooestrogen levels and maintains bone mineral density.
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PMID:Management of treatment-related osteoporosis in men with prostate cancer. 1278 15

Antiandrogens such as Casodex (Bicalutamide) are designed to treat advance stage prostate cancer by interfering with androgen receptor-mediated cell survival and by initiating cell death. Treatment of androgen sensitive, non-metastatic LNCaP human prostate cancer cells with 0-100 microM Casodex or 0-10 ng/ml TNF-alpha induces cell death in 20-60% of the cells by 48 h in a dose-dependent manner. In cells treated with TNF-alpha, this is accompanied by the loss of mitochondrial membrane potential (DeltaPsim) and cell adhesion. In contrast, cells treated with Casodex display loss of cell adhesion, but sustained mitochondrial dehydrogenase activity. Overexpression of Bcl-2 in LNCaP cells attenuates the induction of cell death by TNF-alpha but not Casodex, suggesting that mitochondria depolarization is not required for the induction of cell death by Casodex. While both TNF-alpha and Casodex-induced release of cytochrome c in LNCaP cell is predominantely associated with the translocation and cleavage of Bax, our data also suggest that Casodex induces cell death by acting on components downstream of decline of DeltaPsim and upstream of cytochrome c release. Furthermore, while induction of both caspase-3 and caspase-8 activities are observed in TNF-alpha and Casodex-treated cells, a novel cleavage product of procaspase-8 is seen in Casodex-treated cells. Taken together, these data support the hypothesis that Casodex induces cell death by a pathway that is independent of changes in DeltaPsim and Bcl-2 actions and results in an extended lag phase of cell survival that may promote the induction of an invasive phenotype after treatment.
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PMID:Antiandrogen-induced cell death in LNCaP human prostate cancer cells. 1281 59

Adjuvant hormonal therapy has been demonstrated to be able to delay disease progression in nonmetastatic prostate cancer. To date, however, a favorable impact on survival has only been demonstrated in lymph-node-positive disease and in external-beam radiotherapy series with locally advanced and probably mainly micrometastatic tumors. The Bicalutamide Early Prostate Cancer Program is the largest study under way to define the role of adjuvant treatment in early prostate cancer and identify subgroups of patients likely to benefit from immediate hormonal therapy. At the time of the most recently published analysis, the risk of objective clinical progression was significantly reduced in the bicalutamide arm (hazards ratio 0.58, 95% confidence interval 0.51-0.66, p < 0.0001). However, further maturation of data is needed to see whether this difference will lead to a survival advantage.
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PMID:Adjuvant hormonal treatment for prostate cancer: the bicalutamide early prostate cancer program. 1294 26

Prostate cancer most often metastases to regional lymph nodes and bones by hematogeneous or lymphatic spread. The authors present a rare case of metastatic prostate cancer to supradiaphragmatic lymph nodes that were detected on 201Tl and 99mTc-MIBI imaging and confirmed on a CT scan. An 81-yr-old man with bilateral painful cervical lymphadenopathies was referred to our hospital with suspected thyroid cancer. The US and thyroid scan indicated no abnormalities in his thyroid gland. Both 201Tl and 99mTc-MIBI scans showed multiple areas of abnormally increased radioactivity in both supraclavicular, anterior mediastinum, and bilateral hilar regions. A CT scan also revealed multiple lymphadenopatheis in the same regions as radionuclide scans. Prostate cancer was diagnosed from the results of immunohistochemical staining for PSA examination of a biopsy specimen of the mediastinal lymph node. The serum PSA concentration was markedly elevated at 490 ng/ml (normal, < 40 ng/ml). Both 99mTc-HMDP bone and 67Ga scans were normal. All supradiaphragmatic lymph nodes on CT images disappeared 2 months after subcapsular orchiectomy and endocrine treatment with Bicalutamide. Metastatic prostate cancer should be considered when metastatic adenocarcinoma is discovered in the supraclavicular lymph nodes of elder men.
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PMID:[A case report of distant lymph nodes metastases from prostate cancer imaged with 201Tl and 99mTc-MIBI]. 1473 8

Bicalutamide is a nonsteroidal pure antiandrogen given at a dosage of 150 mg once daily as monotherapy for the treatment of early (localised or locally advanced) nonmetastatic prostate cancer. It is used at a dosage of 50 mg once daily in combination with a luteinising hormone-releasing hormone analogue or surgical castration for the treatment of advanced prostate cancer. Bicalutamide is a racemate and its antiandrogenic activity resides almost exclusively in the (R)-enantiomer, with little, if any, activity in the (S)-enantiomer. (R)-Bicalutamide is slowly and saturably absorbed, but absorption is unaffected by food. It has a long plasma elimination half-life (1 week) and accumulates about 10-fold in plasma during daily administration. (S)-Bicalutamide is much more rapidly absorbed and cleared from plasma; steady-state concentrations (Css) of (R)-bicalutamide are 100-fold higher than those of (S)-bicalutamide. Css increases linearly with doses up to 50 mg, but nonlinearly at higher doses, reaching a plateau above 300 mg. Css is higher in Japanese than in Caucasians, but no relationship with degree of renal impairment, bodyweight or age exists. Although mild-to-moderate hepatic impairment does not affect pharmacokinetics, there is evidence for slower elimination of (R)-bicalutamide in subjects with severe hepatic impairment. Bicalutamide metabolites are excreted almost equally in urine and faeces with little or no unchanged drug excreted in urine; conversely, unchanged drug predominates in plasma. Bicalutamide in faeces is thought to arise from hydrolysis of bicalutamide glucuronide and from unabsorbed drug. Bicalutamide appears to be cleared almost exclusively by metabolism; this is largely mediated by cytochrome P450 (CYP) for (R)-bicalutamide, but glucuronidation is the predominant metabolic route for (S)-bicalutamide. (S)-Bicalutamide is metabolised in vitro by CYP3A4, and it is probable that this isoenzyme is also responsible for the metabolism of (R)-bicalutamide. In vitro data suggest that (R)-bicalutamide has the potential to inhibit CYP3A4 and, to a lesser extent, CYP2C9, 2C19 and 2D6. However, using midazolam as a specific CYP3A4 marker, no clinically relevant inhibition is observed in vivo with bicalutamide 150mg. Although bicalutamide is a CYP inducer in laboratory animals, dosages < or = 150 mg/day have shown no evidence of enzyme induction in humans. Daily administration of bicalutamide increases circulating levels of gonadotrophins and sex hormones; although testosterone increases by up to 80%, concentrations in most patients remain within the normal range. Bicalutamide produces a dose-related decrease in prostate-specific antigen (PSA) at dosages < or = 150 mg/day. However, little relationship is observed between median PSA reduction and (R)-bicalutamide Css.
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PMID:Bicalutamide: clinical pharmacokinetics and metabolism. 1550 84

Bicalutamide is a non-steroidal anti-androgen commonly used in the treatment of prostate carcinoma. We analysed the transcriptional response to bicalutamide treatment with the aim of explaining the inhibition of telomerase in the androgen-sensitive cell line LNCaP and the effects of bicalutamide on the androgen-insensitive cell line DU145. Cells treated with 80 muM bicalutamide in steroid-depleted medium for 1 day were analysed in duplicate by Affymetrix Human Genome Focus Arrays. Response to bicalutamide in LNCaP cells was represented by downregulation of androgen-regulated genes, activation of the p53 pathway and inhibition of telomerase, which was associated with downregulation of v-myc avian myelocytomatosis viral oncogene homologue (MYC) and telomerase reverse transcriptase subunit. In DU145 cells we observed the influence of cell density on bicalutamide effectivity such that highly confluent cells showed lesser sensitivity than low confluent ones. In conclusion, we provide an explanation for telomerase inhibition after androgen receptor blockade in LNCaP cells and we also report activation of the p53 pathway in LNCaP cells and in-vitro sensitivity to bicalutamide of low confluent androgen-insensitive DU145 cells. These findings might have implications for both experimental and clinical research into prostate cancer. In particular, activation of the p53 pathway after treatment with 80 microM bicalutamide could justify usage of bicalutamide dosages higher than 150 mg daily in androgen-sensitive carcinoma therapy.
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PMID:Microarray analysis of bicalutamide action on telomerase activity, p53 pathway and viability of prostate carcinoma cell lines. 1563 97

Combination therapy consists of castration plus an antiandrogen. Following medical or surgical castration, the androgen receptor can be activated by adrenal androgens, low levels of residual testosterone, and ligand-independent activators. The survival benefit of combination therapy compared with castration alone is one of the most studied questions in urology. Results from trials comparing combination therapy to castration alone are variable. A metaanalysis of 26 randomized trials indicated that the type of antiandrogen used is relevant. Combination therapy using nonsteroidal antiandrogens was associated with a statistically significant overall survival benefit. In contrast, combination therapy using steroidal antiandrogens was associated with reduced survival compared with castration alone. Bicalutamide 50 mg has a number of advantages compared with nilutamide and flutamide when used in combination with castration. These include an improved side-effect profile, once-daily dosing, more potent inhibition of androgen-independent activation of the androgen receptor through favorable interactions with nuclear coactivators and corepressors, and evidence for improved survival in one randomized trial. An analysis combining historic trial data suggests that bicalutamide 50 mg in addition to androgen deprivation may reduce the hazard ratio (HR) for prostate cancer mortality by 20% (HR, 0.80; 95% CI, 0.66-0.98).
Clin Prostate Cancer 2005 Mar
PMID:Combined androgen blockade: the case for bicalutamide. 1588 77

A round table meeting was held to discuss the role of hormonal therapy in localised prostate cancer. The findings of the group were that immediate hormonal therapy does not provide an overall survival advantage in localised and locally advanced prostate cancer. Bicalutamide can prolong disease free survival in patients with locally advanced prostate cancer, however it is important to underline that at this time it has not been shown to influence disease specific nor overall survival. It remains also unproven that early treatment is superior to treatment at progression. However, a trend towards decreased survival with bicalutamide was observed in low risk patients such as those with localised disease. In patients receiving bicalutamide, there were increased cardiovascular side-effects, in addition to the high incidence of gynaecomastia. Early hormonal therapy has to be balanced against such side-effects and the inevitable appearance of hormone refractory disease in patients who progress after hormonal therapy. Consequently, patients with localised, low risk disease are not considered appropriate candidates for hormonal therapy used either as mono-therapy or in the adjuvant setting.
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PMID:Risks and benefits of hormonal manipulation as monotherapy or adjuvant treatment in localised prostate cancer. 1625 9


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