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1.
Clin Lung Cancer ; 16(2): 92-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25458558

RESUMO

INTRODUCTION: New treatment options are needed for second-line therapy in patients with NSCLC. PATIENTS AND METHODS: This was a phase Ib/II study in patients with nonsquamous NSCLC in whom 1 previous platinum-based chemotherapy regimen had failed. Fifteen patients were enrolled in a dose escalation of eribulin mesylate in combination with pemetrexed (E+P). In phase II (n = 80), E+P at the maximum tolerated dose was compared with P. RESULTS: In phase Ib, the maximum tolerated dose of E+P was defined as eribulin 0.9 mg/m(2) with pemetrexed (500 mg/m(2)) each on day 1 of a 21-day cycle. In phase II, adverse events were comparable between groups. PFS and OS were similar between treatment groups. Median PFS was 21.4 weeks for E+P (n = 26; 95% confidence interval [CI], 12.7-39.6) and 23.4 weeks for P (n = 29; 95% CI, 17.1-29.9), with a hazard ratio of 1.0 (95% CI, 0.6-1.7). CONCLUSION: During phase Ib, E+P was tolerated only at a markedly lower dosing intensity relative to the eribulin monotherapy regimen approved for breast cancer and used in phase II studies of NSCLC. At the selected phase II dosing regimen, E+P was generally safe and well tolerated but provided no therapeutic advantage for the second-line treatment of locally advanced or metastatic nonsquamous NSCLC.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/efeitos adversos , Antimetabólitos Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma Pulmonar de Células não Pequenas/patologia , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Feminino , Furanos/administração & dosagem , Glutamatos/administração & dosagem , Guanina/administração & dosagem , Guanina/análogos & derivados , Humanos , Cetonas/administração & dosagem , Neoplasias Pulmonares/patologia , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Pemetrexede , Taxa de Sobrevida , Resultado do Tratamento
2.
Am J Ther ; 21(6): 512-22, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24451296

RESUMO

Assessments of cardiac and cardiovascular toxicity are prominent components of drug safety endeavors during drug development and clinical practice. Oncologic drugs bring several challenges to both domains. First, during drug development, it is necessary to adapt the ICH E14 "Thorough QT/QTc Study" because the cytotoxic nature of many oncologics precludes their being administered to healthy individuals. Second, appropriate benefit-risk assessments must be made by regulators: given the benefit these drugs provide in life-threatening illnesses, a greater degree of risk may be acceptable when granting marketing authorization than for drugs for less severe indications. Third, considerable clinical consideration is needed for patients who are receiving and have finished receiving pharmacotherapy. Paradoxically, although such therapy has proved very successful in many cases, with disease states going into remission and patients living for many years after cessation of treatment, cardiotoxicities can manifest themselves relatively soon or up to a decade later. Oncologic drugs have been associated with various off-target cardiovascular responses, including cardiomyopathy leading to heart failure, cardiac dysrhythmias, thromboembolic events, and hypertension. Follow-up attention and care are, therefore, critical. This article reviews the process of benefit-risk estimation, provides an overview of nonclinical and preapproval clinical assessment of cardiovascular safety of oncology drugs, and discusses strategies for monitoring and management of patients receiving drugs with known cardiotoxicity risk. These measures include cardiac function monitoring, limitation of chemotherapy dose, use of anthracycline analogs and cardioprotectants, and early detection of myocardial cell injury using biomarkers.


Assuntos
Antineoplásicos/uso terapêutico , Cardiotoxicidade/prevenção & controle , Desenho de Fármacos , Animais , Antineoplásicos/efeitos adversos , Cardiotoxicidade/etiologia , Cardiotoxicidade/fisiopatologia , Monitoramento de Medicamentos/métodos , Humanos , Neoplasias/tratamento farmacológico , Medição de Risco/métodos , Fatores de Tempo
7.
Cancer Epidemiol Biomarkers Prev ; 17(2): 292-9, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18268112

RESUMO

BACKGROUND: Prostate cancer is a major health issue, and prevention of prostate cancer and/or its progression will yield benefits for men. Difluoromethylornithine (DFMO) is an antiproliferative agent, inhibiting ornithine decarboxylase, the first enzyme in the polyamine pathway, and has been studied as a therapeutic and chemopreventive agent. The prostate has high levels of tissue polyamines and has shown sensitivity to DFMO both in vitro and in vivo. METHODS: Eighty-one men participated in a 1-year randomized trial of placebo or DFMO. Prostate volume determination and biopsy of the prostate for histology and polyamine content were done at baseline and after 12 months. Other biomarker variables were assessed, including total and free prostate-specific antigen and prostate-specific antigen doubling time. RESULTS: Compared with baseline, men receiving DFMO had a smaller increase in prostate volume (0.14 cm(3)) than those on placebo (2.95 cm(3); P = 0.0301) at 1 year. In addition, DFMO caused a 60.8% reduction of prostate putrescine levels compared with a 139.5% increase in the placebo arm (P = 0.0014). Stratification by ornithine decarboxylase genotype showed that DFMO reduced prostate volume (P = 0.029) and putrescine levels (P = 0.0053) in the AA + GA group but not in the GG group. There were no grade 3 or 4 toxicities. There was no clinical ototoxicity, with one subclinical grade 2 hearing decline on audiogram. CONCLUSION: In this randomized placebo-controlled trial, DFMO induced a decrease of prostate putrescine levels and rate of prostate growth. The potential of this compound for prostate cancer or hyperplasia should be further studied.


Assuntos
Antineoplásicos/farmacologia , Eflornitina/farmacologia , Poliaminas/metabolismo , Próstata/efeitos dos fármacos , Neoplasias da Próstata/prevenção & controle , Adulto , Idoso , Biomarcadores Tumorais/sangue , Biópsia , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Próstata/patologia , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Estatísticas não Paramétricas
8.
Am J Ther ; 15(1): 66-81, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18223356

RESUMO

Dietary intake of lycopene is inversely associated with the risk of many cancers. Preclinical studies show that lycopene has potent in vitro and in vivo antitumor effects, suggesting potential preventive and therapeutic roles for the compound. However, clinical trials with lycopene have only recently been started, and available clinical data preclude firm conclusions with regard to its use in cancer prevention and treatment. Further mechanistic studies and randomized controlled clinical intervention trials with lycopene involving cancer patients are warranted.


Assuntos
Anticarcinógenos/farmacologia , Carotenoides/farmacologia , Neoplasias/tratamento farmacológico , Animais , Anticarcinógenos/uso terapêutico , Carotenoides/uso terapêutico , Ensaios Clínicos como Assunto , Dieta , Avaliação Pré-Clínica de Medicamentos , Humanos , Licopeno , Neoplasias/prevenção & controle
9.
Mol Cancer Ther ; 5(7): 1754-63, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16891461

RESUMO

Alteration of actin remodeling is a marker of malignant-associated field defect and a potential surrogate biomarker for chemoprevention trials. We tested erlotinib, a specific tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR), on actin remodeling in a bladder carcinogenic model consisting of untransformed HUC-PC cells and transformed MC-T11 cells, both derived from the same normal human urothelial clone immortalized by SV40. Erlotinib had a selective growth inhibitory and actin remodeling effect on MC-T11 cells over HUC-PC cells, as examined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and immunofluorescence labeling with laser scan cytometer analysis, respectively. The IC(50) of untransformed HUC-PC cells was significantly higher than that of transformed MC-T11 cells (P < 0.05, t test). The actin remodeling effect was more prominent at lower dosage levels (1/8-1/4 of IC(50)), which was accompanied by an increased cell adhesion and decreased motility. At higher dosage levels (1/2 of IC(50)), erlotinib induced a decreased adhesion and anoikis (detachment-associated apoptosis). The transformed MC-T11, but not HUC-PC, showed a weak constitutive EGFR phosphorylation activity, which was inhibited by erlotinib in a dose-response manner. However, on epidermal growth factor stimulation, both cell lines showed a similar dose-response inhibitory effect on phosphorylated EGFR and mitogen-activated protein kinase (MAPK; P44/P42) activities, and MAPK inhibitor PD98059 showed no specific effect on erlotinib-induced actin remodeling, suggesting that pathways other than MAPK (P44/P42) may be responsible for erlotinib-induced actin remodeling. The findings provide evidence to support erlotinib-based bladder cancer chemoprevention and using actin remodeling as a marker for erlotinib-based intervention trials.


Assuntos
Actinas/efeitos dos fármacos , Anticarcinógenos/farmacologia , Transformação Celular Neoplásica/efeitos dos fármacos , Receptores ErbB/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/farmacologia , Neoplasias da Bexiga Urinária/enzimologia , Actinas/metabolismo , Anticarcinógenos/uso terapêutico , Apoptose/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Transformação Celular Neoplásica/metabolismo , Cloridrato de Erlotinib , Flavonoides/farmacologia , Humanos , Concentração Inibidora 50 , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Inibidores de Proteínas Quinases/uso terapêutico , Quinazolinas/uso terapêutico , Neoplasias da Bexiga Urinária/prevenção & controle
10.
Cancer Epidemiol Biomarkers Prev ; 15(8): 1479-84, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16896036

RESUMO

High-grade prostatic intraepithelial neoplasia (HGPIN) is generally regarded as a premalignant lesion that progresses toward prostate cancer. In light of the significant sequelae of prostate cancer treatment, prevention is desirable, and men with HGPIN would be suitable, high-risk subjects. There is in vitro, in vivo, epidemiologic, and human experimental evidence that selenium supplementation may protect against prostate cancer. This article introduces the rationale for, and progress to date, of a double-blind, randomized, placebo-controlled trial of selenium supplementation (200 mug/d in the form of selenomethionine), to prevent the development of prostate cancer among men with HGPIN. The trial, Southwest Oncology Group Protocol 9917, funded by a National Cancer Institute program supporting pivotal prevention trials has registered 537 patients and has randomized >380 to date. Subject accrual is expected to be completed by the fall of 2006, with trial completion in 2009.


Assuntos
Anticarcinógenos/uso terapêutico , Ensaios Clínicos como Assunto/métodos , Neoplasia Prostática Intraepitelial/prevenção & controle , Neoplasias da Próstata/prevenção & controle , Selênio/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Suplementos Nutricionais , Método Duplo-Cego , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Placebos , Neoplasia Prostática Intraepitelial/epidemiologia , Neoplasias da Próstata/epidemiologia , Projetos de Pesquisa , Selênio/sangue
11.
Am J Ther ; 13(4): 291-7, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16858161

RESUMO

High-grade prostatic intraepithelial neoplasia (HGPIN) has been identified as a premalignant change in the prostate that indicates increased risk of the subsequent development of prostate adenocarcinoma. Prior studies have suggested that androgen deprivation therapy causes a regression of HGPIN. We therefore conducted a chemoprevention trial assessing the efficacy of flutamide in reducing the rate of prostate adenocarcinoma development in men with HGPIN. Men with biopsyproven HGPIN but no evidence of prostate adenocarcinoma were randomized in a double-blind manner to either flutamide 250 mg/d or a placebo. Treatment was continued for 1 year. Repeat biopsies were obtained at 12 and 24 months. Quality of life and toxicities related to treatment were also measured. Sixty patients were randomized and began therapy with either flutamide or placebo. At 1 year, 14% of men receiving flutamide and 10% of men receiving placebo had developed prostate adenocarcinoma. Flutamide-associated toxicities were mild to moderate in severity. Quality-of-life measures did not show any differences between the 2 groups. This study showed no evidence of benefit from flutamide as a chemoprevention agent in men with HGPIN.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Flutamida/uso terapêutico , Neoplasia Prostática Intraepitelial/tratamento farmacológico , Neoplasias da Próstata/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Hormonais/efeitos adversos , Método Duplo-Cego , Flutamida/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasia Prostática Intraepitelial/psicologia , Qualidade de Vida
12.
Cancer Epidemiol Biomarkers Prev ; 14(7): 1697-702, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16030104

RESUMO

BACKGROUND: Evidence of the chemopreventive effects of the dietary antioxidants alpha-tocopherol (vitamin E) and l-selenomethionine (selenium) comes from secondary analysis of two phase III clinical trials that found treatment with these antioxidants reduced the incidence of prostate cancer. To determine the effects of selenium and vitamin E in blood and prostate tissue, we undertook a preoperative feasibility study complementary to the currently ongoing Selenium and Vitamin E Cancer Prevention Trial. METHODS: Forty-eight patients with clinically localized prostate cancer enrolled on this 2 x 2 factorial design study were randomized to take selenium, vitamin E, both, or placebo for 3 to 6 weeks before prostatectomy. Sera were collected from patients before and after dietary supplementation. Thirty-nine patients were evaluable, and 29 age-matched disease-free men served as controls. Mass profiling of lipophilic serum proteins of lower molecular weight (2-13.5 kDa) was conducted, and mass spectra data were analyzed using custom-designed software. RESULTS: Weighted voting analyses showed a change in sera classification from cancerous to healthy for some patients with prostate cancer after dietary intervention. ANOVA analysis showed significantly different treatment effects on prediction strength changes among the four groups at a 95% confidence level. Eliminating an outlying value and performing post hoc analysis using Fisher's least significant difference method showed that effects in the group treated with the combination were significantly different from those of the other groups. CONCLUSION: In sera from patients with prostate cancer, selenium and vitamin E combined induced statistically significant proteomic pattern changes associated with prostate cancer-free status.


Assuntos
Antioxidantes/uso terapêutico , Neoplasias da Próstata/prevenção & controle , Selenometionina/uso terapêutico , Vitamina E/uso terapêutico , Análise de Variância , Método Duplo-Cego , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pré-Operatórios , Prostatectomia , Neoplasias da Próstata/sangue , Proteômica
13.
J Urol ; 174(2): 539-46, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16006888

RESUMO

PURPOSE: There is no current standard treatment for patients with prostate cancer who have received hormonal therapy but have an increasing prostate specific antigen (PSA) without radiographic evidence of metastasis. This trial was designed to analyze toxicity, immunogenicity and time to treatment failure using vaccine, antiandrogen therapy or their sequential use. MATERIALS AND METHODS: A total of 42 patients were randomized to receive vaccine vs antiandrogen therapy with nilutamide. The vaccine consisted of recombinant vaccinia viruses containing the PSA and B7.1 costimulatory genes as prime vaccinations, and avipox-PSA as boosters. After 6 months patients with an increasing PSA and no metastasis may receive a combination of both treatments. RESULTS: Three patients on nilutamide were removed from study secondary to grade 3 toxicities but no grade 3 toxicities were attributed to vaccine. In the vaccine arm median time to treatment failure was 9.9 months with 13 of 21 decreases in PSA velocity vs 7.6 months with 16 of 21 decreases in PSA velocity in the nilutamide arm (p =0.28). Of the patients in the nilutamide arm 8 had vaccine added at the time of PSA progression. Median time to treatment failure with combined therapy was 5.2 months, with a median duration from study entry of 15.9 months. Of the patients in the vaccine arm 12 had nilutamide added at the time of PSA progression. Median time to treatment failure with combined therapy was 13.9 months and a median of 25.9 months from initiation of therapy. CONCLUSIONS: Further studies are merited to investigate the role of combining vaccine with antiandrogen therapy or vaccine followed by vaccine plus antiandrogen therapy in this patient population.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Vacinas Anticâncer/uso terapêutico , Imidazolidinas/uso terapêutico , Neoplasias da Próstata/terapia , Idoso , Idoso de 80 Anos ou mais , Vacinas Anticâncer/química , Progressão da Doença , Humanos , Masculino , Pessoa de Meia-Idade , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/mortalidade
14.
Am J Ther ; 12(2): 172-4, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15767834

RESUMO

There is currently no standard therapy for patients with prostate cancer who have progressive rise in PSA levels despite treatment with hormonal ablation and antiandrogen withdrawal (stage D0.5). One potential treatment option is the use of a different androgen receptor antagonist (ARA), such as nilutamide. We report a case of a 66-year-old gentleman with greater than a 46 month sustained response to nilutamide therapy after failing bicalutamide therapy and its subsequent withdrawal. The patient continues to have undetectable PSA levels and an excellent performance status. This case demonstrates the prolonged response to a second-line ARA in patients deemed to have androgen insensitive prostate cancer. Further investigation of the potential role of nilutamide therapy as second-line antiandrogen therapy is warranted as monotherapy and/or in combination with other promising novel approaches including PSA-based vaccines.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Imidazolidinas/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Idoso , Anilidas/uso terapêutico , Humanos , Leuprolida/uso terapêutico , Masculino , Nitrilas , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/diagnóstico , Compostos de Tosil
15.
Clin Cancer Res ; 10(22): 7583-91, 2004 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-15569989

RESUMO

PURPOSE: Efficient strategies to screen promising agents in early phase development are essential for rapid progress in breast cancer chemoprevention. We report our experience with the natural compound perillyl alcohol (POH) administered in a short-term surrogate end point biomarker (SEB) protocol, using the "window" between diagnostic and definitive surgery. EXPERIMENTAL DESIGN: Eligible patients included those with a diagnosis of atypical ductal hyperplasia, ductal carcinoma in situ, lobular carcinoma in situ, or invasive carcinoma (<3 cm in size) that required further surgery. Thirty-seven of 267 women screened were enrolled in the study (14%). Five women received single-dose POH (1.5 g/m2) 2 days before surgery, 16 received escalating doses of POH (1.2 g/m2 to 4.8 g/m2/day) for 2 days before surgery, and 16 served as untreated controls. Exploratory SEB analysis [estrogen receptor, progesterone receptor, proliferation, apoptosis, M6P/insulin-like growth factor (IGF)-2R, IGF1, IGF2 and transforming growth factor beta] was conducted before and after POH. RESULTS: Only a small portion of the population screened entered the study. Reasons for nonparticipation included protocol ineligibility, conflict of timing of surgery, miscellaneous logistical reasons, or patient's choice. POH administration was well tolerated and did not interfere with surgical management. The power to observe changes in candidate SEB was diminished by a 44% incidence of cases in which the index lesion was not present in the definitive surgical specimen. CONCLUSIONS: Preoperative POH exposure was safe and suitable for a more definitive phase II SEB study. Further investigations must overcome logistical obstacles to accrual, and they must focus on approaches to maximize tissue collection and to incorporate genomic analysis of target lesions.


Assuntos
Antineoplásicos/uso terapêutico , Biomarcadores Tumorais , Neoplasias da Mama/tratamento farmacológico , Monoterpenos/uso terapêutico , Idoso , Apoptose , Biomarcadores , Biópsia , Neoplasias da Mama/metabolismo , Carcinoma in Situ , Carcinoma Intraductal não Infiltrante/tratamento farmacológico , Proliferação de Células , Estudos de Coortes , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Projetos Piloto , Fatores de Tempo , Resultado do Tratamento
16.
Am J Ther ; 11(6): 501-6, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15543092

RESUMO

Following FDA approval and introduction into the clinic in the mid-1980s, PSA testing has become arguably the most versatile serum tumor marker in urologic oncology with clinical use for early detection (screening) of prostate cancer (PC), risk stratification for clinical staging, prognosis, intermediate biomarker for monitoring tumor recurrence, and more recently as an intermediate biomarker for assessing therapeutic response to antiandrogens, radiation therapy, and chemotherapy. PSA now routinely guides health care providers for the clinical management of PC over a wide range of clinical risk states for men at risk of PC, after local definitive therapy and after systemic therapy to prevent progression to metastatic bone disease, and to palliate men with hormone refractory prostate cancer (HRPC). To further assess the evidence that supports these clinical applications, this commentary reviews and critically evaluates the emerging body of new data focusing on several recently published seminal articles by D'Amico et al and Thompson et al, the new National Comprehensive Cancer Network 2004 recommendations for starting PSA testing at the age of 40 years old, the latest results from 2 phase 3 randomized, controlled trials of taxane-based regimens showing improved survival for men with HRPC, and the recent US FDA Public Workshop on Clinical Trial Endpoints in Prostate Cancer that helped to distill and synthesize the current state of the art and the progress toward validation of PSA metrics (eg, PSA velocity) as a surrogate end point (SE) for treatment efficacy with taxane-based regimens. Furthermore, several randomized, controlled chemoprevention trials in progress evaluating agents such as selenium and vitamin E in high-risk cohorts are well poised to confirm the validity of PSA as an SE for clinical efficacy for the prevention and progression of PC. Although there continues to be a need to validate better biomarkers before diagnosis of PC (more sensitive and specific) and after diagnosis to discern between indolent and aggressive forms of PC, it is very likely that some metric of PSA as a biomarker alone or as part of a panel of other serum proteomic markers or tissue-derived multiplex gene expression arrays will be around for years to come as a useful tool for risk stratification, early detection, prognosis, prediction, and as an SE of efficacy for prevention and treatment of PC.


Assuntos
Biomarcadores Tumorais , Antígeno Prostático Específico , Neoplasias da Próstata/diagnóstico , Neoplasias Ósseas/prevenção & controle , Neoplasias Ósseas/secundário , Medicina Baseada em Evidências , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/patologia , Neoplasias da Próstata/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto , Medição de Risco
17.
J Urol ; 171(2 Pt 2): S68-74; discussion S75, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14713758

RESUMO

PURPOSE: We describe the current National Cancer Institute chemoprevention agent development program and provide a summary of the intermediate end points used. MATERIALS AND METHODS: The National Cancer Institute is currently sponsoring a wide range of studies of promising chemoprevention agents in a variety of informative cohorts, eg high grade prostatic intraepithelial neoplasia, positive family history of cancer, increased prostate specific antigen with negative biopsies, prostate cancer followed expectantly, prostate cancer awaiting definitive therapy and the general population. The rationale for each agent under investigation is derived from epidemiological observations, prostate cancer treatment trials, secondary analyses of large cancer prevention studies, an understanding of cancer biology and prostate carcinogenesis, and/or experimental animal models. RESULTS: Carcinogenesis is a multistep process occurring over decades which is characterized by disruption of the normal regulatory pathways controlling cellular proliferation, programmed cell death and differentiation. Administration of agents to reverse, inhibit or slow this process of malignant transformation is known as chemoprevention. CONCLUSIONS: Chemoprevention represents a promising approach to reducing the morbidity and mortality of prostate cancer. A variety of agents are currently being studied in phase 2 clinical trials, some of which may warrant subsequent evaluation in phase 3 trials with definitive cancer end points. Two large phase 3 trials, the Prostate Cancer Prevention Trial and the Selenium and Vitamin E Cancer Prevention Trial, which are ongoing, are also sponsored by the National Cancer Institute.


Assuntos
Anticarcinógenos/uso terapêutico , Neoplasias da Próstata/prevenção & controle , Ensaios Clínicos Controlados Aleatórios como Assunto , Biomarcadores Tumorais , Humanos , Masculino , National Institutes of Health (U.S.) , Estados Unidos
18.
Cancer Epidemiol Biomarkers Prev ; 12(11 Pt 1): 1213-21, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14652284

RESUMO

Preclinical studies suggest that the isoflavone genistein may have prostate cancer chemopreventive activity. Genistein has been shown to alter cellular levels of protein-tyrosine phosphorylation and is present at high levels in soy. This study was designed to measure the pharmacokinetic parameters of two different preparations of unconjugated soy isoflavones, PTI G-2535 and PTI G-4660 (which contain 43% and 90% genistein, respectively), in human subjects with cancer, to evaluate toxicity and obtain pilot data on in vivo effects on protein-tyrosine phosphorylation. Cohorts of four patients were given single doses of each preparation; each dose was separated by 1 week. Sequential cohorts received genistein at 2, 4, or 8 mg/kg orally. Pharmacokinetic sampling was performed after each dose, and tyrosine phosphorylation was measured in proteins extracted from peripheral blood mononuclear cells. One of 13 patients treated developed a treatment-related rash. No other toxicities were observed. Maximal plasma concentrations (C(max)) ranged between 4.3 and 16.3 micro M for total genistein and 0.066 and 0.17 micro M for free genistein. For PTI G-2535 and PTI G-4660, half-life was 15.03 and 22.41 h, respectively, and volume of distribution was 189.9 and 653.8 liters, respectively, and there was a trend toward higher area under the concentration curve for PTI G-2535 (P = 0.07 at the 8 mg/kg dose). Treatment-related increases in tyrosine phosphorylation were observed in peripheral blood mononuclear cells. Oral administration of soy isoflavones gives plasma concentrations of genistein that have been associated with antimetastatic activity in vitro.


Assuntos
Antineoplásicos/farmacologia , Antineoplásicos/farmacocinética , Genisteína/farmacologia , Genisteína/farmacocinética , Isoflavonas/farmacologia , Isoflavonas/farmacocinética , Neoplasias/tratamento farmacológico , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fosforilação , Glycine max/química , Tirosina/metabolismo
20.
World J Urol ; 21(1): 3-8, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12682772

RESUMO

Prostate cancer chemoprevention (CP) can be defined as the use of natural and synthetic agents that inhibit, reverse or regress precancer and delay progression to invasive cancer. During the past two decades several CP strategies have evolved. The first generation of CP trials tested the efficacy of antioxidants and vitamins including B-carotene, vitamin A, retinol, 13 cis retinoic acid, vitamins E, C and selenium. Although these trials were disappointing, provocative hypotheses were generated for selenium and vitamin E that set the stage for future prostate trials. In the 1990s, the NCI launched a second generation of large CP trials aimed at breast and prostate cancer. One of these trials is the PCPT, testing the efficacy of a 5 alpha-reductase inhibitor-finasteride to prevent prostate cancer in 18,000 men. Although PCPT is still in progress, the NCI recently launched a second large primary prostate CP trial called SELECT, testing the efficacy of selenium and vitamin E in 32,400 men. The Prostate Cancer Progress Report to the Director of NCI in 1998 challenged the research community to design more efficient CP trials for prostate cancer. In response, the NCI has evolved a third generation of CP trials. This involves pharmacologically driven translational science research including agents and their targets, biomarker endpoints, suitable clinical models for testing agents and efficient trial designs employing high risk cohorts and surrogate endpoints. In summary, a dual strategy for CP is being developed which includes public health measures and a medical intervention approach.


Assuntos
Neoplasias da Próstata/prevenção & controle , Antioxidantes/uso terapêutico , Ensaios Clínicos como Assunto , Humanos , Masculino , Micronutrientes/uso terapêutico , Vitaminas/uso terapêutico
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