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1.
J Clin Oncol ; 28(17): 2839-46, 2010 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-20458040

RESUMO

PURPOSE: Apoptosis ligand 2/tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL)-a member of the tumor necrosis factor cytokine family-induces apoptosis by activating the extrinsic pathway through the proapoptotic death receptors DR4 and DR5. Recombinant human Apo2L/TRAIL (rhApo2L/TRAIL) has broad potential as a cancer therapy. To the best of our knowledge, this is the first in-human clinical trial to assess the safety, tolerability, pharmacokinetics, and antitumor activity of multiple intravenous doses of rhApo2L/TRAIL in patients with advanced cancer. PATIENTS AND METHODS: This phase I, open-label, dose-escalation study treated patients with advanced cancer with rhApo2L/TRAIL doses ranging from 0.5 to 30 mg/kg/d, with parallel dose escalation for patients without liver metastases and with normal liver function (cohort 1) and for patients with liver metastases and normal or mildly abnormal liver function (cohort 2). Doses were given daily for 5 days, with cycles repeating every 3 weeks. Assessments included adverse events (AEs), laboratory tests, pharmacokinetics, and imaging to evaluate antitumor activity. RESULTS: Seventy-one patients received a mean of 18.3 doses; seven patients completed all eight treatment cycles. The AE profile of rhApo2L/TRAIL was similar in cohorts 1 and 2. The most common AEs were fatigue (38%), nausea (28%), vomiting (23%), fever (23%), anemia (18%), and constipation (18%). Liver enzyme elevations were concurrent with progressive metastatic liver disease. Two patients with sarcoma (synovial and undifferentiated) experienced serious AEs associated with rapid tumor necrosis. Two patients with chondrosarcoma experienced durable partial responses to rhApo2L/TRAIL. CONCLUSION: At the tested schedule and dose range, rhApo2L/TRAIL was safe and well tolerated. Dose escalation achieved peak rhApo2L/TRAIL serum concentrations equivalent to those associated with preclinical antitumor efficacy.


Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Apoptose/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Ligante Indutor de Apoptose Relacionado a TNF/administração & dosagem , Adulto , Idoso , Antineoplásicos/farmacocinética , Estudos de Coortes , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/patologia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/farmacocinética , Ligante Indutor de Apoptose Relacionado a TNF/efeitos adversos , Ligante Indutor de Apoptose Relacionado a TNF/farmacocinética
2.
Ann Intern Med ; 150(1): 1-8, 2009 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-19075198

RESUMO

BACKGROUND: Colonoscopy is advocated for screening and prevention of colorectal cancer (CRC), but randomized trials supporting the benefit of this practice are not available. OBJECTIVE: To evaluate the association between colonoscopy and CRC deaths. DESIGN: Population-based, case-control study. SETTING: Ontario, Canada. PATIENTS: Persons age 52 to 90 years who received a CRC diagnosis from January 1996 to December 2001 and died of CRC by December 2003. Five controls matched by age, sex, geographic location, and socioeconomic status were randomly selected for each case patient. MEASUREMENTS: Administrative claims data were used to detect exposure to any colonoscopy and complete colonoscopy (to the cecum) from January 1992 to an index date 6 months before diagnosis in each case patient and the same assigned date in matched controls. Exposures in case patients and controls were compared by using conditional logistic regression to control for comorbid conditions. Secondary analyses were done to see whether associations differed by site of primary CRC, age, or sex. RESULTS: 10 292 case patients and 51 460 controls were identified; 719 case patients (7.0%) and 5031 controls (9.8%) had undergone colonoscopy. Compared with controls, case patients were less likely to have undergone any attempted colonoscopy (adjusted conditional odds ratio [OR], 0.69 [95% CI, 0.63 to 0.74; P < 0.001]) or complete colonoscopy (adjusted conditional OR, 0.63 [CI, 0.57 to 0.69; P < 0.001]). Complete colonoscopy was strongly associated with fewer deaths from left-sided CRC (adjusted conditional OR, 0.33 [CI, 0.28 to 0.39]) but not from right-sided CRC (adjusted conditional OR, 0.99 [CI, 0.86 to 1.14]). LIMITATION: Screening could not be differentiated from diagnostic procedures. CONCLUSION: In usual practice, colonoscopy is associated with fewer deaths from CRC. This association is primarily limited to deaths from cancer developing in the left side of the colon.


Assuntos
Colonoscopia , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Colo/patologia , Neoplasias Colorretais/diagnóstico , Comorbidade , Detecção Precoce de Câncer , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Ontário/epidemiologia , Análise de Regressão
3.
J Clin Epidemiol ; 61(3): 295-300, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18226754

RESUMO

OBJECTIVE: We examined the impact on statistical inference when a chi(2) test is used to compare the proportion of successes in the level of a categorical variable that has the highest observed proportion of successes with the proportion of successes in all other levels of the categorical variable combined. STUDY DESIGN AND SETTING: Monte Carlo simulations and a case study examining the association between astrological sign and hospitalization for heart failure. RESULTS: A standard chi(2) test results in an inflation of the type I error rate, with the type I error rate increasing as the number of levels of the categorical variable increases. Using a standard chi(2) test, the hospitalization rate for Pisces was statistically significantly different from that of the other 11 astrological signs combined (P=0.026). After accounting for the fact that the selection of Pisces was based on it having the highest observed proportion of heart failure hospitalizations, subjects born under the sign of Pisces no longer had a significantly higher rate of heart failure hospitalization compared to the other residents of Ontario (P=0.152). CONCLUSIONS: Post hoc comparisons of the proportions of successes across different levels of a categorical variable can result in incorrect inferences.


Assuntos
Astrologia , Insuficiência Cardíaca/epidemiologia , Fatores de Confusão Epidemiológicos , Métodos Epidemiológicos , Insuficiência Cardíaca/etiologia , Hospitalização/estatística & dados numéricos , Humanos , Ontário/epidemiologia
4.
N Engl J Med ; 357(25): 2552-61, 2007 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-18094376

RESUMO

BACKGROUND: The abrogation of function of the tumor-suppressor protein p53 as a result of mutation of its gene, TP53, is one of the most common genetic alterations in cancer cells. We evaluated TP53 mutations and survival in patients with squamous-cell carcinoma of the head and neck. METHODS: A total of 560 patients with squamous-cell carcinoma of the head and neck who were treated surgically with curative intent were enrolled in our prospective multicenter, 7-year study. TP53 mutations were analyzed in DNA from the tumor specimens with the use of the Affymetrix p53 chip and the Surveyor DNA endonuclease and denaturing high-performance liquid chromatography. Mutations were classified into two groups, disruptive and nondisruptive, according to the degree of disturbance of protein structure predicted from the crystal structure of the p53-DNA complexes. TP53 mutational status was compared with clinical outcome. RESULTS: TP53 mutations were found in tumors from 224 of 420 patients (53.3%). As compared with wild-type TP53, the presence of any TP53 mutation was associated with decreased overall survival (hazard ratio for death, 1.4; 95% confidence interval [CI], 1.1 to 1.8; P=0.009), with an even stronger association with disruptive mutations (hazard ratio, 1.7; 95% CI, 1.3 to 2.4; P<0.001) and no significant association with nondisruptive mutations (hazard ratio, 1.2; 95% CI, 0.9 to 1.7; P=0.16). In multivariate analyses a disruptive TP53 alteration, as compared with the absence of a TP53 mutation, had an independent, significant association with decreased survival (hazard ratio, 1.7; 95% CI, 1.2 to 2.4; P=0.003). CONCLUSIONS: Disruptive TP53 mutations in tumor DNA are associated with reduced survival after surgical treatment of squamous-cell carcinoma of the head and neck.


Assuntos
Carcinoma de Células Escamosas/genética , DNA de Neoplasias , Genes p53 , Neoplasias de Cabeça e Pescoço/genética , Mutação , Proteína Supressora de Tumor p53/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Análise Mutacional de DNA , DNA de Neoplasias/análise , Feminino , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Análise de Sequência com Séries de Oligonucleotídeos , Prognóstico , Modelos de Riscos Proporcionais , Estudos Prospectivos
5.
J Clin Oncol ; 25(25): 3971-7, 2007 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-17761982

RESUMO

PURPOSE: Taxane-based concurrent chemoradiotherapy (CCR) for head and neck cancers has proven to have a favorable toxicity profile compared with cisplatin and radiation. This phase II multi-institutional trial evaluates taxane-based induction chemotherapy followed by CCR for organ preservation in resectable stage III/IVA and IVB larynx and oropharynx (OP) cancer patients. PATIENTS AND METHODS: Eligibility required resectable stage T2N+, or T3-T4N0-3M0 biopsy-proven squamous carcinoma, age at least 18 years, PS 0 to 2, good organ function, and no prior chemotherapy or radiation. Treatment was induction paclitaxel 175 mg/m(2) and carboplatin area under the concentration-time curve (AUC) 6 for two cycles every 21 days followed by concurrent paclitaxel 30 mg/m(2) every 7 days with 70 Gy if no evidence of tumor progression. Weekly erythropoietin alpha 40 kU was used for suboptimal hemoglobin (< 14 gm/dL men, < 13 gm/dL women). The primary end point was organ preservation (freedom from primary site salvage surgery or primary tumor recurrence). RESULTS: One hundred five of 111 patients (36 larynx, 69 OP) were eligible. Median follow-up was 36.7 months. Ninety-four percent received full-dose radiotherapy and 91% received at least five cycles of concurrent paclitaxel. No patient progressed while receiving chemotherapy. Organ preservation was 81% at 2 years after completion of therapy (larynx 74%, OP 84%). Thirteen patients required primary-site salvage surgery (seven larynx, six OP), and six of these have progressed and died (three larynx, three OP). Thirteen patients developed distant metastases (seven larynx, six OP; P = .02) and 10 of 36 larynx and 11 of 69 OP patients have died as a result of their disease. Two-year survival is 76% (63% larynx v 83% OP). CONCLUSION: A high organ preservation rate was obtained with this regimen for OP but not for larynx patients. Toxicity was low, and induction chemotherapy did not preclude delivery of concurrent chemoradiotherapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/terapia , Neoplasias Laríngeas/terapia , Neoplasias Orofaríngeas/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Hidrocarbonetos Aromáticos com Pontes/administração & dosagem , Carcinoma de Células Escamosas/complicações , Carcinoma de Células Escamosas/patologia , Quimioterapia Adjuvante , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/prevenção & controle , Feminino , Seguimentos , Humanos , Neoplasias Laríngeas/complicações , Neoplasias Laríngeas/patologia , Laringectomia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Orofaríngeas/complicações , Neoplasias Orofaríngeas/patologia , Paclitaxel/administração & dosagem , Faringectomia , Platina/administração & dosagem , Radioterapia Adjuvante , Recuperação de Função Fisiológica , Terapia de Salvação , Distúrbios da Fala/etiologia , Distúrbios da Fala/prevenção & controle , Taxoides/administração & dosagem , Resultado do Tratamento
6.
Blood ; 110(5): 1607-11, 2007 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-17485550

RESUMO

In a prospective trial in 284 children with B-lineage acute lymphoblastic leukemia (ALL), we assessed the clinical utility of real-time quantitative polymerase chain reaction analysis of antigen receptor gene rearrangements for detection of minimal residual disease (MRD) to identify children at high risk of relapse. At the end of induction therapy, the 5-year risk of relapse was 5% in 176 children with no detectable MRD and 44% in 108 children with detectable MRD (P < .001), with a linear association of the level of MRD and subsequent relapse. Recursive partitioning and clinical characteristics identified that the optimal cutoff level of MRD to predict outcome was 10(-3). The 5-year risk of relapse was 12% for children with MRD less than one leukemia cell per 10(3) normal cells (low MRD) but 72% for children with MRD levels greater than this level (high MRD) (P < .001) and children with high MRD had a 10.5-fold greater risk of relapse. Based upon these results we have altered our treatment regimen for children with B-lineage ALL and children with MRD levels greater than or equal to 10(-3) at the end of 4 weeks of multiagent induction chemotherapy now receive intensified treatment to attempt to decrease their risk of subsequent relapse.


Assuntos
Linfoma de Burkitt/mortalidade , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Linfoma de Burkitt/tratamento farmacológico , Linfoma de Burkitt/genética , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Seguimentos , Rearranjo Gênico do Linfócito T/genética , Humanos , Lactente , Masculino , Neoplasia Residual , Estudos Prospectivos , Receptores de Antígenos de Linfócitos T/genética , Recidiva , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Risco , Taxa de Sobrevida
7.
Blood ; 107(11): 4508-13, 2006 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-16493009

RESUMO

In a retrospective analysis, we previously reported that children whose leukemia cells harbored the TEL/AML1 gene rearrangement have excellent outcomes. From 1996 to 2000, we conducted a prospective study to determine the incidence and outcomes of children with TEL/AML1-positive acute lymphoblastic leukemia (ALL). Children with newly diagnosed ALL were treated on DFCI ALL Consortium Protocol 95-01. Patients were risk stratified primarily by current National Cancer Institute (NCI)-Rome risk criteria. With a median follow-up of 5.2 years, the 5-year event-free survival for TEL/AML1-positive patients was 89% compared with 80% for TEL/AML1-negative B-precursor patients (P = .05). The 5-year overall survival rate was 97% among TEL/AML-positive patients compared with 89% among TEL/AML1-negative patients (P = .03). However, in a multivariable analysis, risk group (age and leukocyte count at diagnosis) and asparaginase treatment group, but not TEL/AML1 status, were found to be independent predictors of outcome. We conclude that TEL/AML1-positive patients have excellent outcomes, confirming our previous findings. However, factors such as age at diagnosis and presenting leukocyte count should be taken into consideration when treating this group of patients.


Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/genética , Proteínas de Fusão Oncogênica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Fatores Etários , Asparaginase/uso terapêutico , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Contagem de Leucócitos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras B/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/mortalidade , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Prognóstico , Estudos Prospectivos , Fatores de Risco , Taxa de Sobrevida , Resultado do Tratamento
8.
J Clin Oncol ; 23(34): 8646-54, 2005 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-16314626

RESUMO

PURPOSE: Therapy of recurrent/metastatic squamous cell carcinoma of the head and neck results in median progression-free survival (PFS) of 2 months. These cancers are rich in epidermal growth factor receptor (EGFR). We wished to determine whether the addition of cetuximab, which inhibits activation of EGFR, would improve PFS. PATIENTS AND METHODS: Patients with recurrent/metastatic squamous cell carcinoma of the head and neck were randomly assigned to receive cisplatin every 4 weeks, with weekly cetuximab (arm A) or placebo (arm B). Tumor tissue was assayed for EGFR expression by immunohistochemistry. The primary end point was PFS. Secondary end points of interest were response rate, toxicity, overall survival, and correlation of EGFR with clinical end points. RESULTS: There were 117 analyzable patients enrolled. Median PFS was 2.7 months for arm B and 4.2 months for arm A. The hazard ratio for progression of arm A to arm B was 0.78 (95% CI, 0.54 to 1.12). Median overall survival was 8.0 months for arm B and 9.2 months for arm A (P = .21). The hazard ratio for survival by skin toxicity in cetuximab-treated patients was 0.42 (95% CI, 0.21 to 0.86). Objective response rate was 26% [corrected] for arm A and 10% [corrected] for arm B (P = .03). Enhancement of response was greater for patients with EGFR staining present in less than 80% of cells. CONCLUSION: Addition of cetuximab to cisplatin significantly improves response rate. There was a survival advantage for the development of rash. Progression-free and overall survival were not significantly improved by the addition of cetuximab in this study.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Cetuximab , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Estudos Cross-Over , Relação Dose-Resposta a Droga , Hipersensibilidade a Drogas/etiologia , Receptores ErbB/biossíntese , Feminino , Seguimentos , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Doenças Hematológicas/induzido quimicamente , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Recidiva Local de Neoplasia , Índice de Gravidade de Doença , Dermatopatias/induzido quimicamente , Análise de Sobrevida , Fatores de Tempo , Resultado do Tratamento
9.
Br J Haematol ; 131(2): 185-92, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16197448

RESUMO

Infant acute lymphoblastic leukaemia (ALL) represents a rare but unique subset with poor prognosis. We analysed mixed-lineage leukaemia (MLL) gene rearrangements and the sequences of complete and incomplete immunoglobulin heavy chain gene rearrangements (IGH) in 14 infants (age < or = 12 months at diagnosis) enrolled on Dana-Farber Cancer Institute ALL Consortium Protocol 95-01. The dynamics of the leukaemic clone were followed during the course of the disease by quantitative real-time polymerase chain reaction of IGH rearrangements. Sixteen sequences were obtained from 13 (93%) of these infants. There was marked over usage of the V(H)6.1 gene segment (64%) in infants compared with older children with ALL (8%), (P < 0.001) and overusage of D(H)6 (P = 0.004) and J(H)1 (P = 0.004). Poor outcome was associated with MLL gene rearrangements rather than any specific V(H)D(H)J(H) gene usage patterns. Levels of minimal residual disease (MRD) at the end of induction appeared to be high in infants with ALL compared with older children, and although the number of infant cases studied was small, there were no differences in MRD levels after induction therapy in infant ALL with or without MLL gene rearrangements (P = 0.41) and quantitative MRD assessment at the early time points may not be predictive of outcome. Novel treatment strategies are required to improve the outcome in this poor prognosis subset of children with ALL.


Assuntos
Rearranjo Gênico do Linfócito B , Genes de Imunoglobulinas , Leucemia de Células B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Antineoplásicos/uso terapêutico , Citogenética , Expressão Gênica , Humanos , Lactente , Leucemia de Células B/tratamento farmacológico , Leucemia de Células B/mortalidade , Neoplasia Residual/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Estudos Prospectivos , Indução de Remissão , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sobrevida
10.
J Clin Oncol ; 22(13): 2701-7, 2004 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-15226337

RESUMO

PURPOSE: We evaluated 8-year survival and late neuropsychologic toxicity in children with acute lymphoblastic leukemia treated in a randomized clinical trial to test whether hyperfractionated (twice daily) cranial radiation therapy (CRT) can reduce incidence and severity of late toxicities associated with 18 Gy of CRT. PATIENTS AND METHODS: Between 1987 and 1995, 369 children treated on two consecutive Dana-Farber Cancer Institute Consortium protocols for high-risk acute lymphoblastic leukemia were randomly assigned to conventionally fractionated CRT (CFX) or hyperfractionated CRT (HFX) to a total dose of 18 Gy. Neuropsychologic testing was completed for 125 of 287 children in continuous complete remission. Event-free and overall survival, as well as neuropsychologic function, were compared for the two arms of the protocol. RESULTS: Eight-year event-free survival (+/- SE) was 80% +/- 3% for children randomly assigned to CFX and 72% +/- 3% for HFX (P =.06). Overall survival was 85% +/- 3% for CFX and 78% +/- 3% for HFX (P =.06). CNS relapses occurred in 2.8% of patients receiving CFX and 2.7% receiving HFX (P =.99). Cognitive function for both groups was solidly in the average range, with no group differences in intelligence, academic achievement, visuospatial reasoning, or verbal learning. Children on the HFX arm exhibited a modest advantage for visual memory (P <.05). CONCLUSION: HFX provides no benefit in terms of cognitive late effects and may compromise antileukemic efficacy. HFX should not be substituted for conventionally dosed CRT in children who require radiation therapy for treatment of acute lymphoblastic leukemia.


Assuntos
Transtornos Cognitivos/etiologia , Irradiação Craniana/efeitos adversos , Irradiação Craniana/métodos , Transtornos da Memória/etiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/radioterapia , Lesões por Radiação/prevenção & controle , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Criança , Pré-Escolar , Transtornos Cognitivos/prevenção & controle , Intervalo Livre de Doença , Fracionamento da Dose de Radiação , Feminino , Humanos , Lactente , Masculino , Transtornos da Memória/prevenção & controle , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Fatores de Risco , Análise de Sobrevida
11.
Blood ; 103(12): 4602-9, 2004 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-15010366

RESUMO

Sequence analysis of the immunoglobulin heavy chain genes (IgH) has demonstrated preferential usage of specific variable (V), diversity (D), and joining (J) genes at different stages of B-cell development and in B-cell malignancies, and this has provided insight into B-cell maturation and selection. Knowledge of the association between rearrangement patterns based on updated databases and clinical characteristics of pediatric acute lymphoblastic leukemia (ALL) is limited. We analyzed 381 IgH sequences identified at presentation in 317 children with B-lineage ALL and assessed the V(H)D(H)J(H) gene utilization profiles. The D(H)J(H)-proximal V(H) segments and the D(H)2 gene family were significantly overrepresented. Only 21% of V(H)-J(H) joinings were potentially productive, a finding associated with a trend toward an increased risk of relapse. These results suggest that physical location at the V(H) locus is involved in preferential usage of D(H)J(H)-proximal V(H) segments whereas D(H) and J(H) segment usage is governed by position-independent molecular mechanisms. Molecular pathophysiology appears relevant to clinical outcome in patients who have only productive rearrangements, and specific rearrangement patterns are associated with differences in the tumor biology of childhood ALL.


Assuntos
Linfoma de Burkitt/imunologia , Cadeias Pesadas de Imunoglobulinas/genética , Região de Junção de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Adolescente , Linfócitos B/imunologia , Sequência de Bases , Linfoma de Burkitt/genética , Criança , Pré-Escolar , Aberrações Cromossômicas , Feminino , Rearranjo Gênico/genética , Humanos , Lactente , Masculino , Reação em Cadeia da Polimerase , Translocação Genética , VDJ Recombinases/genética
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