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1.
J Phys Chem A ; 121(40): 7619-7626, 2017 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-28902519

RESUMO

We measured photolysis kinetics of the PAH anthracene in aqueous solution, in bulk ice, and at ice surfaces in the presence and absence of chromophoric dissolved organic matter (CDOM). Self-association, which occurs readily at ice surfaces, may be responsible for the faster anthracene photolysis observed there. Photolysis rate constants in liquid water increased under conditions where anthracene self-association was observed. Concomitantly, kinetics changed from first-order to second-order, indicating that the photolysis mechanism at ice surfaces might be different than that in aqueous solution. Other factors that could lead to faster photolysis at ice surfaces were also investigated. Increased photon fluxes due to scattering in the ice samples can account for at most 20% of the observed rate increase, and other factors including singlet oxygen (1O2*) production and changes in pH and polarity were determined not to be responsible for the faster photolysis. CDOM (in the form of fulvic acid (FA)) did not affect anthracene photolysis kinetics in aqueous solution but suppressed photolysis in ice cubes and ice granules (by 30% and 56%, respectively). This was primarily due to competitive photon absorption (the inner filter effect). Freeze-concentration (or "salting out") appears to slightly increase the suppressing effects of FA on anthracene photolysis. This may be due to increased competitive photon absorption or to physical interactions between anthracene and FA.

3.
Ann Oncol ; 27(12): 2196-2203, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27765757

RESUMO

BACKGROUND: We report the first randomized, Phase II trial of ramucirumab, an anti-vascular endothelial growth factor receptor-2 monoclonal antibody, as front-line therapy in patients with advanced adenocarcinoma of the esophagus or gastric/gastroesophageal junction (GEJ). PATIENTS AND METHODS: Patients from the USA with advanced esophageal, gastric, or GEJ adenocarcinoma randomly received (1:1) mFOLFOX6 plus ramucirumab (8 mg/kg) or mFOLFOX6 plus placebo every 2 weeks. The primary end point was progression-free survival (PFS) with 80% power to detect a hazard ratio (HR) of 0.71 (one-sided α = 0.15). Secondary end points included evaluation of response and overall survival (OS); an exploratory ramucirumab exposure-response analysis was undertaken. RESULTS: Of 168 randomized patients, 52% of tumors were located in the stomach/GEJ and 48% in the esophagus. The trial did not meet the primary end point of PFS [6.4 versus 6.7 months, HR 0.98 (95% confidence interval 0.69-1.37)] or the secondary end point of OS (11.7 versus 11.5 months) in the intent-to-treat (ITT) population. Objective response rates (45.2% versus 46.4%) were similar between arms. Most Grade ≥3 toxicities did not differ significantly between arms, yet premature discontinuation of FOLFOX and ramucirumab (for reasons other than progressive disease) was more common among ramucirumab- versus placebo-treated patients. In an exploratory analysis that censored for premature discontinuation, the HR for PFS favored the ramucirumab arm (HR 0.76), particularly in patients with gastric/GEJ cancer. An exploratory exposure-response analysis indicated that patients with higher ramucirumab exposure had longer OS. CONCLUSION: The addition of ramucirumab to front-line mFOLFOX6 did not improve PFS in the ITT population. CLINICALTRIALSGOV IDENTIFIER: NCT01246960.


Assuntos
Adenocarcinoma/tratamento farmacológico , Anticorpos Monoclonais/administração & dosagem , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Gástricas/tratamento farmacológico , Adenocarcinoma/patologia , Adulto , Idoso , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Intervalo Livre de Doença , Método Duplo-Cego , Neoplasias Esofágicas/patologia , Junção Esofagogástrica/efeitos dos fármacos , Feminino , Fluoruracila/administração & dosagem , Humanos , Estimativa de Kaplan-Meier , Leucovorina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Compostos Organoplatínicos/administração & dosagem , Resultado do Tratamento , Ramucirumab
5.
J Phys Chem A ; 118(9): 1638-43, 2014 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-24527955

RESUMO

We have investigated the effects of organic matter (OM) that does not absorb sunlight ("nonchromophoric") on the reactive environment presented by bulk ice and ice surfaces. Fluorescence spectroscopy showed that the presence of as little as 2.5 × 10(-4) M octanol or decanol reduces the extent to which naphthalene self-associates at ice surfaces, which indicates that naphthalene partitions between ice and organic phases present there. We also measured photolysis kinetics of the polycyclic aromatic hydrocarbons (PAHs) anthracene, pyrene, and phenanthrene in bulk ice and at ice surfaces containing 2.5 × 10(-5) M to 7.5 × 10(-3) M OM. In bulk ice, even the lowest concentrations of OM reduced photolysis kinetics to below our detection limits. Organic matter also reduced measured photolysis kinetics of PAHs at ice surfaces, but generally to a lesser extent than in bulk ice. Our results support previous reports that bulk ice and ice surfaces present distinct reaction environments, and show for the first time that OM can affect PAH photolysis kinetics by altering the physical environment within bulk ice and at ice surfaces.

6.
medRxiv ; 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38712176

RESUMO

Background: Recent data have demonstrated that in locally advanced rectal cancer (LARC), a total neoadjuvant therapy (TNT) approach improves compliance with chemotherapy and increases rates of tumor response compared to neoadjuvant chemoradiation (CRT) alone. They further indicate that the optimal sequencing of TNT involves consolidation (rather than induction) chemotherapy to optimize complete response rates. Data, largely from retrospective studies, have also shown that patients with clinical complete response (cCR) after neoadjuvant therapy may be managed safely with the watch and wait approach (WW) instead of preemptive total mesorectal resection (TME). However, the optimal consolidation chemotherapy regimen to achieve cCR has not been established, and a randomized clinical trial has not robustly evaluated cCR as a primary endpoint. Collaborating with a multidisciplinary oncology team and patient groups, we designed this NCI-sponsored study of chemotherapy intensification to address these issues and to drive up cCR rates, to provide opportunity for organ preservation, improve quality of life for patients and improve survival outcomes. Methods: In this NCI-sponsored multi-group randomized, seamless phase II/III trial (1:1), up to 760 patients with LARC, T4N0, any T with node positive disease (any T, N+) or T3N0 requiring abdominoperineal resection or coloanal anastomosis and distal margin within 12 cm of anal verge will be enrolled. Stratification factors include tumor stage (T4 vs T1-3), nodal stage (N+ vs N0) and distance from anal verge (0-4; 4-8; 8-12 cm). Patients will be randomized to receive neoadjuvant long course chemoradiation (LCRT) followed by consolidation doublet (mFOLFOX6 or CAPOX) or triplet chemotherapy (mFOLFIRINOX) for 3-4 months. LCRT in both arms involves 4500 cGy in 25 fractions over 5 weeks + 900 cGy boost in 5 fractions with a fluoropyrimidine (capecitabine preferred). Patients will undergo assessment 8-12 (+/- 4) weeks post-TNT completion. The primary endpoint for the phase II portion will compare cCR between treatment arms. A total number of 296 evaluable patients (148 per arm) will provide statistical power of 90.5% to detect an 17% increase in cCR rate, at a one-sided alpha=0.048. The primary endpoint for the phase III portion will compare disease-free survival (DFS) between treatment arms. A total of 285 DFS events will provide 85% power to detect an effect size of hazard ratio 0.70 at a one-sided alpha of 0.025, requiring enrollment of 760 patients (380 per arm). Secondary objectives include time-to event outcomes (overall survival, organ preservation time and time to distant metastasis) and adverse effects. Biospecimens including archival tumor tissue, plasma and buffy coat in EDTA tubes, and serial rectal MRIs will be collected for exploratory correlative research. This study, activated in late 2022, is open across the NCTN and has a current accrual of 312. Support: U10CA180821, U10CA180882, U24 CA196171; https://acknowledgments.alliancefound.org . Discussion: Building off of data from modern day rectal cancer trials and patient input from national advocacy groups, we have designed the current trial studying chemotherapy intensification via a consolidation chemotherapy approach with the intent to enhance cCR and DFS rates, increase organ preservation rates, and improve quality of life for patients with rectal cancer. Trial Registration: Clinicaltrials.gov ID: NCT05610163 ; Support includes U10CA180868 (NRG) and U10CA180888 (SWOG).

7.
Br J Cancer ; 107(8): 1354-60, 2012 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-22929886

RESUMO

BACKGROUND: A major challenge to the development of biomarkers for pancreatic cancer (PC) is the small amount of tissue obtained at the time of diagnosis. Single-gene analyses may not reliably predict biology of PC because of its complex molecular makeup. MicroRNA (miRNA) profiling may provide a more informative molecular interrogation of tumours. The primary objective of this study was to determine the feasibility of performing miRNA arrays and quantitative real-time PCR (qRT-PCR) from archival formalin-fixed paraffin-embedded (FFPE) cell blocks obtained from fine-needle aspirates (FNAs) that is the commonest diagnostic procedure for suspected PC. METHODS: MicroRNA expression profiling was performed on FFPE from FNA of suspicious pancreatic masses. Subjects included those who had a pathological diagnosis of pancreatic adenocarcinoma and others with a non-malignant pancreatic histology. Exiqon assay was used to quantify miRNA levels and qRT-PCR was used to validate abnormal expression of selected miRNAs. RESULTS: A total of 29 and 15 subjects had pancreatic adenocarcinoma and no evidence of cancer, respectively. The RNA yields per patient varied from 25 to 100 ng. Profiling demonstrated deregulation of over 228 miRNAs in pancreatic adenocarcinoma of which the top 7 were further validated by qRT-PCR. The expression of let-7c, let-7f, and miR-200c were significantly reduced in most patients whereas the expression of miR-486-5p and miR-451 were significantly elevated in all pancreas cancer patients. MicroRNAs let-7d and miR-423-5p was either downregulated or upregulated with a significant inter-individual variation in their expression. CONCLUSION: This study demonstrated the feasibility of using archival FFPE cell blocks from FNAs to establish RNA-based molecular signatures unique to pancreatic adenocarcinoma with potential applications in clinical trials for risk stratification, patient selection, and target validation.


Assuntos
Adenocarcinoma/genética , Neoplasias Pancreáticas/genética , Adenocarcinoma/patologia , Biópsia por Agulha , Estudos de Viabilidade , Perfilação da Expressão Gênica , Humanos , MicroRNAs , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias Pancreáticas/patologia
8.
Ann Oncol ; 21(10): 1999-2004, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20332133

RESUMO

BACKGROUND: Bevacizumab has demonstrated antitumor activity in multiple diseases. This phase II study was undertaken to determine the effects of adding bevacizumab to a regimen of docetaxel and oxaliplatin in patients with advanced adenocarcinoma of the stomach or gastroesophageal junction. PATIENTS AND METHODS: Previously untreated patients with locally advanced or metastatic disease and a performance status (PS) of 0-1 were eligible for this study. Patients received bevacizumab at 7.5 mg/kg, docetaxel at 70 mg/m(2), and oxaliplatin at 75 mg/m(2) administered on day 1 of a 21-day cycle. The primary end point of the study was progression-free survival (PFS). RESULTS: A total of 38 eligible patients (median age 57 years, 45% gastric, 55% PS 0) were enrolled on to the study. Median PFS was 6.6 months [95% confidence interval (CI) 4.4-10.5] and median survival 11.1 months (95% CI 8.2-15.3). Complete responses were documented in 2 (5%) patients, partial responses in 14 (37%), and stable disease in 14 (37%). No treatment-related deaths were observed. The most commonly reported grade 3-4 toxicity was neutropenia (34%), and gastrointestinal perforation occurred in three patients (8%). CONCLUSION: The combination of bevacizumab, docetaxel, and oxaliplatin has promising activity for further evaluation in randomized trials.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Junção Esofagogástrica/efeitos dos fármacos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Peritoneais/tratamento farmacológico , Neoplasias Gástricas/tratamento farmacológico , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/secundário , Adulto , Idoso , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais Humanizados , Bevacizumab , Neoplasias Ósseas/secundário , Docetaxel , Junção Esofagogástrica/patologia , Feminino , Humanos , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/secundário , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Compostos Organoplatínicos/administração & dosagem , Oxaliplatina , Neoplasias Peritoneais/secundário , Neoplasias Gástricas/patologia , Taxa de Sobrevida , Taxoides/administração & dosagem , Resultado do Tratamento
9.
Lung Cancer ; 52(3): 273-9, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16567020

RESUMO

Carcinoid tumors of the lung were first described in 1937, yet little is known about their etiology. The aim of the present investigation was to determine if there was excess risk of secondary cancers in a population-based sample after a lung carcinoid tumor diagnosis which may provide insight to the etiology. Subjects were 1882 cases diagnosed with carcinoid tumors of the lung between 1988 and 2000 whose information was obtained from the Surveillance, Epidemiology and End Results (SEER) Program database. Standardized incidence ratios were calculated by dividing the observed number of second primary cancers by the expected number of cancers. Excess risk of breast cancer was seen following diagnosis of a carcinoid tumor (SIR=1.80 95% CI 1.22-2.55). When stratified by time after diagnosis, excess risk of breast cancers in women was seen in the first 5 years after carcinoid diagnosis (SIR=1.68 95% CI 1.08-2.50) but fewer than expected breast cancers were diagnosed greater than 5 years after carcinoid diagnosis (SIR=0.29 95% CI 0.09-0.68). Prostate cancers also occurred 2.8 times more often than expected (95% CI 1.66-4.43), with risk being elevated only in the first 5 years post-carcinoid diagnosis. Development of lung carcinoids may be the result of genetic predisposition or environmental exposures, particularly those that are hormonally related. The role of genetics and sex hormones in lung carcinoid development, as well as the identification of other risk factors, should be explored.


Assuntos
Neoplasias da Mama/epidemiologia , Tumor Carcinoide/epidemiologia , Neoplasias Pulmonares/epidemiologia , Segunda Neoplasia Primária/epidemiologia , Neoplasias da Próstata/epidemiologia , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Neoplasias da Mama/história , Tumor Carcinoide/diagnóstico , Tumor Carcinoide/genética , Tumor Carcinoide/história , Feminino , História do Século XX , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/história , Masculino , Segunda Neoplasia Primária/diagnóstico , Segunda Neoplasia Primária/genética , Segunda Neoplasia Primária/história , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/genética , Neoplasias da Próstata/história , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo
10.
J Natl Cancer Inst ; 85(22): 1812-8, 1993 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-8230261

RESUMO

BACKGROUND: Many oncogenes have been shown to code for growth factor receptors that are involved in regulation of cell growth and proliferation and can activate transcription via protein kinase C. Bryostatin 1, a partial agonist of protein kinase C, has demonstrated potent antitumor activity in vitro and in vivo in human tumor xenografts. PURPOSE: The aim of this phase I study was to determine the optimal dosage and toxicity profile of bryostatin 1 and its influence on cytokine release in vivo. METHODS: Three successive cohorts consisting of 35 patients with various malignant tumors were treated with bryostatin 1 by intravenous infusion over 1 hour as follows: cohort A--35 micrograms/m2 (three patients) or 50 micrograms/m2 (eight patients) once every 2 weeks; cohort B--25 micrograms/m2 once a week (eight patients); and cohort C--25 micrograms/m2 once a week for 3 weeks, with no treatment during the 4th week (16 patients). Plasma levels of tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6) were measured by immunoradiometric assay and by radioimmunoassay, respectively. RESULTS: The dose-limiting toxicity was grade 3 or 4 myalgia in four of 11 patients in cohort A, in two of eight in cohort B, and in none of 16 in cohort C. Occurrence of myalgia was dose related. There was no significant myelosuppression, apart from a small and transient fall in platelet count. Six patients experienced acute but transient skin flushing, dyspnea, hypotension, and bradycardia, probably related to the bryostatin 1 vehicle. TNF-alpha and IL-6 were detected in plasma at 2 and 24 hours after treatment, respectively, and the levels were dose related (P = .02). Two patients with metastatic malignant melanoma had partial remission after three or four cycles of therapy; remission lasted 6 weeks and 10+ months, respectively. CONCLUSIONS: The dose-limiting toxicity of bryostatin 1 was myalgia. Plasma IL-6 and TNF-alpha concentrations were increased within 24 hours of therapy. Antitumor activity against malignant melanoma was observed early in the course of treatment. IMPLICATIONS: The recommended dosage of bryostatin 1 for phase II studies is 25 micrograms/m2 by intravenous infusion for 1 hour once a week for 3 weeks, with no treatment in the 4th week. IL-6 and TNF-alpha plasma concentrations may be useful in monitoring biological activity of bryostatin 1. Future studies should explore use of this drug with other conventional immune modulators and conventional cytotoxic drugs.


Assuntos
Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Interleucina-6/sangue , Lactonas/farmacologia , Lactonas/uso terapêutico , Fator de Necrose Tumoral alfa/metabolismo , Adulto , Idoso , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Briostatinas , Esquema de Medicação , Feminino , Humanos , Lactonas/administração & dosagem , Lactonas/efeitos adversos , Macrolídeos , Masculino , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Resultado do Tratamento
11.
Cancer Res ; 53(23): 5649-53, 1993 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-8242619

RESUMO

BW12C79 stabilizes the oxyhemoglobin molecule resulting in a reversible left-shift of the oxygen saturation curve. The activity of a number of bioreductive anticancer drugs, such as mitomycin C, may be enhanced under hypoxic conditions. Twenty-four patients with various malignancies received BW12C79 and mitomycin C. BW12C79 was administered i.v. with a loading dose (20-50 mg/kg) over 1 h followed by a maintenance infusion of 4 mg/kg/h for 5 h. Percentage modification of the oxyhemoglobin (degree of left-shift) was dose related with maximum modification of 56% and was maintained for the duration of maintenance infusion of BW12C79. Hemoglobin electrophoresis showed a fast moving band consistent with the BW12C79-oxyhemoglobin complex. Side effects at the top dose level comprised headache, nausea/vomiting, vein irritation, and myocardial ischemia. One other patient suffered from an acute encephalopathy of unknown etiology a few days following BW12C79. 31P magnetic resonance spectroscopy of exercising calf muscles showed increased breakdown of high energy phosphate stores and a greater reduction in pH. Recovery of the high energy phosphate stores after exercise was slow. These results were consistent with reduced oxygen supply due to either a left shift of the oxygen saturation curve and/or reduced muscle blood flow. BW12C79 did not interfere with the pharmacokinetics of mitomycin C. In conclusion, this phase I study demonstrates the feasibility of achieving a significant left shift in the oxygen saturation curve in cancer patients which is maintained for at least 5 h with acceptable toxicity. The maximum tolerated dose of BW12C79 was 50 mg/kg loading infusion followed by a maintenance infusion of 4 mg/kg/h. Magnetic resonance spectroscopy results were consistent with reduced supply of oxygen to exercising skeletal muscle. BW12C79 may be of potential benefit as an adjunct to bioreductive drugs in the treatment of solid tumors.


Assuntos
Benzaldeídos/administração & dosagem , Mitomicina/administração & dosagem , Músculos/metabolismo , Neoplasias/tratamento farmacológico , Oxigênio/metabolismo , Adulto , Idoso , Benzaldeídos/efeitos adversos , Quimioterapia Combinada , Feminino , Hemoglobinas/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Mitomicina/farmacocinética , Músculos/efeitos dos fármacos , Neoplasias/metabolismo
12.
J Clin Oncol ; 21(15): 2920-5, 2003 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-12885810

RESUMO

PURPOSE: This phase II study was undertaken to determine the efficacy of adding infusional fluorouracil (FU) to the chemotherapy doublet of gemcitabine and cisplatin in patients with advanced pancreatic cancer. PATIENTS AND METHODS: The eligibility criteria included histologically or cytologically confirmed adenocarcinoma of the pancreas that was either unresectable or metastatic. No prior gemcitabine therapy was allowed. Patients received a combination of gemcitabine 1000 mg/m2 intravenously (IV) on days 1, 8, and 15; cisplatin 50 mg/m2 IV on days 1 and 15; and FU 175 mg/m2/d from days 1 to 15 by continuous IV infusion. Cycles were repeated every 28 days. Objective tumor response and toxicity were evaluated according to the World Health Organization criteria. RESULTS: A total of 47 patients (median age, 57 years; males, 59%) were enrolled. Sixteen patients had locally advanced (LA) disease, and 31 patients had metastatic disease. A total of 183 cycles of chemotherapy were administered. In patients with metastatic disease (n = 31), the probability of survival at 6 and 12 months was 66% and 34%, respectively. Objective partial response or stable disease was observed in 26% (90% confidence interval [CI], 0.14 to 0.41) and 61% (90% CI, 0.45 to 0.74) of patients, respectively. In patients with LA disease (n = 16), there were three partial responses (19%; 90 CI, 0.07 to 0.39). One patient in this group was successfully resected after FU-based radiotherapy. The most common grade 3 to 4 toxicities were neutropenia (60%), thrombocytopenia (42%), and anemia (26%). Thirteen patients were hospitalized for treatment-related complications. CONCLUSION: The combination of gemcitabine, cisplatin, and infusional FU has significant activity in patients with advanced pancreatic cancer.


Assuntos
Adenocarcinoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Desoxicitidina/análogos & derivados , Neoplasias Pancreáticas/tratamento farmacológico , Adenocarcinoma/patologia , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Desoxicitidina/administração & dosagem , Desoxicitidina/efeitos adversos , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/patologia , Análise de Sobrevida , Resultado do Tratamento , Gencitabina
13.
Clin Cancer Res ; 2(2): 303-10, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9816173

RESUMO

Dacarbazine (DTIC) is a DNA-methylating drug used in the treatment of malignant melanoma. Among the DNA dducts induced by DTIC are N7-methylguanine (N7-meG) and O6-methylguanine (O6-meG). The latter adduct, in particular, may be important in the mutagenic as well as the cytotoxic activity of DTIC. Repair of O6-meG is carried out by the enzyme O6-alkylguanine-DNA-alkyltransferase (AGT) by a process which results in its autoinactivation. N7-meG is lost from DNA partly spontaneously and partly by enzymatic depurination followed by excision repair of the resulting apurinic site. The purpose of this study was to determine the in vivo kinetics of formation and repair of O6-meG and N7-meG and the changes in AGT in peripheral WBCs with repeated doses of DTIC, and to determine the effects on these processes of concomitant administration of hydroxyurea. In addition, we examined the induction of mutations at the HPRT gene locus. Thirty-four patients with malignant melanoma received 1.0 g/m2 DTIC i.v. every 3 weeks. Hydroxyurea was added to the second and subsequent doses of DTIC in 19 patients. The concentrations of O6-meG, N7-meG, and AGT in peripheral blood lymphocytes were determined up to 24 h after each of the first two doses of DTIC. Mutations at the HPRT gene locus were determined using the T-cell clonal assay. Peak O6-meG levels were detected 1 and 4 h after the first and second dose of DTIC, respectively. AGT concentrations declined to 56.7% (range, 40.3-76.9%) and 55.0% (range, 45.4-58.9%) of pretreatment levels 24 h after the first and second doses of DTIC, respectively, and were still approximately 25%below their initial levels just prior to administration of the second dose of DTIC. An increase in formation of O6-meG was observed at all time points after the second dose of DTIC (P = 0.0001), which was not affected by cotreatment with hydroxyurea (P > 0.5). There was a negative correlation between pretreatment AGT levels and the O6-meG concentration at 24 h after therapy (r = -0.554, P = 0.014). N7-meG levels peaked at 6 h after DTIC therapy and were not significantly influenced by the cycle number. Cotreatment with hydroxyurea tended to be associated with lower levels of N7-meG (P = 0.08). There was no correlation between either O6-meG or N7-meG levels and the grade of neutropenia. On the basis of a limited series of blood samples analyzed, there was no firm evidence that chemotherapy with DTIC resulted in induction of HPRT mutations in lymphocytes. In conclusion, repeated administrations of DTIC resulted in higher concentrations of O6-meG, probably due to reduction in cellular AGT. Hydroxyurea did not significantly influence the kinetics of O6-meG, and N7-meG adduct formation. There was no significant induction of HPRT gene mutations with DTIC. This study suggests that sequencing of DTIC doses should be evaluated using the time course of cellular AGT depletion and DNA adduct formation to achieve higher cytotoxic efficiency.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Adutos de DNA/metabolismo , Reparo do DNA , Dacarbazina/administração & dosagem , Hidroxiureia/administração & dosagem , Hipoxantina Fosforribosiltransferase/genética , Melanoma/tratamento farmacológico , Mutação , Dacarbazina/efeitos adversos , Feminino , Guanina/análogos & derivados , Guanina/metabolismo , Humanos , Leucócitos/metabolismo , Masculino , Melanoma/genética , Pessoa de Meia-Idade , O(6)-Metilguanina-DNA Metiltransferase/metabolismo
14.
Clin Cancer Res ; 7(1): 38-42, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11205915

RESUMO

Current chemotherapy for patients with advanced colorectal cancer is relatively ineffective and may be associated with significant toxicity. Bryostatin 1 (bryo 1) influences cell proliferation, intracellular metabolism and signaling, differentiation, and apoptosis in human cancer cell lines via modulation of protein kinase C (PKC) activity. This trial investigates the efficacy and toxicity of bryo 1 as a novel therapeutic agent for patients with advanced colorectal cancer who have had previous 5-fluorouracil therapy. The primary end point was tumor response to bryo 1. Toxicity was also assessed. Twenty-eight patients with advanced colorectal cancer were enrolled. The mean age was 59 years (range, 38-76), with 16 men and 12 women, and good minority representation (11 African-Americans). The first 10 patients initially received 25 microg/m2 of bryo 1 weekly as a 24-h infusion for 3 weeks of every 4-week cycle, with dose escalation to 35 microg/m2 starting with the second cycle. The remaining patients were started at 35 microg/m2 and escalated to 40 microg/m2, if toxicity was minimal. Twenty-five patients were evaluable for objective tumor response, and complete data on toxicity were collected on 26 patients. No partial or complete tumor responses were observed. All 25 patients had disease progression within four cycles. Myalgia was the most common toxicity. Myelosuppression was not seen. bryo 1 as a weekly 24-h continuous infusion lacks single-agent antitumor activity in advanced colorectal cancer. Toxicity differs from that of traditional chemotherapeutic drugs.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Lactonas/uso terapêutico , Adulto , Idoso , Antineoplásicos/efeitos adversos , Briostatinas , Neoplasias Colorretais/patologia , Feminino , Humanos , Infusões Intravenosas , Lactonas/efeitos adversos , Macrolídeos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Resultado do Tratamento
15.
Eur J Cancer ; 30A(7): 1027-9, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7946568

RESUMO

Dacarbazine (DTIC) exerts its major biochemical effect through the formation of methylated DNA adducts. Hydroxyurea (HU) is a ribonucleotide reductase inhibitor which blocks DNA excision-repair by the depletion of intracellular ribonucleotides. Combination of HU and DTIC was used to enhance the activity of DTIC by inhibiting DNA repair. 16 patients with metastatic malignant melanoma were treated with the combination. All patients had measurable disease and none had received prior systemic therapy. Hydroxyurea was given as a continuous intravenous (i.v.) infusion of 1 g/h (total 36 g) and DTIC 1 g/m2 i.v. over 1 h, 23 h from the start of hydroxyurea infusion. 4 patients achieved partial remission with an objective remission rate of 25% [95% confidence interval (CI) 7-52%]. Median duration of response was 3.5 months. 3 of the responding patients had predominant visceral metastases. Disease was stabilised in 5 patients with a median time to progression of 16 months. The predominant toxicity to this treatment was gastrointestinal, with 3 patients developing grade 3 nausea/vomiting. Only 1 patient developed grade 3 leucopenia complicated by septicaemia. It is concluded that the combination of hydroxyurea and DTIC is a well-tolerated regimen with activity against visceral metastases from malignant melanoma but the duration of response to this treatment is short.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Melanoma/tratamento farmacológico , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Ósseas/secundário , Dacarbazina/administração & dosagem , Dacarbazina/efeitos adversos , Feminino , Neoplasias Gastrointestinais/secundário , Humanos , Hidroxiureia/administração & dosagem , Hidroxiureia/efeitos adversos , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/secundário , Masculino , Melanoma/secundário , Pessoa de Meia-Idade , Sarcoma de Células Claras/secundário , Resultado do Tratamento
16.
Eur J Cancer ; 28A(8-9): 1362-4, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1515252

RESUMO

4-Hydroxyanisole is a depigmenting agent which has been shown to have activity against malignant melanoma when given intra-arterially in man. An intravenous dose escalation study has been carried out with the aim of obtaining maximum plasma concentrations in a 5 day schedule. 8 patients entered this study which was stopped because of drug toxicity after 3 patients had been treated at the third dose escalation of 15 g/m2. 2 patients had WHO grade 4 liver and one also grade 4 renal toxicity and another had grade 4 haemoglobin toxicity. Extrapolated plateau plasma levels between 112 and 860 mumol/l were obtained, which in vitro studies suggested would be cytotoxic. Hopefully, newer analogues will have a greater specificity for the melanin pathway with less toxicity.


Assuntos
Anisóis/uso terapêutico , Antineoplásicos/uso terapêutico , Melanoma/tratamento farmacológico , Pigmentação/efeitos dos fármacos , Neoplasias Cutâneas/tratamento farmacológico , Anisóis/farmacocinética , Antineoplásicos/farmacocinética , Esquema de Medicação , Avaliação de Medicamentos , Estudos de Avaliação como Assunto , Humanos , Infusões Intravenosas , Metástase Linfática , Melanoma/sangue , Neoplasias Cutâneas/sangue
17.
Semin Oncol ; 24(1 Suppl 4): S32-8, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9122732

RESUMO

Treatment of metastatic malignant melanoma with recombinant interleukin-2 (rIL-2) represents one of the earliest attempts at systemic immunomodulation as a therapy for cancer. Initial reports showed objective response rates with single-agent rIL-2 therapy in the range of 15% to 20% with some durable responses; however, the overall response rates were lower than originally anticipated. In addition, in contrast to animal models, it appears that coadministration of lymphokine-activated killer (LAK) cells, generated ex vivo with rIL-2, does not enhance the response rates achieved with single-agent rIL-2. Despite a multitude of studies with various rIL-2 regimens, with and without coadministration of LAK cells or tumor-infiltrating lymphocytes, the optimum dose and treatment schedule for rIL-2-based therapy in metastatic melanoma remains a topic of controversy. To date, there are also no clear immunologic parameters that can predict biologic response to rIL-2-based therapy.


Assuntos
Interleucina-2/uso terapêutico , Melanoma/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Ensaios Clínicos como Assunto , Humanos , Interleucina-2/administração & dosagem , Células Matadoras Ativadas por Linfocina/transplante , Metástase Neoplásica , Proteínas Recombinantes/uso terapêutico , Linfócitos T/transplante , Resultado do Tratamento
18.
Semin Oncol ; 24(6 Suppl 19): S19-86-S19-88, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9427274

RESUMO

We initiated a phase II study to determine the efficacy of carboplatin and paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) in patients with advanced esophageal or gastric cancer. Objective tumor responses, duration of response, time to disease progression, overall survival, and toxicity profile are the end points evaluated in this study. The study includes patients with locally advanced metastatic or recurrent esophageal or gastric cancer with no history of prior chemotherapy or radiation treatment. Patients are required to have a performance status of 0 to 2 and no organ failure. Staging diagnostics include computed tomography scans and endoscopic ultrasound when appropriate. Starting dose of paclitaxel is 200 mg/m2, and carboplatin is given to achieve an area under the concentration-time curve of 5.0. Dose escalation is attempted if nadir counts permit. Seventeen patients have registered so far. Of those, three are not evaluable for efficacy analysis: one has not been on study long enough to be assessed for response and the other two are not assessable for objective tumor response. Three patients with gastric cancer have achieved partial responses. Two of five patients with esophageal cancer responded (partial response) to this treatment. Dose escalation by one step was feasible in approximately half the patients. There were no episodes of neutropenic fever. Carboplatin and paclitaxel given on an outpatient basis is well tolerated and an interesting regimen for the treatment of patients with advanced gastric or esophageal cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carboplatina/administração & dosagem , Neoplasias Esofágicas/tratamento farmacológico , Paclitaxel/administração & dosagem , Neoplasias Gástricas/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/toxicidade , Carboplatina/toxicidade , Neoplasias Esofágicas/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Paclitaxel/toxicidade , Neoplasias Gástricas/mortalidade , Taxa de Sobrevida , Resultado do Tratamento
19.
Int J Radiat Oncol Biol Phys ; 29(2): 277-83, 1994 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-8195019

RESUMO

PURPOSE: To determine the immunohistochemical expression of xenobiotic-metabolising enzymes (XME) in normal livers, primary hepatocellular carcinomas (hepatomas) and secondary hepatic tumors from colonic primary tumors. METHODS AND MATERIALS: The expression of XME in primary (n = 16) and secondary (n = 21) hepatic tumors and patients with no malignancies (n = 20) were investigated using polyclonal antibodies raised against the following rat enzymes CYP1A1, CYP2B1, CYP2C6, CYP3A1, CYP4A1, cytochrome P-450 reductase, epoxide hydrolase and testosterone UDP-glucuronyl transferase. The rat cytochrome P-450 antibodies recognize various human isoenzymes within the same gene family. Immunohistochemistry was undertaken using the immunoperoxidase and alkaline phosphatase anti-alkaline phosphatase techniques. RESULTS: There was a reduction in the overall expression of all XME by tumor tissue compared to adjacent nonneoplastic liver cells (p = 0.008), more in livers with secondary tumors (p < 0.0001) and reduced expression of XME by hepatomas and secondary liver tumors compared to livers with no malignancy. A tendency for higher expression of all XME by nonneoplastic liver cells from patients with hepatomas relative to nonmalignant livers was observed, with significantly higher expression of CYP3A4/5 and testosterone UDP-GT enzymes (odds ratio 3.12; CI 1.59-6.10). CONCLUSION: The expression of XME by tumor tissue is reduced in primary and secondary hepatic malignancies. The expression of XME by nonneoplastic liver cells is higher in patients with hepatomas than patients with no hepatic malignancies. These alterations in XME activities may have important therapeutic implications in the response and toxicity to systemic anti-cancer therapy, due to altered pharmacokinetics. In addition, differential expression of these enzymes by normal and malignant cells may be important for the rational design of selective anti-tumor drugs.


Assuntos
Sistema Enzimático do Citocromo P-450/análise , Neoplasias Hepáticas/enzimologia , Xenobióticos/metabolismo , Adulto , Feminino , Humanos , Imuno-Histoquímica , Fígado/enzimologia , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade
20.
Int J Radiat Oncol Biol Phys ; 53(3): 675-9, 2002 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-12062611

RESUMO

PURPOSE: We report our clinical experience with 32 patients receiving concurrent irradiation and capecitabine. METHODS AND MATERIALS: Medical records of patients with gastrointestinal malignancies treated with radiation and capecitabine therapy were reviewed. RESULTS: The population consisted of 20 males and 12 females, with a median age of 67.5 years (45-84 years) and adequate hepatic and bone marrow function. Histology was adenocarcinoma in all patients, except two with esophageal squamous carcinoma. Twenty-one patients received the regimen as adjuvant therapy, three received preoperative therapy, and 8 patients received therapy for palliation. The median dose of capecitabine was 1600 mg/m(2)/day (1200-2500 mg/m(2)/day) orally for 5 days per week for the duration of radiation therapy. Thirty patients received a total dose ranging from 45 Gy to 64 Gy over 4-6 weeks. Two previously radiated patients received total doses of 29.9 Gy and 46 Gy. Grade 3/4 toxicities observed were neutropenia in 3 patients and diarrhea, thrombocytopenia, fatigue, and myocardial infarction in 1 patient each. No treatment-related mortality was observed. Twenty of 21 patients (95.2%) who received adjuvant therapy continue to be in complete remission. Four of 11 (36%) evaluable patients demonstrated a response. CONCLUSION: Concurrent capecitabine and radiation were very well tolerated and warrant further investigation in prospective trials.


Assuntos
Adenocarcinoma/terapia , Antimetabólitos Antineoplásicos/uso terapêutico , Carcinoma de Células Escamosas/terapia , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Neoplasias Esofágicas/terapia , Neoplasias Gastrointestinais/terapia , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/radioterapia , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/efeitos adversos , Capecitabina , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Terapia Combinada , Desoxicitidina/efeitos adversos , Esquema de Medicação , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/radioterapia , Feminino , Fluoruracila/análogos & derivados , Neoplasias Gastrointestinais/tratamento farmacológico , Neoplasias Gastrointestinais/radioterapia , Humanos , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Radioterapia Conformacional , Indução de Remissão , Estudos Retrospectivos , Análise de Sobrevida
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