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1.
J Environ Manage ; 342: 118273, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37269728

RESUMO

There is a clear need for the development of management strategies to control dominant, perennial weeds and restore semi-natural communities and an important part of this is to know how long control treatments take to be effective and how long they last after treatments stop. Here, we report the results from a 17-year long experiment where we compared the effects of five control treatments on dense Pteridium aquilinum (L. Kuhn) relative to an untreated experimental-control in Derbyshire, UK. The experiment was run in two phases. In Phase 1 (2005-2012) we controlled the P. aquilinum by cutting and bruising, both twice and thrice annually, and a herbicide treatment (asulam in year 1, followed by annual spot-re-treatment of all emergent fronds). In Phase 2 (2012-2021) all treatments were stopped, and the vegetation was allowed to develop naturally. Between 2005 and 2021 we monitored P. aquilinum performance annually and full plant species composition at intervals. Here, we concentrate on analysing the Phase 2 data where we used regression approaches to model individual species responses through time and unconstrained ordination to compare treatment effects on the entire species composition over both Phases. Remote sensing was also used to assess edge invasion in 2018. At the end of Phase 1, a good reduction of P. aquilinum and restoration of acid-grassland was achieved for the asulam and cutting treatments, but not for bruising. In Phase 2, P. aquilinum increased through time in all treated plots but the asulam and cutting ones maintained a much lower P. aquilinum performance for nine years on all measures assessed. There was a reduction in species richness and richness fluctuations, especially in graminoid species. However, multivariate analysis showed that the asulam and cutting treatments were stationed some distance from the untreated and bruising treatments with no apparent sign of reversions suggesting an Alternative Stable State had been created, at least over this nine-year period. P. aquilinum reinvasion was mainly from plot edges. The use of repeated P. aquilinum control treatments, either through an initial asulam spray with annual follow-up spot-spraying or cutting twice or thrice annually for eight years gave good P. aquilinum control and helped restore an acid-grassland community. Edge reinvasion was detected, and it is recommended that either whole-patch control be implemented or treatments should be continued around patch edges.


Assuntos
Herbicidas , Pteridium , Pradaria , Carbamatos
2.
Plant Biol (Stuttg) ; 17(6): 1196-202, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26186487

RESUMO

Standing dead biomass retention is considered one of the most relevant fuel structural traits to affect plant flammability. However, very little is known about the biological significance of this trait and its distribution between different functional groups. Our aim was to analyse how the proportion of dead biomass produced in Mediterranean species is related to the successional niche of species (early-, mid- and late-successional stages) and the regeneration strategy of species (seeders and resprouters). We evaluated biomass distribution by size classes and standing dead biomass retention in nine dominant species from the Mediterranean Basin in different development stages (5, 9, 14 and 26 years since the last fire). The results revealed significant differences in the standing dead biomass retention of species that presented a distinct successional niche or regeneration strategy. These differences were restricted to the oldest ages studied (>9 years). Tree and small tree resprouters, typical in late-successional stages, presented slight variations with age and a less marked trend to retain dead biomass, while seeder shrubs and dwarf shrubs, characteristic of early-successional stages, showed high dead biomass loads. Our results suggest that the species that tend to retain more dead branches are colonising species that may promote fire in early-successional stages.


Assuntos
Biomassa , Ecossistema , Incêndios , Caules de Planta , Plantas , Sementes , Ecologia , Região do Mediterrâneo , Folhas de Planta , Fenômenos Fisiológicos Vegetais , Especificidade da Espécie , Árvores/crescimento & desenvolvimento , Água
3.
Cancer ; 92(6): 1613-20, 2001 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-11745240

RESUMO

BACKGROUND: Approximately 5-10% of patients with rhabdomyosarcomas (RMS) are diagnosed during the first year of life, and their clinical characteristics have been well documented. However, because RMS rarely occurs during the neonatal period, little is known about neonatal RMS. METHODS: Four patients with neonatal RMS were treated at St. Jude Children's Research Hospital between 1962 and 1999. The authors report the results of a review of these patients and of cases described in the literature. Clinical, radiologic, and pathologic features of these patients and their outcomes were evaluated. RESULTS: One patient with embryonal RMS was treated successfully with a combination of systemic chemotherapy and local control measures. The other three patients had alveolar RMS. Two of them had multiple skin and subcutaneous metastatic nodules at the time of diagnosis and developed brain metastases early in their course. In one of these patients, the PAX3-FKHR fusion transcript was detected. Three other similar cases of neonatal alveolar RMS with metastases to the skin and brain have been reported in the literature. CONCLUSIONS: A distinct syndrome of neonatal RMS is described. This syndrome is characterized by alveolar histology, multiple skin and subcutaneous metastases, and fatal outcome as the result of early brain metastasis.


Assuntos
Neoplasias Encefálicas/secundário , Rabdomiossarcoma Alveolar/patologia , Neoplasias Cutâneas/secundário , Neoplasias de Tecidos Moles/patologia , Feminino , Humanos , Recém-Nascido , Masculino , Radiografia , Rabdomiossarcoma Alveolar/congênito , Rabdomiossarcoma Alveolar/diagnóstico por imagem , Neoplasias Cutâneas/patologia , Neoplasias de Tecidos Moles/congênito , Neoplasias de Tecidos Moles/diagnóstico por imagem
4.
Clin Infect Dis ; 32(1): 36-43, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11112678

RESUMO

Empiric oral antibiotic therapy for febrile neutropenic cancer patients has been suggested as a means to decrease hospitalization, but the safety of this approach has not been adequately studied in children. We compared continued iv antibiotic therapy with switching treatment to orally administered cefixime in a group of selected febrile neutropenic children for whom blood cultures were sterile after 48 h of incubation. Two hundred episodes of febrile neutropenia were studied (156 patients), and 100 episodes were randomized to receive each treatment. Failure to respond to therapy was defined by documented or suspected bacterial infection, recurrent fever, or discontinuation of assigned therapy for any reason before neutropenia resolved. Rates of treatment failure were similar in the oral cefixime group (28%) and in the iv antibiotic group (27%; P=1.0). Results support the safety of oral cefixime therapy for low-risk febrile neutropenic children, a therapeutic approach that would facilitate earlier outpatient management and decrease the costs of treatment.


Assuntos
Cefixima/uso terapêutico , Cefalosporinas/uso terapêutico , Febre/complicações , Neoplasias/complicações , Neutropenia/tratamento farmacológico , Administração Oral , Adolescente , Adulto , Antibacterianos/administração & dosagem , Cefixima/administração & dosagem , Cefixima/efeitos adversos , Cefalosporinas/administração & dosagem , Cefalosporinas/efeitos adversos , Criança , Pré-Escolar , Qualidade de Produtos para o Consumidor , Feminino , Humanos , Lactente , Injeções Intravenosas , Masculino , Neutropenia/complicações , Falha de Tratamento
5.
Med Pediatr Oncol ; 35(4): 385-402, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11025469

RESUMO

The camptothecin analogs topotecan and irinotecan have shown to be among the most effective anticancer agents and, as S-phase specific agents, their antitumor effect is maximized when they are administered in protracted schedules. The documented activity as single agents in many adult and pediatric malignancies has been followed by their use in combination with other anticancer agents. These studies have shown promising results, and have placed topotecan and irinotecan in the first line treatment for some malignancies. However, studies to better determine the optimal schedules and sequence of combinations are needed.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Camptotecina/análogos & derivados , Camptotecina/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Neoplasias/tratamento farmacológico , Inibidores da Topoisomerase I , Topotecan/uso terapêutico , Adulto , Animais , Criança , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Resistencia a Medicamentos Antineoplásicos , Humanos , Irinotecano , Camundongos
6.
Leukemia ; 14(10): 1736-42, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11021748

RESUMO

The purpose of this study was to assess the feasibility and efficacy of a treatment regimen for pediatric acute myelogenous leukemia (AML) that uses four rotating drug pairs and adjusts dosages of etoposide and cytarabine to target specific plasma concentrations. Thirty-one girls and 27 boys (median age, 9.7 years) with de novo AML were treated on the protocol. Six cycles of chemotherapy were planned. Cycles 1 to 4 comprised the drug combinations cytarabine plus etoposide, cytarabine plus daunomycin, etoposide plus amsacrine, and etoposide plus azacitidine, respectively. For cycles 5 and 6, the first two combinations were repeated. Dosages were adjusted to achieve plasma concentrations of 1.0 microM +/- 0.1 microM cytarabine and 30 microM +/- 0.3 microM etoposide. Forty-four patients (76%) entered complete remission. Of those, 24 have had relapses; 23 remain alive in first or subsequent remission. The 5-year event-free survival (EFS) estimate was 31.0% +/- 5.9%; the 5-year survival estimate was 41.4% +/- 6.3%. Six patients (10%) died of the toxic effects of therapy. Severe neutropenia occurred in all cycles. Long-term complications of therapy included hepatitis C, cardiac insufficiency, and hearing loss. Adjustment of cytarabine and etoposide dosage was feasible for achieving targeted plasma drug concentrations; however, the potential clinical efficacy of this approach was offset by substantial acute and long-term toxicity.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Criança , Pré-Escolar , Citarabina/administração & dosagem , Citarabina/farmacocinética , Relação Dose-Resposta a Droga , Etoposídeo/administração & dosagem , Etoposídeo/farmacocinética , Feminino , Humanos , Lactente , Masculino , Resultado do Tratamento
7.
J Pediatr Hematol Oncol ; 22(4): 321-9, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10959902

RESUMO

PURPOSE: Current treatment of the Ewing sarcoma family of tumors (ESFT) includes intensive multiagent chemotherapy with topoisomerase II inhibitors, alkylating agents, and granulocyte colony-stimulating factor (G-CSF). This treatment approach has been associated with myelodysplasia and acute myeloid leukemia. Because macrocytosis and thrombocytopenia are distinctive features of myelodysplasia, the authors evaluated a cohort of patients treated for ESFT to determine the degree and duration of macrocytosis and thrombocytopenia and their relation with the development of therapy-related hematologic malignancies. PATIENTS AND METHODS: The study group consisted of 73 patients with ESFT treated on two consecutive protocols (EW92 and EW87). Both chemotherapy regimens incorporated the same agents but differed in cumulative drug dose, dose per course, and the use of G-CSF. Platelet counts and the mean corpuscular volume (MCV) of erythrocytes were determined at diagnosis and during follow-up visits after completion of treatment. RESULTS: Patients in the EW92 group had significantly greater MCVs after treatment than did the less intensively treated EW87 group. These changes persisted throughout the 40-month observation period. Patients in the EW92 group also had lesser mean platelet counts after treatment than those in the EW87 group. MCV differences (from baseline) were inversely related to platelet counts. The cumulative incidence of treatment-related acute myeloid leukemia was 7.8%+/-4.7% at 4 years in the EW92 group and zero in the EW87 group. CONCLUSION: Patients treated for ESFT with intensive chemotherapy that includes large doses of alkylators, topoisomerase II inhibitors, and G-CSF characteristically have persistently elevated MCVs and decreased platelet counts after completion of therapy. These hematologic abnormalities may represent stem cell damage, predisposing patients to myelodysplasia and acute myeloid leukemia, but further study is needed to establish this relation.


Assuntos
Anemia Macrocítica/induzido quimicamente , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Ósseas/sangue , Leucemia Mieloide/induzido quimicamente , Segunda Neoplasia Primária/induzido quimicamente , Sarcoma de Ewing/sangue , Trombocitopenia/induzido quimicamente , Adolescente , Adulto , Anemia Macrocítica/sangue , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Índices de Eritrócitos/efeitos dos fármacos , Feminino , Seguimentos , Humanos , Lactente , Leucemia Mieloide/sangue , Masculino , Síndromes Mielodisplásicas/induzido quimicamente , Segunda Neoplasia Primária/sangue , Contagem de Plaquetas/efeitos dos fármacos , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Retrospectivos , Sarcoma de Ewing/tratamento farmacológico , Trombocitopenia/sangue
8.
Cancer ; 89(2): 463-6, 2000 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-10918180

RESUMO

BACKGROUND: Epstein-Barr virus (EBV) infection has been implicated in the pathogenesis of certain subtypes of salivary gland tumors in the adult population. However, to the authors' knowledge its role in pediatric salivary gland tumors, a rare disease, has not been explored previously. METHODS: Thirteen cases of primary tumors of the salivary gland occurring in children were retrieved from the tumor registry at the St. Jude Children's Research Hospital in Memphis, Tennessee. Clinical data were analyzed from the medical records and formalin fixed, paraffin embedded tumor tissues were examined by the in situ hybridization (ISH) technique for the presence of latent EBV infection. RESULTS: Twelve of 13 tumors originated from the parotid gland and 1 originated from the submandibular gland. Mucoepidermoid carcinoma was the predominant tumor type; it was observed in seven patients, rhabdomyosarcoma was the diagnosis in three patients, acinic cell carcinoma was noted in two patients, and malignant fibrous histiocytoma was diagnosed in one patient. The ages of the patients ranged from 4.1-29.2 years, with a median age of 11 years. The outcome was excellent with all patients alive and free of disease at the time of last follow-up. The ISH tested negative in all tumor samples. CONCLUSIONS: Based on the results of the current study, EBV infection does not appear to play a major role in the pathogenesis of pediatric salivary gland tumors.


Assuntos
Infecções por Vírus Epstein-Barr/complicações , Neoplasias Parotídeas/virologia , Neoplasias da Glândula Submandibular/virologia , Adolescente , Adulto , Carcinoma Mucoepidermoide/patologia , Carcinoma Mucoepidermoide/virologia , Criança , Pré-Escolar , Infecções por Vírus Epstein-Barr/genética , Feminino , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/fisiologia , Humanos , Hibridização In Situ , Masculino , Neoplasias Parotídeas/patologia , RNA Viral/análise , Neoplasias da Glândula Submandibular/patologia , Latência Viral
9.
J Clin Oncol ; 18(16): 3018-24, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10944136

RESUMO

PURPOSE: To determine the frequency of CNS involvement at diagnosis of non-Hodgkin's lymphoma (NHL), to characterize its pattern of presentation, and to determine its prognostic significance. PATIENTS AND METHODS: We reviewed the records of 445 children (1975 through 1995) diagnosed with NHL (small noncleaved cell NHL/B-cell acute lymphoblastic leukemia [SNCC NHL/B-ALL], 201 patients; lymphoblastic, 113; large cell, 119; other, 12). Tumor burden was estimated by serum lactate dehydrogenase (LDH) measurement and reclassification of disease stage irrespective of CNS involvement (modified stage). RESULTS: Thirty-six of 445 children with newly diagnosed NHL had CNS involvement (lymphoma cells in the CSF [n = 23], cranial nerve palsy [n = 9], both features [n = 4]), representing 13%, 7%, and 1% of small noncleaved cell lymphoma, lymphoblastic lymphoma, and large-cell cases, respectively. By univariate analysis, CNS disease at diagnosis did not significantly impact event-free survival (P =. 095), whereas stage and LDH did; however, children with CNS disease at diagnosis were at 2.0 times greater risk of death than those without CNS disease at diagnosis. In a multivariate analysis, CNS disease was not significantly associated with either overall or event-free survival, whereas both serum LDH and stage influenced both overall and event-free survival. Among cases of SNCC NHL/B-ALL, CNS disease was significantly associated with event-free and overall survival (univariate analysis); however, in multivariate analysis, only LDH had independent prognostic significance. Elevated serum LDH or higher modified stage were associated with a trend toward poorer overall survival among children with CNS disease. CONCLUSION: A greater tumor burden at diagnosis adversely influences the treatment outcome of children with NHL and CNS disease at diagnosis, suggesting a need for ongoing improvement in both systemic and CNS-directed therapy.


Assuntos
Doenças do Sistema Nervoso Central/etiologia , Doenças dos Nervos Cranianos/etiologia , Linfoma não Hodgkin/líquido cefalorraquidiano , Linfoma não Hodgkin/complicações , Adolescente , Antineoplásicos/administração & dosagem , Doenças do Sistema Nervoso Central/líquido cefalorraquidiano , Líquido Cefalorraquidiano/citologia , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Irradiação Craniana , Intervalo Livre de Doença , Feminino , Humanos , Lactente , Injeções Intralesionais , L-Lactato Desidrogenase/sangue , Linfoma Difuso de Grandes Células B/líquido cefalorraquidiano , Linfoma Difuso de Grandes Células B/complicações , Linfoma Difuso de Grandes Células B/terapia , Linfoma não Hodgkin/terapia , Masculino , Análise Multivariada , Razão de Chances , Leucemia-Linfoma Linfoblástico de Células Precursoras/líquido cefalorraquidiano , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Prognóstico , Recidiva , Estudos Retrospectivos , Resultado do Tratamento
10.
Clin Cancer Res ; 6(3): 813-9, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10741701

RESUMO

Irinotecan (IRN), a topoisomerase I interactive agent, has significant antitumor activity in early Phase I studies in children with recurrent solid tumors. However, the disposition of IRN and its metabolites, SN-38 and APC, in children has not been reported. Children with solid tumors refractory to conventional therapy received IRN by a 1-h i.v. infusion at either 20, 24, or 29 mg/m2 daily for 5 consecutive days for 2 weeks. Serial blood samples were collected after doses 1 and 10 of the first course. IRN, SN-38, and APC lactone concentrations were determined by an isocratic high-performance liquid chromatography assay. A linear four-compartment model was fit simultaneously to the IRN, SN-38, and APC plasma concentration versus time data. Systemic clearance rate for IRN was 58.7 +/- 18.8 liters/h/m2 (mean +/- SD). The mean +/- SD ng/ml x h single-day lactone SN-38 area under the concentration-time curve (AUC(0-->6) was 90.9 +/- 96.4, 103.7 +/- 62.4, and 95.3 +/- 63.9 at IRN doses of 20, 24, and 29 mg/m2, respectively. The relative extent of IRN conversion to SN-38 and metabolism to APC measured after dose 1 were 0.49 +/- 0.33 and 0.29 +/- 0.17 (mean +/- SD). No statistically significant intrapatient difference was noted for SN-38 area under the concentration-time curve. Large interpatient variability in IRN and metabolite disposition was observed. The relative extent of conversion and the SN-38 systemic exposure achieved with this protracted schedule of administration were much greater than reported in adults or children receiving larger intermittent doses.


Assuntos
Antineoplásicos Fitogênicos/farmacocinética , Camptotecina/análogos & derivados , Neoplasias/tratamento farmacológico , Adolescente , Adulto , Antineoplásicos Fitogênicos/efeitos adversos , Antineoplásicos Fitogênicos/uso terapêutico , Área Sob a Curva , Camptotecina/sangue , Camptotecina/farmacocinética , Camptotecina/uso terapêutico , Criança , Pré-Escolar , Diarreia/induzido quimicamente , Relação Dose-Resposta a Droga , Esquema de Medicação , Humanos , Irinotecano , Recidiva Local de Neoplasia , Neoplasias/patologia , Neoplasias Complexas Mistas/tratamento farmacológico , Neoplasias Complexas Mistas/patologia , Neoplasias de Tecido Conjuntivo e de Tecidos Moles/tratamento farmacológico , Neoplasias de Tecido Conjuntivo e de Tecidos Moles/patologia , Neoplasias Epiteliais e Glandulares/tratamento farmacológico , Neoplasias Epiteliais e Glandulares/patologia , Neutropenia/induzido quimicamente , Fatores de Tempo
11.
J Clin Oncol ; 17(6): 1815-24, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10561220

RESUMO

PURPOSE: In a preclinical model of neuroblastoma, administration of irinotecan daily 5 days per week for 2 consecutive weeks ([qd x 5] x 2) resulted in greater antitumor activity than did a single 5-day course with the same total dose. We evaluated this protracted schedule in children. PATIENTS AND METHODS: Twenty-three children with refractory solid tumors were enrolled onto a phase I study. Cohorts received irinotecan by 1-hour intravenous infusion at 20, 24, or 29 mg/m(2) (qd x 5) x 2 every 21 days. RESULTS: The 23 children (median age, 14.1 years; median prior regimens, two) received 84 courses. Predominant diagnoses were neuroblastoma (n = 5), osteosarcoma (n = 5), and rhabdomyosarcoma (n = 4). The dose-limiting toxicity was grade 3/4 diarrhea and/or abdominal cramps in six of 12 patients treated at 24 mg/m(2), despite aggressive use of loperamide. The maximum-tolerated dose (MTD) on this schedule was 20 mg/m(2)/d. Five patients had partial responses and 16 had disease stabilization. On day 1, the median systemic exposure to SN-38 (the active metabolite of irinotecan) at the MTD was 106 ng-h/mL (range, 41 to 421 ng-h/mL). CONCLUSION: This protracted schedule is well tolerated in children. The absence of significant myelosuppression and encouraging clinical responses suggest compellingly that irinotecan be further evaluated in children using the (qd x 5) x 2 schedule, beginning at a dose of 20 mg/m(2). These results imply that data obtained from xenograft models can be effectively integrated into the design of clinical trials.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Camptotecina/análogos & derivados , Neoplasias/tratamento farmacológico , Neuroblastoma/tratamento farmacológico , Ensaio de Cápsula Sub-Renal , Adolescente , Adulto , Animais , Antineoplásicos Fitogênicos/efeitos adversos , Antineoplásicos Fitogênicos/farmacocinética , Camptotecina/administração & dosagem , Camptotecina/efeitos adversos , Camptotecina/farmacocinética , Criança , Pré-Escolar , Estudos de Coortes , Relação Dose-Resposta a Droga , Esquema de Medicação , Avaliação de Medicamentos , Feminino , Humanos , Irinotecano , Masculino , Camundongos , Resultado do Tratamento
12.
J Clin Oncol ; 17(12): 3697-705, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10577841

RESUMO

PURPOSE: The rarity and heterogeneity of pediatric nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) has precluded meaningful analysis of prognostic factors associated with surgically resected disease. To define a population of patients at high risk of treatment failure who might benefit from adjuvant therapies, we evaluated the relationship between various clinicopathologic factors and clinical outcome of children and adolescents with resected NRSTS over a 27-year period at our institution. PATIENTS AND METHODS: We analyzed the records of 121 consecutive patients with NRSTS who underwent surgical resection between August 1969 and December 1996. Demographic data, tumor characteristics, treatment, and outcomes were recorded. Univariate and multivariate analyses of prognostic factors for survival, event-free survival (EFS), and local and distant recurrence were performed. RESULTS: At a median follow-up of 9.2 years, 5-year survival and EFS rates for the entire cohort were 89% +/- 3% and 77% +/- 4%, respectively. In univariate models, positive surgical margins (P =.004), tumor size > or = 5 cm (P <.001), invasivene (P =.002), high grade (P =.028), and intra-abdominal primary tumor site (P =.055) adversely affected EFS. All of these factors except invasiveness remained prognostic of EFS and survival in multivariate models. Positive surgical margins (P =.003), intra-abdominal primary tumor site (P =.028), and the omission of radiation therapy (P =.043) predicted local recurrence, whereas tumor size > or = 5 cm (P <.001), invasiveness (P <.001), and high grade (P =.004) predicted distant recurrence. CONCLUSION: In this largest single-institution analysis of pediatric patients with surgically resected NRSTS, we identified clinicopathologic features predictive of poor outcome. These variables should be prospectively evaluated as risk-adapted therapies are developed.


Assuntos
Sarcoma/diagnóstico , Adolescente , Adulto , Quimioterapia Adjuvante , Criança , Pré-Escolar , Intervalo Livre de Doença , Seguimentos , Humanos , Lactente , Recidiva Local de Neoplasia/epidemiologia , Avaliação de Resultados em Cuidados de Saúde , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Sarcoma/tratamento farmacológico , Sarcoma/mortalidade , Sarcoma/cirurgia , Resultado do Tratamento
13.
J Pediatr Surg ; 34(5): 672-5, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10359161

RESUMO

BACKGROUND/PURPOSE: Because the management of pediatric nonrhabdomyosarcoma soft tissue sarcomas (NRSTS) is determined by extrapolation from adult studies, the effect of margin of tumor resection and postoperative radiation therapy (RT) on local tumor recurrence in children has not been assessed. METHODS: Records of NRSTS patients from a single institution were reviewed with regard to demographic data, TNM staging, grade, histological type and site of primary tumor, RT, and local tumor recurrence. The margin of resection was determined by pathological review and did not necessarily reflect operative margins. RESULTS: Eighty-eight clinical group I patients were treated over a 30-year period. The most common histological tumor subtypes were synovial cell sarcoma (n = 26), malignant fibrous histiocytoma (n = 17), and fibrosarcoma (n = 7). The mean age was 9.4 years (range, 0 to 29 years). Thirty-four patients had high-grade tumors. Two of ten patients with low-grade tumors and margins less than 1 cm, including one of five who had received RT, had a local recurrence. Patients with low-grade tumors and margins greater than 1 cm (n = 44) had a lower recurrence rate (2 of 44, 4.5%). None of these patients had received RT. Fourteen patients with high-grade tumors had margins less than 1 cm. Seven of these had RT and had no recurrence. Three of the seven patients who received no RT had a recurrence (42.9%). None of the 20 patients with high-grade tumors and margins greater than 1 cm received RT; four of these patients had recurrences (20%). Seven of the 12 irradiated patients (58.3%) had serious radiation-associated complications (wound dehiscence, fracture, growth retardation, and joint dysfunction). CONCLUSIONS: Grade alone does not determine the rate of local recurrence. In both low- and high-grade tumors, a pathological margin of resection greater than 1 cm reduced local recurrence. Radiotherapy provided no advantage in low grade tumors but did decrease local recurrence rates in high-grade tumors with less than 1 cm pathological margins.


Assuntos
Sarcoma/cirurgia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Histiocitoma Fibroso Benigno/patologia , Histiocitoma Fibroso Benigno/radioterapia , Histiocitoma Fibroso Benigno/cirurgia , Humanos , Lactente , Masculino , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Sarcoma/patologia , Sarcoma/radioterapia , Sarcoma Sinovial/patologia , Sarcoma Sinovial/radioterapia , Sarcoma Sinovial/cirurgia , Resultado do Tratamento
14.
Cancer Chemother Pharmacol ; 43(6): 454-60, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10321504

RESUMO

PURPOSE: Evaluation of inter- and intrapatient variability of topotecan oral bioavailability and disposition was performed in children with malignant solid tumors. PATIENTS AND METHODS: Topotecan i.v. formulation was given orally on schedules of daily for 21 consecutive days (d x 21) or daily for 5 days per week for 3 weeks [(d x 5)3], in both cases repeated every 28 days. Topotecan doses of 0.8 and 1.1 mg/m2 per day were evaluated on both schedules. Serial plasma samples were obtained after oral and i.v. administration of topotecan at the beginning and end of the first course of therapy. Topotecan lactone and total concentrations were measured by a high-performance liquid chromatography (HPLC) assay, and a one-or two-compartment model was fit to the plasma concentration-time data after oral or i.v. administration, respectively. Topotecan oral bioavailability (F) was calculated as the ratio of the AUC determined after oral treatment (AUCpo) divided by the AUC calculated after i.v. administration. RESULTS: Pharmacokinetics studies were performed on 15 and 11 patients receiving 0.8 and 1.1 mg/m2 per day, respectively. After oral administration the topotecan lactone AUCpo and F determined for 0.8 and 1.1 mg/m2 per day were 13.6 +/- 5.8 and 25.1 +/- 12.9 ng ml(-1) h and 0.34 +/- 0.14 and 0.34 +/- 0.16, respectively. The within-patient variance for AUCpo and F was much smaller than the between-patient variance. The ratio of topotecan lactone to total concentration was consistently higher after oral as compared with i.v. administration. CONCLUSIONS: Large interpatient variability was noted in topotecan pharmacokinetics, whereas intrapatient variability was relatively small. Further studies of oral topotecan are warranted to evaluate the tolerance of shorter courses and to define further the interpatient variability.


Assuntos
Antineoplásicos/farmacocinética , Neoplasias/tratamento farmacológico , Topotecan/farmacocinética , Administração Oral , Adolescente , Adulto , Disponibilidade Biológica , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Injeções Intravenosas , Masculino , Recidiva Local de Neoplasia , Neoplasias/metabolismo , Topotecan/administração & dosagem
15.
Oncology (Williston Park) ; 12(8 Suppl 6): 84-93, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9726098

RESUMO

Clinical results with irinotecan (CPT-11 [Camptosar]) and other camptothecin derivatives in various cancers, although encouraging, have fallen short of the expectations predicted by preclinical models. One proposed explanation for this is that preclinical xenograft models do not predict for the sensitivity of human cancer. In this article, we describe the results of several studies suggesting that this explanation is incorrect. Instead, our results indicate that the discrepancy between clinical response rates and findings in preclinical models may be due to a failure to incorporate the principles learned from preclinical studies into the design of clinical trials. Our analysis suggests that if differences in host tolerance are taken into account, the xenograft models are quite accurate predictors of clinical response. Moreover, application of the principles derived from preclinical models to the design of clinical trials may significantly enhance clinical response rates. Thus, the camptothecin analogs provide a paradigm for better integrated, pharmacokinetically driven, preclinical and clinical development of new drugs.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Camptotecina/análogos & derivados , Ensaios Clínicos como Assunto , Animais , Neoplasias Encefálicas/tratamento farmacológico , Camptotecina/uso terapêutico , Criança , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Esquema de Medicação , Avaliação de Medicamentos , Feminino , Humanos , Irinotecano , Camundongos , Camundongos Endogâmicos CBA , Modelos Biológicos , Projetos de Pesquisa
16.
J Natl Cancer Inst ; 90(7): 505-11, 1998 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-9539245

RESUMO

BACKGROUND: Topotecan is a topoisomerase I inhibitor with activity against xenografts of childhood solid tumors and established clinical activity against neuroblastoma and rhabdomyosarcoma. We have studied the relationship between systemic exposure to and the antitumor activity of topotecan lactone (the active form of the drug) in the xenograft models. Furthermore, we determined whether the responses seen in these models occur at systemic exposure levels that are tolerable in children. METHODS: Neuroblastoma xenografts derived from the tumors of six different patients were established subcutaneously in immune-deprived mice. Topotecan was administered by intravenous bolus injection 5 days a week for 2 consecutive weeks, repeated every 21 days for three cycles. The minimum daily doses that induced complete responses (CRs) and partial responses (PRs) were determined. Topotecan lactone pharmacokinetic studies were performed in both tumor-bearing and nontumor-bearing mice. RESULTS: The minimum doses associated with CRs and PRs in four of the six neuroblastoma xenografts were 0.61 and 0.36 mg/kg body weight, respectively. The topotecan lactone single-day systemic exposures associated with these doses were 88 and 52 ng x hr/mL, respectively. There was an approximately sixfold difference in topotecan lactone systemic exposure (290 ng x hr/mL versus 52 ng x hr/mL) associated with achieving CRs in the least-sensitive and most-sensitive tumors, respectively. CONCLUSIONS: Neuroblastoma xenografts are highly sensitive to topotecan therapy, and responses in mice are achieved at systemic exposures similar to those that are clinically effective and tolerable in children. These results support the concept of deriving preclinical data relating systemic exposure to antitumor activity in xenograft models. Such data may be valuable in making informed decisions regarding the clinical development of new agents.


Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Neuroblastoma/tratamento farmacológico , Rabdomiossarcoma/tratamento farmacológico , Inibidores da Topoisomerase I , Topotecan/farmacologia , Neoplasias das Glândulas Suprarrenais/tratamento farmacológico , Animais , Antineoplásicos/farmacocinética , Neoplasias da Medula Óssea/tratamento farmacológico , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacocinética , Humanos , Camundongos , Camundongos Endogâmicos CBA , Espaço Retroperitoneal , Topotecan/farmacocinética , Transplante Heterólogo
17.
Med Pediatr Oncol ; 30(1): 22-7, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9371385

RESUMO

PURPOSE: To determine the frequency and types of dental abnormalities among children treated at a young age for cancer, as represented by neuroblastoma. PATIENTS AND METHODS: We retrospectively reviewed the dental records and panoramic radiographs of 542 children who were treated for neuroblastoma at our institution over a 31-year period. Patients in our study had to meet the following criteria: they were treated on an institutional protocol, they had undergone panoramic radiography, and their dental follow-up continued for at least 2 years after diagnosis. We evaluated the frequency of clinically or radiographically apparent microdontia, excessive caries, root stunting, hypodontia, and enamel hypoplasia in our study population. RESULTS: Of the 52 patients who met the study criteria, 71% developed dental abnormalities, comprising microdontia in 38%, excessive caries in 29%, root stunting in 17%, hypodontia in 17%, and enamel hypoplasia in 17%. In nearly half (23) of our patients, neuroblastoma was diagnosed on or before their first birthday. CONCLUSION: Children treated for neuroblastoma are at high risk for abnormal dental development. The abnormalities in these patients may require extensive dental care and can compromise their quality of life. Frequent dental examinations and an intense oral hygiene program before, during, and after treatment may improve overall dental health.


Assuntos
Antineoplásicos/efeitos adversos , Neuroblastoma/tratamento farmacológico , Doenças Dentárias/induzido quimicamente , Criança , Pré-Escolar , Humanos , Radiografia , Doenças Dentárias/diagnóstico por imagem , Doenças Dentárias/prevenção & controle
18.
Cancer ; 80(10): 1997-2004, 1997 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-9366304

RESUMO

BACKGROUND: Neuroblastoma is the most common extracranial solid tumor among pediatric patients, and orbital metastatic disease is not uncommon in these children. Physical signs as a consequence of orbital metastases, such as proptosis and periorbital ecchymosis, frequently are encountered. However, subsequent blindness is rare. METHODS: A retrospective study was conducted to determine the incidence, related physical findings, treatment, and outcome of children who developed visual loss during treatment for neuroblastoma. Medical records for a 24-year period (1971-1994) were reviewed to identify these patients. The charts, diagnostic imaging studies, and autopsy material of these patients were reviewed. RESULTS: Of the 450 patients treated for neuroblastoma at the study institution during this period, 47 presented with abnormalities in physical examination of the eye. Eight of these 47 patients and 7 others developed visual loss in at least 1 eye during the first week after diagnosis (n = 5), during primary therapy (n = 6), at recurrence (n 2), or after completion of therapy (n = 2). In ten patients the visual loss was a direct consequence of the primary disease process, whereas a direct relationship between loss of vision and neuroblastoma could not be identified in the remaining five patients. Proptosis and periorbital ecchymosis were the most common associated physical findings. Although ten patients received steroids and eight received radiation, visual loss could not be prevented or reversed in these patients. CONCLUSIONS: Early initiation of effective, multiagent chemotherapy remains the primary approach for the treatment of neuroblastoma and its ophthalmologic complications. Radiation therapy and steroids may have benefit but failed to show good effect in this series. The prevention and treatment of blindness is probably most relevant in infants and children age < 2 years because they have the best chance for cure.


Assuntos
Cegueira/etiologia , Neoplasias Oculares/complicações , Neuroblastoma/complicações , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Pré-Escolar , Neoplasias Oculares/patologia , Neoplasias Oculares/terapia , Feminino , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Neuroblastoma/patologia , Neuroblastoma/terapia , Estudos Retrospectivos , Resultado do Tratamento
19.
Leukemia ; 11(6): 792-6, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9177429

RESUMO

The purpose of this study was to define the therapy-associated dental abnormalities in survivors of acute lymphoblastic leukemia (ALL). We reviewed the clinical records and panoramic radiographs of 423 survivors of ALL who were treated on one of four consecutive protocols (1975-1991). Dental abnormalities included root stunting, microdontia, hypodontia, taurodontia (enlarged pulp chambers), and over-retention of primary teeth. The frequency of these factors was determined in relation to age at initiation of treatment (< or = 8 years vs > 8 years), addition of cranial irradiation, and chemotherapeutic protocol. A total of 423 patients met the study criteria. The abnormalities comprised root stunting in 24.4% (n = 103), microdontia in 18.9% (n = 80), hypodontia in 8.5% (n = 36), taurodontia in 5.9% (n = 25), and over-retention of primary dentition in 4.0% (n = 17). Patients who were < or = 8 years old at diagnosis or who received cranial irradiation therapy developed more dental abnormalities than did those > 8 years and those who did not receive cranial irradiation (42 vs 32%). Survivors of childhood ALL often have dental abnormalities that may affect their quality of life. Dental evaluation at diagnosis and frequent follow-up may help to ensure appropriate preventive measures and minimize dental and periodontal disease.


Assuntos
Antineoplásicos/efeitos adversos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/radioterapia , Radioterapia/efeitos adversos , Anormalidades Dentárias/etiologia , Fatores Etários , Criança , Pré-Escolar , Seguimentos , Humanos , Lesões por Radiação , Estudos Retrospectivos , Sobreviventes , Anormalidades Dentárias/induzido quimicamente
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