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1.
Oral Oncol ; 69: 38-45, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28559019

RESUMO

OBJECTIVE: Src family kinase (SFK) activation circumvents epidermal growth factor receptor (EGFR) targeting in head and neck squamous cell carcinoma (HNSCC); dual SFK-EGFR targeting could overcome cetuximab resistance. PATIENTS AND METHODS: We conducted a Simon two-stage, phase II trial of the SFK inhibitor, dasatinib, and cetuximab in biomarker-unselected patients with cetuximab-resistant, recurrent/metastatic HNSCC. Pre- and post-treatment serum levels of interleukin-6 (IL6) were measured by ELISA. HNSCC cell lines were assessed for viability and effects of IL6 modulation following dasatinib-cetuximab treatment. RESULTS: In the first stage, 13 patients were evaluable for response: 7 had progressive and 6 had stable disease (SD). Enrollment was halted for futility, and biomarker analysis initiated. Low serum IL6 levels were associated with SD (raw p=0.028, adjusted p=0.14) and improved overall survival (p=0.010). The IL6 classifier was validated in a separate trial of the same combination, but was unable to segregate survival risk in a clinical trial of cetuximab and bevacizumab suggesting serum IL6 may be specific for the dasatinib-cetuximab combination. Enhanced in vitro HNSCC cell death was observed with dasatinib-cetuximab versus single agent treatment; addition of IL6-containing media abrogated this effect. CONCLUSION: Clinical benefit and overall survival from the dasatinib-cetuximab combination were improved among patients with low serum IL6. Preclinical studies support IL6 as a modifier of dasatinib-cetuximab response. In the setting of clinical cetuximab resistance, serum IL6 is a candidate predictive marker specific for combined dasatinib-cetuximab. The trial was modified and redesigned as a biomarker-enriched Phase II study enrolling patients with undetectable IL6.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Cetuximab/administração & dosagem , Dasatinibe/administração & dosagem , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Interleucina-6/sangue , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma de Células Escamosas/sangue , Resistencia a Medicamentos Antineoplásicos , Feminino , Neoplasias de Cabeça e Pescoço/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Carcinoma de Células Escamosas de Cabeça e Pescoço , Análise de Sobrevida
2.
Ann Oncol ; 27(12): 2257-2262, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27733374

RESUMO

BACKGROUND: Treatment intensification for resected, high-risk, head and neck squamous cell carcinoma (HNSCC) is an area of active investigation with novel adjuvant regimens under study. In this trial, the epidermal growth-factor receptor (EGFR) pathway was targeted using the IgG2 monoclonal antibody panitumumab in combination with cisplatin chemoradiotherapy (CRT) in high-risk, resected HNSCC. PATIENTS AND METHODS: Eligible patients included resected pathologic stage III or IVA squamous cell carcinoma of the oral cavity, larynx, hypopharynx, or human-papillomavirus (HPV)-negative oropharynx, without gross residual tumor, featuring high-risk factors (margins <1 mm, extracapsular extension, perineural or angiolymphatic invasion, or ≥2 positive lymph nodes). Postoperative treatment consisted of standard RT (60-66 Gy over 6-7 weeks) concurrent with weekly cisplatin 30 mg/m2 and weekly panitumumab 2.5 mg/kg. The primary endpoint was progression-free survival (PFS). RESULTS: Forty-six patients were accrued; 44 were evaluable and were analyzed. The median follow-up for patients without recurrence was 49 months (range 12-90 months). The probability of 2-year PFS was 70% (95% CI = 58%-85%), and the probability of 2-year OS was 72% (95% CI = 60%-87%). Fourteen patients developed recurrent disease, and 13 (30%) of them died. An additional five patients died from causes other than HNSCC. Severe (grade 3 or higher) toxicities occurred in 14 patients (32%). CONCLUSIONS: Intensification of adjuvant treatment adding panitumumab to cisplatin CRT is tolerable and demonstrates improved clinical outcome for high-risk, resected, HPV-negative HNSCC patients. Further targeted monoclonal antibody combinations are warranted. REGISTERED CLINICAL TRIAL NUMBER: NCT00798655.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Cisplatino/administração & dosagem , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/radioterapia , Adulto , Idoso , Anticorpos Monoclonais/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma de Células Escamosas/patologia , Cisplatino/efeitos adversos , Terapia Combinada , Intervalo Livre de Doença , Receptores ErbB/antagonistas & inibidores , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/radioterapia , Estadiamento de Neoplasias , Panitumumabe , Carcinoma de Células Escamosas de Cabeça e Pescoço
3.
Ann Oncol ; 27(8): 1594-600, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27177865

RESUMO

BACKGROUND: We previously reported the safety of concurrent cetuximab, an antibody against epidermal growth factor receptor (EGFR), pemetrexed, and radiation therapy (RT) in patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN). In this non-comparative phase II randomized trial, we evaluated this non-platinum combination with or without bevacizumab, an inhibitor of vascular endothelial growth factor (VEGF). PATIENTS AND METHODS: Patients with previously untreated stage III-IVB SCCHN were randomized to receive: conventionally fractionated radiation (70 Gy), concurrent cetuximab, and concurrent pemetrexed (arm A); or the identical regimen plus concurrent bevacizumab followed by bevacizumab maintenance for 24 weeks (arm B). The primary end point was 2-year progression-free survival (PFS), with each arm compared with historical control. Exploratory analyses included the relationship of established prognostic factors to PFS and quality of life (QoL). RESULTS: Seventy-eight patients were randomized: 66 oropharynx (42 HPV-positive, 15 HPV-negative, 9 unknown) and 12 larynx; 38 (49%) had heavy tobacco exposure. Two-year PFS was 79% [90% confidence interval (CI) 0.69-0.92; P < 0.0001] for arm A and 75% (90% CI 0.64-0.88; P < 0.0001) for arm B, both higher than historical control. No differences in PFS were observed for stage, tobacco history, HPV status, or type of center (community versus academic). A significantly increased rate of hemorrhage occurred in arm B. SCCHN-specific QoL declined acutely, with marked improvement but residual symptom burden 1 year post-treatment. CONCLUSIONS: RT with a concurrent non-platinum regimen of cetuximab and pemetrexed is feasible in academic and community settings, demonstrating expected toxicities and promising efficacy. Adding bevacizumab increased toxicity without apparent improvement in efficacy, countering the hypothesis that dual EGFR-VEGF targeting would overcome radiation resistance, and enhance clinical benefit. Further development of cetuximab, pemetrexed, and RT will require additional prospective study in defined, high-risk populations where treatment intensification is justified.


Assuntos
Carcinoma de Células Escamosas/tratamento farmacológico , Cetuximab/administração & dosagem , Receptores ErbB/genética , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Pemetrexede/administração & dosagem , Fator A de Crescimento do Endotélio Vascular/genética , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/efeitos adversos , Bevacizumab/administração & dosagem , Bevacizumab/efeitos adversos , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/radioterapia , Cetuximab/efeitos adversos , Intervalo Livre de Doença , Receptores ErbB/antagonistas & inibidores , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Masculino , Terapia de Alvo Molecular , Estadiamento de Neoplasias , Pemetrexede/efeitos adversos , Qualidade de Vida , Carcinoma de Células Escamosas de Cabeça e Pescoço , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores
4.
Oncogene ; 29(37): 5135-45, 2010 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-20622897

RESUMO

Epidermal growth factor receptor (EGFR) is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC) where aberrant signaling downstream of this receptor contributes to tumor growth. EGFR variant III (EGFRvIII) is the most commonly altered form of EGFR and contains a truncated ligand-binding domain. We previously reported that EGFRvIII is expressed in up to 40% of HNSCC tumors where it is associated with increased proliferation, tumor growth and chemoresistance to antitumor drugs including the EGFR-targeting monoclonal antibody cetuximab. Cetuximab was FDA-approved in 2006 for HNSCC but has not been shown to prevent invasion or metastasis. This study was undertaken to evaluate the mechanisms of EGFRvIII-mediated cell motility and invasion in HNSCC. We found that EGFRvIII induced HNSCC cell migration and invasion in conjunction with increased signal transducer and activator of transcription 3 (STAT3) activation, which was not abrogated by cetuximab treatment. Further investigation showed that EGF-induced expression of the STAT3 target gene HIF1-α, was abolished by cetuximab in HNSCC cells expressing wild-type EGFR under hypoxic conditions, but not in EGFRvIII-expressing HNSCC cells. These results suggest that EGFRvIII mediates HNSCC cell migration and invasion by increased STAT3 activation and induction of HIF1-α, which contribute to cetuximab resistance in EGFRvIII-expressing HNSCC tumors.


Assuntos
Carcinoma de Células Escamosas/patologia , Receptores ErbB/fisiologia , Neoplasias de Cabeça e Pescoço/patologia , Invasividade Neoplásica , Fator de Transcrição STAT3/metabolismo , Carcinoma de Células Escamosas/genética , Receptores ErbB/genética , Neoplasias de Cabeça e Pescoço/genética , Humanos
5.
J Immunol Methods ; 325(1-2): 51-66, 2007 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-17617419

RESUMO

Natural killer (NK) cell-or T cell-mediated cytotoxicity traditionally is measured in 4-16 h (51)Cr-release assays (CRA). A new four-color flow cytometry-based cytotoxicity assay (FCC) was developed to simultaneously measure NK cell cytotoxicity and NK cell phenotype (CD3(-)CD16(+)CD56(+)). Target cells, K562 or Daudi, were labeled with Cell Tracker Orange (CTO) prior to the addition of effector cells. Following co-incubation, 7 amino-actinomycin D (7-AAD) was added to measure death of target cells. The phenotype of effectors, viability of targets, the formation of tumor-effector cell conjugates and absolute numbers of all cells were measured based on light scatter (FSC/SSC), double discrimination of the fluorescence peak integral and height, and fluorescence intensity. Kinetic studies (0.5 and 1 to 4 h) at different effector to target (E:T) cell ratios (50, 25, 12, and 6) confirmed that the 3 h incubation was optimal. The FCC assay is more sensitive than the CRA, has a coefficient of variation (CV) 8-13% and reliably measures NK cell-or lymphokine-activated killer (LAK) cell-mediated killing of target cells in normal controls and subjects with cancer. The FCC assay can be used to study a range of phenotypic attributes, in addition to lytic activity of various subsets of effector cells, without radioactive tracers and thus, it is relatively inexpensive. The FCC assay has a potential for providing information about molecular interactions underlying target cell lysis and thus becoming a major tool for studies of disease pathogenesis as well as development of novel immune therapies.


Assuntos
Testes Imunológicos de Citotoxicidade/métodos , Citometria de Fluxo/métodos , Imunofenotipagem/métodos , Células Matadoras Ativadas por Linfocina/imunologia , Células Matadoras Naturais/imunologia , Antígenos CD/análise , Antígenos de Diferenciação de Linfócitos T/análise , Complexo CD3/análise , Antígeno CD56/análise , Linhagem Celular Tumoral , Radioisótopos de Cromo/metabolismo , Dactinomicina/análogos & derivados , Dactinomicina/química , Corantes Fluorescentes/química , Proteínas Ligadas por GPI , Granzimas/análise , Humanos , Células K562 , Células Matadoras Ativadas por Linfocina/química , Células Matadoras Ativadas por Linfocina/metabolismo , Células Matadoras Naturais/química , Células Matadoras Naturais/metabolismo , Cinética , Lectinas Tipo C , Leucócitos Mononucleares/imunologia , Neoplasias/imunologia , Neoplasias/metabolismo , Neoplasias/patologia , Receptores de IgG/análise , Reprodutibilidade dos Testes , Subpopulações de Linfócitos T/química , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Citotóxicos/química , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Fatores de Tempo
6.
Ann Oncol ; 16(5): 780-5, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15728108

RESUMO

BACKGROUND: Gefitinib (Iressa) is active as a single agent in the treatment of select patients with recurrent non-small cell lung cancer (NSCLC). The clinical characteristics of patients treated with gefitinib on an Expanded Access Program (EAP) at our institution identified predictive variables associated with better outcome. PATIENTS AND METHODS: Patients (n=199) with advanced NSCLC were treated with gefitinib (250 mg) upon progression with chemotherapy. Baseline patient characteristics were: median age, 69 years; males, 57%; adenocarcinoma, 56%. RESULTS: Partial responses were noted in two patients (1%) and disease stabilization in 66 (35%) patients. The median survival (MS) was 5.9 months [95% confidence interval (CI) 4.1-7.1] and median time to progression was 3 months (95% CI 2.0-3.0). The predictive factors analyzed were gender, skin rash, diarrhea, tumor histology and performance status (PS). Patients who developed skin rash (any grade) had MS of 10.8 months versus 4.0 months for those without rash (P <0.0001, log rank test). Patients with PS 0, 1 and 2 had MS of 8.4, 6.2 and 2.8 months, respectively (P <0.0002). The other factors did not impact survival. CONCLUSIONS: Occurrence of skin rash and baseline PS of 0/1 were associated with improved survival with gefitinib for recurrent NSCLC patients at our institution.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/mortalidade , Quinazolinas/uso terapêutico , Terapia de Salvação , Adulto , Idoso , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Quimioterapia Adjuvante , Intervalos de Confiança , Relação Dose-Resposta a Droga , Esquema de Medicação , Exantema/induzido quimicamente , Exantema/epidemiologia , Feminino , Gefitinibe , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Pneumonectomia/métodos , Valor Preditivo dos Testes , Probabilidade , Prognóstico , Estudos Prospectivos , Quinazolinas/efeitos adversos , Medição de Risco , Estatísticas não Paramétricas , Análise de Sobrevida , Resultado do Tratamento
7.
Adv Otorhinolaryngol ; 62: 161-72, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15608426

RESUMO

Apoptosis of circulating CD8+T cells seen in patients with squamous cell carcinoma of the head and neck (HNSCC) suggests a possibility of lymphocyte imbalance. Therefore, absolute numbers and percentages of T lymphocyte subsets were examined in the peripheral blood of patients with HNSCC and age-matched controls. Venous blood was obtained from 148 patients with HNSCC and 54 normal volunteers. Absolute numbers of CD3+, CD4+ and CD8+ T lymphocytes were determined using fluorobeads in a flow-cytometry-based technique. Percentages of T lymphocyte subsets were also evaluated by flow cytometry. The patients were grouped, at the time of blood draw (active vs. no evident disease, NED), type of therapy administered and the length of follow-up. Patients with HNSCC were found to have significantly lower absolute numbers of CD3+, CD4+and CD8+T cells than normal controls (NC). However, no differences in the percentages of T cell subsets between patients and NC were observed. Patients with active disease had significantly lower CD3+ and CD4+ T cell counts than those with NED. Patients with NED after surgery and radiotherapy had lower T cell counts than those treated by surgery alone. Patients who remained without evident disease for more than 2 years did not recover their T cell counts, and the T cell imbalance was evident many years after curative surgery. Patients with recurrent disease at the time of blood draw tended to have the lowest CD4+T cell counts. The TNM stage or site of the disease were not related to the absolute T cell count. Our data indicate that patients with HNSCC have altered lymphocyte homeostasis, which persists for months or years after curative therapies.


Assuntos
Apoptose/fisiologia , Contagem de Linfócito CD4 , Carcinoma de Células Escamosas/sangue , Neoplasias de Cabeça e Pescoço/sangue , Subpopulações de Linfócitos T/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Relação CD4-CD8 , Carcinoma de Células Escamosas/fisiopatologia , Estudos de Casos e Controles , Feminino , Neoplasias de Cabeça e Pescoço/fisiopatologia , Humanos , Ativação Linfocitária , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Sensibilidade e Especificidade , Estatísticas não Paramétricas
8.
Lung Cancer ; 43(3): 335-44, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15165093

RESUMO

PURPOSE: To define the maximum tolerated dose (MTD) and the nature of the toxicities associated with gemcitabine given as a short infusion to patients with non-small cell lung cancer (NSCLC). Secondary objectives were to monitor immunologic response, clinical response, and survival. PATIENTS AND METHODS: Thirty-two patients diagnosed with advanced inoperable NSCLC and performance status of 0 or 1 participated in this study. Patients consisted of 22 males and 10 females whose median age was 62 years (range 32-79). Gemcitabine was administered as a 30 min infusion once weekly for 3 weeks followed by 1 week of rest. Patients were enrolled at six gemcitabine dose levels ranging from 1000 to 3500 mg/m2. Patients completed a median of four cycles (range 1-17). Responses were evaluated after every two cycles. RESULTS: Toxicity was evaluated in all 32 patients. The MTD was not reached as gemcitabine was well tolerated at all dose levels. Grade 4 toxicity occurred in three (9%) patients: pulmonary and lymphocytopenia in one patient each, and both neurocortical and cardiac in one patient. Grade 3 toxicity was found in a total of 20 (63%) patients: pulmonary in 10 (31%) patients; pain in 6 (19%) patients; liver toxicity in 6 (19%) patients; leukopenia and lymphocytopenia in 5 (16%) patients each; anemia, nausea, and cardiac toxicity in 3 (9%) patients each; proteinuria and infection in 2 (6%) patients each; and hemorrhage in 1 (3%) patient. Of the 29 patients evaluable for response, seven objective responses were achieved: six at the 2200 mg/m2 dose level and one at the 2800 mg/m2 dose level. The distribution of responses differed significantly by dose (P = 0.0124 by the exact chi-square test for independence). The overall response rate was 24.1% (95% CI, 10.3-43.5%). At 6 h post-infusion, there was a significant increase in spontaneous tumor necrosis factor (TNF) release and stimulated interleukin (IL)-2 production, and significant decreases in total white blood cell and lymphocyte counts (CD3+, CD8+, and CD16+ lymphocytes) and resting and stimulated superoxide production by formyl-methionyl-leucyl-phenylalanine (fMLP), phorbol myristate acetate, and opsonized zymosan (OPS-Z). At 24 h post-infusion, there were significant decreases in total lymphocyte count, lymphocyte subsets (CD3+, CD4-, CD8+, CD56+, CD19+), and in resting and stimulated superoxide production by fMLP and OPS-Z. There also appeared to be an association between the levels of spontaneous TNF release and the severity of both gastrointestinal (GI) and pulmonary toxicities. CONCLUSION: Gemcitabine given as a short infusion was well tolerated at the dose levels of 1000-3500 mg/m2. The MTD was not reached. Toxicities appeared to be cumulative with multiple cycles. Gemcitabine appears to have activity against NSCLC. Although there was a differential dose-response rate among dose levels, increasing the gemcitabine dose beyond 2200mg/m2 did not show increased clinical response. Gemcitabine appears to modulate the immune response, which may in turn mediate both response and toxicity, although no statistically significant correlation between immune and clinical response was detected.


Assuntos
Antimetabólitos Antineoplásicos/administração & dosagem , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Citocinas/metabolismo , Desoxicitidina/análogos & derivados , Desoxicitidina/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Superóxidos/metabolismo , Adenocarcinoma/tratamento farmacológico , Adulto , Idoso , Carcinoma de Células Escamosas/tratamento farmacológico , Feminino , Granulócitos/metabolismo , Humanos , Infusões Intravenosas , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Gencitabina
9.
Gynecol Oncol ; 90(1): 3-9, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12821334

RESUMO

OBJECTIVE: After the completion of primary chemotherapy, the majority of advanced ovarian cancer patients have persistent, chemoresistant disease. Comparative genomic hybridization (CGH) has been used to study genetic alterations that may be responsible for chemoresistance in ovarian cancer. CGH is a useful, genomewide screen but resolution is limited to 5-10 Mb. Recently, quantitative microsatellite analysis (QuMA), a TaqMan-based quantitative PCR technology, has been used for higher resolution of DNA copy number abnormalities. Our goal is to identify specific chromosomal aberrations correlated with platinum resistance. METHODS: Snap-frozen ovarian tissue samples taken from 22 patients with ovarian cancer between 1994 and 1998 were analyzed. Patients whose ovarian cancer actually demonstrated growth during platinum-combination treatment or no objective evidence of regression following four to six cycles of therapy were considered to have clinically defined platinum-resistant disease. QuMA was carried out at the following loci using the ABI Prism 7700 (TaqMan) instrument with a microsatellite repeat probe: D3S1553, D3S1617, D5S464, D5S630, D6S1581, D6S446, D8S557, D19S208, D20S196, DXS1068. Fisher's exact test, exact logistic regression, and the Cochran-Armitage trend test were used. Because of multiple hypothesis testing, the P values were adjusted with the Bonferroni procedure to limit the familywise error rate to at most 5%. RESULTS: Of the 22 patients, 12 (54.5%) were platinum-sensitive and 10 (45.5%) were platinum-resistant. When comparing sensitive and resistant patients, no statistically significant difference was noted among stage, grade, histology, and age (P = 0.1292, P = 1.0000, P = 1.0000, P = 1.0000, respectively). In the QuMA analysis, 10 of the 14 (71.4%) patients who had a low copy number of D6S1581 were platinum-resistant, while none of the patients with a normal or high copy number of D6S1581 were platinum-resistant. This was statistically significant when the marker data were treated as either a continuous or a categorical variable (P = 0.0410 and P = 0.0170, respectively). No other loci correlated significantly with platinum resistance. CONCLUSIONS: D6S1581 was the only genetic marker, of those examined, significantly related to chemoresistance. Patients with a loss of D6S1581 are more likely to be platinum-resistant. Identification of genetic alterations associated with platinum resistance detected by QuMA may contribute to a better understanding of clinical behavior and chemotherapy treatment options for patients.


Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Adenocarcinoma/patologia , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Repetições de Microssatélites/genética , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Hibridização de Ácido Nucleico , Neoplasias Ovarianas/patologia
10.
Br J Cancer ; 88(2): 223-30, 2003 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-12610507

RESUMO

A subset of circulating T cells (CD8(+)CD45RO(-)CD27(-)) with a naïve phenotype, but mediating effector function, is considered to play an important role in host antitumour defence. To investigate the attributes of these effector T cells in patients with squamous cell carcinoma (SCC) of the head and neck cancer, venous blood was obtained from 39 individuals with cancer and 45 normal controls (NC). Peripheral blood mononuclear cells were isolated, stained with labelled monoclonal antibodies specific for CD8, CD45RO, CD45RA, CD62L, CD27, TCR-zeta as well as isotype controls and examined by multicolour flow cytometry. Annexin V binding to CD8(+) T cells and PMA/ionomycin-induced IFN-gamma expression were also evaluated in patients and NC. The proportions of CD45RA(+)CD45RO(-) (naïve) and CD45RA(-)CD45RO(+) (memory) cells were found to be comparable within the CD8(+) T-cell subset. However, relative to NC, the frequency of effector CD8(+)CD45RO(-)CD27(-) cells was strikingly increased in all SCC patients regardless of the disease status (P=0.0003). The proportion of these cells was found to increase with age in both patients and NC. In NC, stimulated IFN-gamma expression was largely restricted to CD8(+)CD45RO(-)CD27(+) cells, while in patients CD8(+)CD45RO(-)CD27(-) expressed IFN-gamma after ex vivo stimulation. Expression of the TCR-associated zeta chain was decreased or absent in freshly isolated CD8(+)CD45RO(-)CD27(-) T cells in patients (P<0.0001). Annexin V was found to bind to a higher proportion of circulating CD8(+) T cells in patients than NC (P<0.006), and significantly more Annexin V(+) T cells were present in the effector (P<0.0059) than the naïve subset within the CD8(+)CD45RO(-) compartment. The data indicate that the expanded CD8(+)CD45RO(-)CD27(-) T cells, which contain precursors of IFN-gamma-producing T cells, are zeta-negative and sensitive to apoptosis in the circulation of patients with HNC.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Carcinoma de Células Escamosas/imunologia , Neoplasias de Cabeça e Pescoço/imunologia , Antígenos Comuns de Leucócito/imunologia , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Anexina A5/metabolismo , Apoptose , Linfócitos T CD8-Positivos/patologia , Carcinógenos/farmacologia , Carcinoma de Células Escamosas/patologia , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Citometria de Fluxo , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Memória Imunológica , Interferon gama/metabolismo , Ionomicina/farmacologia , Ionóforos/farmacologia , Masculino , Pessoa de Meia-Idade , Receptores de Antígenos de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/imunologia , Acetato de Tetradecanoilforbol/farmacologia
11.
Br J Cancer ; 86(2): 168-78, 2002 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-11870501

RESUMO

Circulating T lymphocytes of patients with prostate cancer have been reported to have functional deficits, including low or absent zeta-chain expression. To determine whether these functional impairments could be reversed by prostate specific antigen-based vaccination therapy, 10 patients treated with recombinant human prostate specific antigen plus GM-CSF and eight others receiving prostate specific antigen plus oil emulsion in two pilot clinical trials were evaluated prior to and after vaccination for several immunologic end points, including zeta-chain expression and cytokine production by circulating T cells as well as the frequency of T cells able to respond to prostate specific antigen in ELISPOT assays. The flow cytometry assay for zeta-chain expression was standardized to allow for a reliable comparison of pre- vs post-vaccination samples. Prior to therapy, the patients were found to have significantly lower zeta-chain expression in circulating CD3(+) cells and a higher percentage of zeta-chain negative CD3(+) and CD4(+) cells than normal donors. The patients' peripheral blood mononuclear cells spontaneously produced more IL-10 ex vivo than those of normal controls. After vaccination, recovery of zeta-chain expression was observed in 50% of patients in both clinical trials. Also, spontaneous IL-10 secretion by peripheral blood mononuclear cells decreased following immunotherapy in patients treated with prostate specific antigen and GM-CSF. The frequency of prostate specific antigen-reactive T cells was detectable in 7 out of 18 patients vs 4 out of 18 patients prior to vaccination. Only one of 18 patients was a clinical responder. The vaccine had stimulatory effects on the patients' immune system, but post-vaccine immune recovery could not be correlated to progression-free survival in this small cohort of patients with prostate cancer.


Assuntos
Vacinas Anticâncer/imunologia , Carcinoma/imunologia , Globinas/biossíntese , Interleucina-10/biossíntese , Antígeno Prostático Específico/imunologia , Antígeno Prostático Específico/uso terapêutico , Neoplasias da Próstata/imunologia , Linfócitos T/imunologia , Idoso , Carcinoma/tratamento farmacológico , Intervalo Livre de Doença , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/terapia , Resultado do Tratamento
12.
Clin Cancer Res ; 7(12): 4041-8, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11751499

RESUMO

PURPOSE: In esophageal cancer, lymph node metastases are the strongest predictor of recurrence and poor outcome. However, many node-negative patients still recur despite a potentially curative resection. This is probably the result of microscopically occult metastases missed by histological examination. In this study, we used both standard, gel-based reverse transcription-PCR (RT-PCR) and Taqman quantitative RT-PCR (QRT-PCR) for carcinoembryonic antigen (CEA) mRNA to detect occult micrometastases in 387 lymph nodes from 30 histologically node-negative esophageal cancer patients. EXPERIMENTAL DESIGN: CEA expression was compared with clinical outcomes to determine correlation with disease recurrence. For quantitative data, an optimum CEA expression level cutoff value was defined as the value that most accurately classified patients on the basis of disease recurrence. Kaplan-Meier survival curves were generated, and multivariate analyses were performed to evaluate the prognostic value of QRT-PCR. RESULTS: CEA expression levels were above the optimum cutoff level in 12 tissue blocks, resulting in the identification of 11 CEA-positive patients. Of these patients, 9 suffered disease recurrence and 2 remain disease free. Of the 19 CEA-negative patients, there was 1 disease recurrence. The sensitivity and specificity for predicting disease recurrence were 90 and 90%, respectively. Kaplan-Meier analysis showed that CEA positivity resulted in significantly lower disease-free and overall survival (P <0.0001 and 0.0006 respectively). In multivariate analyses, CEA positivity measured by QRT-PCR was the strongest independent predictor of disease recurrence among other clinical and pathological factors examined. CONCLUSIONS: QRT-PCR offers significant benefits over standard RT-PCR and identifies node-negative patients at high risk for recurrence.


Assuntos
Antígeno Carcinoembrionário/genética , Neoplasias Esofágicas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Idoso , Biomarcadores Tumorais/genética , Intervalo Livre de Doença , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Feminino , Seguimentos , Humanos , Linfonodos/patologia , Metástase Linfática , Masculino , Análise Multivariada , Metástase Neoplásica , Estadiamento de Neoplasias , Prognóstico , Recidiva , Sensibilidade e Especificidade , Taxa de Sobrevida , Fatores de Tempo
13.
Ann Thorac Surg ; 72(4): 1130-5, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11603424

RESUMO

BACKGROUND: Barrett's esophagus (BE) may progress to adenocarcinoma through dysplastic progression. Classification of dysplasia in BE has significant interobserver variability. Our objective was to determine whether genetic alterations in BE correlate with degrees of histologic dysplasia. METHODS: Fixed tissue from 37 patients with BE and adenocarcinoma was studied for six tumor suppressor genes. Tissues were microdissected and analyzed for loss of heterozygosity. Microdissection of individual crypts showing metaplasia and dysplasia were performed and analyzed for 23 of the 37 patients whose tumors were heterozygous for at least four of the six genes studied. RESULTS: Frequency of alterations for MXI1, hOGG1, p53, MTS1, DCC, and APC were 7 of 32 (22%), 12 of 35 (34%), 12 of 26 (46%), 17 of 30 (57%), 17 of 27 (63%), and 23 of 36 (64%), respectively. Analysis of BE demonstrated that crypts with metaplasia, low-grade dysplasia, and high-grade dysplasia strongly correlated with alterations in tumor suppressor genes (p < 0.0001). CONCLUSIONS: This pilot study demonstrates that genetic analysis can be performed on individual crypts in patients with BE, and that alterations may facilitate objective classification of the severity of dysplasia.


Assuntos
Adenocarcinoma/genética , Esôfago de Barrett/genética , Transformação Celular Neoplásica/genética , Análise Mutacional de DNA , Neoplasias Esofágicas/genética , Genes Supressores de Tumor/fisiologia , Adenocarcinoma/patologia , Esôfago de Barrett/patologia , Transformação Celular Neoplásica/patologia , Neoplasias Esofágicas/patologia , Esôfago/patologia , Genótipo , Humanos , Perda de Heterozigosidade/genética , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
14.
Surgery ; 130(4): 620-6; discussion 626-8, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11602892

RESUMO

BACKGROUND: Conclusive evidence supporting the routine use of multimodality therapy in esophageal cancer is lacking. However, since long-term survival after esophagectomy alone is unusual, clinical trials designed to identify effective therapeutic regimens are essential. We report here the 5-year results of a phase II induction chemoradiotherapy trial. METHODS: From August 1991 to January 1995, 44 patients with esophageal or gastroesophageal junction carcinoma were treated with a combination of 5-fluorouracil, cisplatin, and interferon-alpha with concurrent external beam radiotherapy. RESULTS: Forty-one (93%) patients completed chemoradiotherapy, with most toxic events recorded as grade I or II. Curative resection (all gross tumor removed) was achieved in 36 of 37 surgical explorations, with 10 tumors demonstrating complete pathologic response and 23 showing partial pathologic response. Median follow-up for survivors was 75 months (range, 60-100 months). Five-year survival for all patients was 32%, with a median survival of 28 months. Five-year disease-free survival in patients with curative resection was 36% (median, 26 months) and overall survival was 39% (median, 34 months). Five-year survival for patients with curative resection whose disease responded to chemoradiotherapy was 42% (median overall survival, 36 months). Local-regional recurrence alone occurred in 3 patients, distant failure alone in 12 patients, and combined local-regional and distant failure in 2 patients. A Cox proportional hazards model identified both pathologic tumor and nodal stage as independent predictors of disease-free survival. Fourteen patients (32%) were 5-year survivors; 1 of these patients later experienced disease recurrence and died. CONCLUSIONS: Preoperative chemoradiotherapy can result in a long-term and durable disease-free state. Only large, multi-institutional phase III trials can determine whether combined modality therapy is superior to resection alone.


Assuntos
Neoplasias Esofágicas/terapia , Adulto , Idoso , Terapia Combinada , Neoplasias Esofágicas/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Falha de Tratamento
15.
Arch Surg ; 136(7): 737-42; discussion 743, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11448381

RESUMO

HYPOTHESIS: Long-term survival is rare in patients treated for esophageal carcinoma. Several clinical trials suggest the possibility of prolonged survival in patients who undergo induction chemoradiotherapy plus esophagectomy. DESIGN: Prospective uncontrolled study. SETTING: University hospital. PATIENTS AND METHODS: Forty-four patients with carcinoma of the esophagus or gastroesophageal junction were prospectively entered into a phase II trial of preoperative 5-fluorouracil, cisplatin, and interferon alfa with concurrent external beam radiotherapy before esophagectomy. Curative resection was performed on 36 of 41 patients who completed the induction chemoradiotherapy. RESULTS: Of the 44 patients, 17 are alive at a median follow-up of 50 months. Of these 17 patients, 15 show no evidence of recurrent disease. Of the 14 patients with long-term survival (> or =3 years), 1 patient died of disease, and another patient is alive with disease. The remaining 12 patients are alive and disease-free (median follow-up, 54 months). Six patients have survived longer than 4 years and 3 patients longer than 5 years. Subsequent primary tumors have developed in 2 patients. One patient had a recurrence at 11 months following initiation of treatment and remains disease-free 43 months postresection of a single brain metastasis. Standard clinicopathologic parameters (age, sex, histologic findings, chemoradiotherapy regimen, and clinical and pathologic stages) were not significantly associated with a survival time of 3 years or longer (Fisher exact test, 2-tailed). Although not significant, p 53 mutational status suggested long-term survival. In 11 of 14 patients who are alive with no history of recurrence, p53 genotyping demonstrated no point mutations in 10 patients. Median survival time for the long-term survivors has not been reached. CONCLUSIONS: Long-term survival can be achieved in patients with esophageal carcinoma who undergo induction chemoradiotherapy and esophagectomy. Recurrence is unlikely in patients who survive for 3 years or longer after undergoing this multimodality treatment.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma/tratamento farmacológico , Carcinoma/radioterapia , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/radioterapia , Esofagectomia , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/radioterapia , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma/cirurgia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Quimioterapia Adjuvante , Cisplatino/administração & dosagem , Intervalo Livre de Doença , Fracionamento da Dose de Radiação , Esquema de Medicação , Neoplasias Esofágicas/cirurgia , Feminino , Fluoruracila/administração & dosagem , Humanos , Interferon-alfa/administração & dosagem , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Estudos Prospectivos , Radioterapia Adjuvante , Indução de Remissão , Análise de Sobrevida , Resultado do Tratamento
16.
Clin Cancer Res ; 7(3 Suppl): 947s-957s, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11300496

RESUMO

Expression of T-cell receptor- or Fcgamma receptor III-associated signal-transducing zeta chain is important for the functional integrity of immune cells. We found that significantly higher proportions of circulating CD3+ T cells as well as natural killer cells had low or absent expression of the zeta chain in patients with advanced melanoma than in normal donors (P < 0.0005). Decreased zeta expression was always observed in a small subset of circulating CD3+ T cells that were in the process of apoptosis, i.e., bound Annexin V or were terminal deoxynucleotidyl transferase-mediated nick end labeling positive. Up to 80% of T cells in the peripheral blood of patients with melanoma were Fas+, with the mean percentage of Fas+CD3+ cells significantly higher in patients (P < 0.004) than normal controls. These Fas+CD3+ T cells were found to preferentially undergo apoptosis. Annexin V binding, the loss of Fas expression from the cell surface as well as zeta down-regulation, which are associated with early apoptosis, were detected in a proportion of circulating Fas+CD3+. In Jurkat cells incubated with agonistic anti-Fas antibody (CH-11), a rapid loss of Fas expression from the cell surface coincided with Annexin V binding and preceded the loss of zeta chain during early apoptosis. In a subset of Jurkat cells coincubated with human melanoma cells, Annexin V binding and zeta degradation as well as DNA fragmentation were observed, indicating that the tumor induced T-cell death. Triggering of death receptors expressed on activated T lymphocytes was accompanied by the loss of zeta expression. On the other hand, soluble factors secreted by melanoma cells induced down-regulation but no apoptosis in activated normal T cells. In the circulation of patients with melanoma, apoptosis of immune effector cells may be related to the state of chronic activation, resulting in the up-regulation of death receptors and increased susceptibility to apoptosis.


Assuntos
Apoptose , Complexo CD3/biossíntese , Melanoma/sangue , Melanoma/patologia , Proteínas de Membrana/biossíntese , Receptores de Antígenos de Linfócitos T/biossíntese , Linfócitos T/metabolismo , Anexina A5/metabolismo , Antígenos CD4/biossíntese , Antígeno CD56/biossíntese , Antígenos CD8/biossíntese , Técnicas de Cocultura , Fragmentação do DNA , Regulação para Baixo , Citometria de Fluxo , Humanos , Marcação In Situ das Extremidades Cortadas , Células Jurkat , Leucócitos Mononucleares/metabolismo , Melanoma/metabolismo , Transdução de Sinais , Fatores de Tempo , Células Tumorais Cultivadas , Regulação para Cima , Receptor fas/biossíntese , Receptor fas/imunologia , Receptor fas/metabolismo
17.
Laryngoscope ; 111(2): 329-35, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11210884

RESUMO

OBJECTIVES/HYPOTHESIS: Patients undergoing contaminated head and neck surgery with flap reconstruction have wound infection rates of 20% to 25% with parenteral antibiotic prophylaxis. Studies suggest that perioperative antimicrobial mouthwash reduces oropharyngeal flora and may prevent wound infections. We hypothesized that the addition of topical antibiotics to a parenteral prophylactic regimen would reduce the incidence of wound infection in these high-risk patients. STUDY DESIGN: We performed a randomized, prospective clinical trial. METHODS: Patients received either 1) parenteral piperacillin/tazobactam (3.375 g every 6 hours for 48 h) or 2) parenteral piperacillin/tazobactam plus topical piperacillin/tazobactam administered as a mouthwash immediately before surgery and once a day for 2 days postoperatively, with piperacillin/tazobactam added to the intraoperative irrigation solution. The wounds of all patients were evaluated daily using predefined objective criteria. RESULTS: Sixty-two patients met inclusion criteria and were enrolled in the study. The overall wound infection rate was 8.1% (95% confidence interval [CI], 2.7%-17.8%). Two of 31 patients (6.4%) who received parenteral antibiotics alone developed a wound infection compared with 3 of 31 patients (9.7%) randomly assigned to receive topical plus parenteral antibiotics. This difference was not statistically significant (P = >.05). Infection rate was not associated with flap type (rotational vs. free tissue transfer), mandibular reconstruction, age, gender, tumor site, stage, surgical duration, or blood loss. CONCLUSIONS: These results suggest that piperacillin/tazobactam is a highly effective antibiotic for prevention of wound infection in patients undergoing flap reconstruction following contaminated head and neck surgery. However, the addition of topical piperacillin/tazobactam does not appear to enhance the prophylactic benefit of parenteral antibiotics alone.


Assuntos
Antibioticoprofilaxia , Neoplasias Otorrinolaringológicas/cirurgia , Ácido Penicilânico/análogos & derivados , Retalhos Cirúrgicos , Infecção da Ferida Cirúrgica/prevenção & controle , Administração Tópica , Adulto , Idoso , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Antissépticos Bucais , Ácido Penicilânico/administração & dosagem , Ácido Penicilânico/efeitos adversos , Piperacilina/administração & dosagem , Piperacilina/efeitos adversos , Estudos Prospectivos , Tazobactam , Irrigação Terapêutica
18.
Int J Oncol ; 18(3): 479-85, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11179475

RESUMO

Nasopharyngeal carcinoma (NPC) is characterized by its association with Epstein-Barr virus (EBV) infection. Unlike other upper aerodigestive tract squamous cell carcinomas, clinical and pathologic features are unable to predict outcome in NPC. EBV has been demonstrated to have transforming potential in B-cell systems so that its infection can rapidly and efficiently induce sustained lymphocyte proliferation in vitro. However, the relationship between cell proliferation and EBV infection in NPC has not been previously reported. This study was designed to determine the association of EBV infection and NPC tumor cell proliferation. Cell proliferation index, as measured by two markers, PCNA and Ki-67, were moderately correlated (r=0.534, p=0.033). Quantitative analysis of EBV positivity was highly correlated with both cell proliferation indices (r=0.802, p=0.0039 and r=0.720, p=0.0174 for PCNA and Ki-67, respectively). TNM staging did not demonstrate prognostic significance. NPC patients whose tumors were EBV positive demonstrated increased survival compared with patients whose tumors were EBV negative (p=0.043). These results indicate that EBV infection may regulate cell proliferation in NPC and the presence of EBV can be used as a positive prognostic factor.


Assuntos
Carcinoma de Células Escamosas/virologia , Divisão Celular/fisiologia , Infecções por Vírus Epstein-Barr/virologia , Herpesvirus Humano 4/fisiologia , Neoplasias Nasofaríngeas/virologia , Adulto , Idoso , Southern Blotting , Carcinoma de Células Escamosas/patologia , Infecções por Vírus Epstein-Barr/patologia , Feminino , Expressão Gênica , Genes Virais , Humanos , Técnicas Imunoenzimáticas , Hibridização In Situ , Antígeno Ki-67/metabolismo , Masculino , Pessoa de Meia-Idade , Neoplasias Nasofaríngeas/patologia , Estadiamento de Neoplasias , Antígeno Nuclear de Célula em Proliferação/metabolismo
19.
Clin Cancer Res ; 6(7): 2794-802, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10914726

RESUMO

The expression of human leukocyte antigen (HLA) class I molecules on the cell surface is necessary for the presentation of peptide antigens to cytotoxic CD8+ T lymphocytes of the immune system. Down-regulation of HLA class I gene expression has been implicated in tumorigenesis, including squamous cell carcinoma of the head and neck (SCCHN). Loss of MHC class I antigens may be one mechanism by which tumor cells escape immune detection. We performed prospective immunostaining of 26 primary SCCHN tumors and samples of normal mucosa harvested several centimeters away from the primary tumor, using a large panel of antibodies directed against allele-specific as well as monomorphic determinants of HLA class I molecules. Loss of expression of HLA class I proteins in the tumor was found in 50% (13 of 26) of primary tumors and was highly correlated with HLA loss in the corresponding normal mucosa (P < 0.0001). Further analysis demonstrated that the loss of HLA class I expression in the tumor was significantly associated with regional lymph node metastases (nodal stage; P = 0.0388), and that the number of HLA class I alleles lost in the normal mucosa was associated with subsequent development of a new primary aerodigestive tract cancer (P = 0.042). A patient with two metachronous cancers available for analysis had no evidence of HLA loss in the first tumor, demonstrated allelic loss in the second cancer, and subsequently died of disease. These results suggest that the loss of expression of HLA class I alleles may have prognostic implications.


Assuntos
Carcinoma de Células Escamosas/genética , Genes MHC Classe I , Neoplasias de Cabeça e Pescoço/genética , Antígenos de Histocompatibilidade Classe I/análise , Perda de Heterozigosidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Carcinoma de Células Escamosas/imunologia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/terapia , Terapia Combinada , Feminino , Haplótipos , Neoplasias de Cabeça e Pescoço/imunologia , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/terapia , Antígenos de Histocompatibilidade Classe I/genética , Teste de Histocompatibilidade , Humanos , Masculino , Pessoa de Meia-Idade , Mucosa/imunologia , Mucosa/patologia , Estadiamento de Neoplasias
20.
Med Dosim ; 25(2): 77-80, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10856685

RESUMO

In traditional brachytherapy for carcinoma of the cervix, doses are often prescribed to specifically chosen points (A and B) and the normal tissue tolerance calculated at specific reference points in the bladder and rectum. These tolerance doses are often used to modify the brachytherapy treatment plan. It is inherently assumed that the position of the brachytherapy applicator does not change in relation to the relevant anatomical structures over the time-course of an implant. To assess the accuracy of this assumption, 2 sets of localization films were obtained for each implant in 28 patients, 1 prior to loading and another after the removal of the radioactive sources. Significant applicator movement and, consequently, significant dose variations were ob: served. Therefore, isolated one-time dose measurements to normal critical structures should not be used as the sole basis for making therapeutic decisions. The magnitude of dose variations and their clinical significant are discussed.


Assuntos
Braquiterapia , Dosagem Radioterapêutica , Neoplasias do Colo do Útero/radioterapia , Feminino , Humanos
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