RESUMO
Genetic association studies suggest a genetic predisposition for cisplatin-induced ototoxicity. Among other candidate genes, thiopurine methyltransferase (TPMT) is considered a critical gene for susceptibility to cisplatin-induced hearing loss in a pharmacogenetic guideline. The PanCareLIFE cross-sectional cohort study evaluated the genetic associations in a large pan-European population and assessed the diagnostic accuracy of the genetic markers. 1,112 pediatric cancer survivors who had provided biomaterial for genotyping were screened for participation in the pharmacogenetic association study. 900 participants qualified for inclusion. Based on the assessment of original audiograms, patients were assigned to three phenotype categories: no, minor, and clinically relevant hearing loss. Fourteen variants in eleven candidate genes (ABCC3, OTOS, TPMT, SLC22A2, NFE2L2, SLC16A5, LRP2, GSTP1, SOD2, WFS1, and ACYP2) were genotyped. The genotype and phenotype data represent a resource for conducting meta-analyses to derive a more precise pooled estimate of the effects of genes on the risk of hearing loss due to platinum treatment.
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BACKGROUND: Irreversible sensorineural hearing loss is a common side effect of platinum treatment with the potential to significantly impair the neurocognitive, social and educational development of childhood cancer survivors. Genetic association studies suggest a genetic predisposition for cisplatin-induced ototoxicity. Among other candidate genes, thiopurine methyltransferase (TPMT) is considered a critical gene for susceptibility to cisplatin-induced hearing loss in a pharmacogenetic guideline. The aim of this cross-sectional cohort study was to confirm the genetic associations in a large pan-European population and to evaluate the diagnostic accuracy of the genetic markers. METHODS: Eligibility criteria required patients to be aged less than 19 years at the start of chemotherapy, which had to include cisplatin and/or carboplatin. Patients were assigned to three phenotype categories: no, minor and clinically relevant hearing loss. Fourteen variants in eleven candidate genes (ABCC3, OTOS, TPMT, SLC22A2, NFE2L2, SLC16A5, LRP2, GSTP1, SOD2, WFS1 and ACYP2) were investigated. Multinomial logistic regression was performed to model the relationship between genetic predictors and platinum ototoxicity, adjusting for clinical risk factors. Additionally, measures of the diagnostic accuracy of the genetic markers were determined. RESULTS: 900 patients were included in this study. In the multinomial logistic regression, significant unique contributions were found from SLC22A2 rs316019, the age at the start of platinum treatment, cranial radiation and the interaction term [platinum compound]∗[cumulative dose of cisplatin]. The predictive performance of the genetic markers was poor compared with the clinical risk factors. CONCLUSIONS: PanCareLIFE is the largest study of cisplatin-induced ototoxicity to date and confirmed a role for the polyspecific organic cation transporter SLC22A2. However, the predictive value of the current genetic candidate markers for clinical use is negligible, which puts the value of clinical factors for risk assessment of cisplatin-induced ototoxicity back into the foreground.
Assuntos
Antineoplásicos/efeitos adversos , Sobreviventes de Câncer , Carboplatina/efeitos adversos , Cisplatino/efeitos adversos , Perda Auditiva Neurossensorial/genética , Audição/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Transportador 2 de Cátion Orgânico/genética , Variantes Farmacogenômicos , Polimorfismo de Nucleotídeo Único , Adolescente , Idade de Início , Criança , Pré-Escolar , Estudos Transversais , Europa (Continente) , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Perda Auditiva Neurossensorial/induzido quimicamente , Perda Auditiva Neurossensorial/fisiopatologia , Humanos , Lactente , Recém-Nascido , Masculino , Ototoxicidade , Testes Farmacogenômicos , Estudos Prospectivos , Estudos Retrospectivos , Medição de Risco , Fatores de RiscoRESUMO
AIMS: Survival after cancer diagnosed during childhood or adolescence continues to improve with new treatments and supportive therapies. Optimal long-term care requires that risks to vulnerable organs are clearly defined and translated into guidelines that are implemented into practice. PanCareLIFE is a pan-European consortium that addresses survivorship issues comprising fertility, hearing impairment and quality of life. This article describes the scientific basis of PanCareLIFE's studies. METHODS: PanCareLIFE involves 17 partner institutions from eight European countries, with additional 11 data providers from five other countries. Study designs and methods include molecular genetic, cohort and case-control studies, a longitudinal study and an intervention study. Ethics and data protection issues have been taken into account from the beginning. RESULTS: PanCareLIFE will investigate the way that treatment impairs female fertility, by evaluating anti-Müllerian hormone levels and the underlying genetic susceptibility to loss of fertility. For our fertility studies, more than 6000 survivors have completed questionnaires, more than 1500 provided serum samples and more than 400 case-control triads have been identified. Fertility preservation guidelines for boys and girls will be developed. More than 2000 survivors have contributed audiograms for the ototoxicity study. Almost 1000 samples were sent for genetic analysis related to ototoxicity and gonadal reserve. The SF-36 questionnaire will measure quality of life in more than 10,000 survivors. CONCLUSIONS: The large number of subjects enrolled in PanCareLIFE and the detailed information accumulated will allow in-depth evaluation of important outcomes. Fertility preservation guidelines will help patients and their families make informed decisions and contribute to their long-term well-being.
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Qualidade de Vida/psicologia , Adolescente , Adulto , Criança , Pré-Escolar , Europa (Continente) , Estudos de Viabilidade , Feminino , Preservação da Fertilidade , Humanos , Lactente , Recém-Nascido , Assistência de Longa Duração , Masculino , Neoplasias , Projetos Piloto , Sobreviventes , Adulto JovemRESUMO
In a multicenter study the authors prospectively investigated neurocognitive function in childhood ALL patients. Sixty-six patients (mean age at diagnosis 7.9 +/- 3.6 years, 34 female), treated with repeated intrathecal and systemical methotrexate administrations without cranial irradiation, underwent psychometric testing for intelligence, concentration, and visual-motor integration postdiagnosis and after reinduction therapy. Although there was a statistically significant decline of intellectual function after reinduction therapy for younger patients and girls (IQ scores still within normative data range), there were no differences in visual-motor performance and concentration over the time of induction therapy. Thus, neurocognitive examination should focus on younger ALL patients and girls.
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Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Transtornos Cognitivos/induzido quimicamente , Irradiação Craniana , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Asparaginase/efeitos adversos , Asparaginase/uso terapêutico , Criança , Pré-Escolar , Transtornos Cognitivos/fisiopatologia , Ciclofosfamida/efeitos adversos , Ciclofosfamida/uso terapêutico , Citarabina/efeitos adversos , Citarabina/uso terapêutico , Daunorrubicina/efeitos adversos , Daunorrubicina/uso terapêutico , Feminino , Seguimentos , Humanos , Injeções Espinhais , Testes de Inteligência , Estudos Longitudinais , Masculino , Mercaptopurina/efeitos adversos , Mercaptopurina/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Prednisolona/efeitos adversos , Prednisolona/uso terapêutico , Estudos Prospectivos , Desempenho Psicomotor/efeitos dos fármacos , Desempenho Psicomotor/fisiologia , Fatores de Risco , Vincristina/efeitos adversos , Vincristina/uso terapêuticoRESUMO
Survival after childhood cancer has improved substantially over recent decades. Although cancer in childhood is rare increasingly effective treatments have led to a growing number of long-term survivors. It is estimated that there are between 300,000 and 500,000 childhood cancer survivors in Europe. Such good survival prospects raise important questions relating to late effects of treatment for cancer. Research has shown that the majority will suffer adverse health outcomes and premature mortality compared with the general population. While chronic health conditions are common among childhood cancer survivors, each specific type of late effect is very rare. Long-term effects must be considered particularly when addressing complex multimodality treatments, and taking into account the interaction between aspects of treatment and genotype. The PanCare Network was set up across Europe in order to effectively answer many of these questions and thereby improve the care and quality of life of survivors. The need for a structured long-term follow-up system after childhood cancer has been recognised for some time and strategies for implementation have been developed, first nationally and then trans-nationally, across Europe. Since its first meeting in Lund in 2008, the goal of the PanCare Network has been to coordinate and implement these strategies to ensure that every European survivor of childhood and adolescent cancer receives optimal long-term care. This paper will outline the structure and work of the PanCare Network, including the results of several European surveys, the start of two EU-funded projects and interactions with relevant stakeholders and related projects.
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Neoplasias/mortalidade , Neoplasias/reabilitação , Sobreviventes/estatística & dados numéricos , Adolescente , Criança , Pré-Escolar , Europa (Continente)/epidemiologia , Feminino , Humanos , Assistência de Longa Duração , Masculino , Qualidade de Vida , Resultado do TratamentoAssuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/radioterapia , Osteossarcoma/tratamento farmacológico , Osteossarcoma/radioterapia , Vigilância da População/métodos , Lesões por Radiação/etiologia , Sistema de Registros , Sarcoma de Ewing/tratamento farmacológico , Sarcoma de Ewing/radioterapia , Sarcoma/tratamento farmacológico , Sarcoma/radioterapia , Sobreviventes/estatística & dados numéricos , Adolescente , Assistência ao Convalescente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Áustria , Cardiomiopatias/induzido quimicamente , Criança , Terapia Combinada , Estudos Transversais , Relação Dose-Resposta a Droga , Doxorrubicina/efeitos adversos , Doxorrubicina/uso terapêutico , Alemanha , Coração/efeitos da radiação , Humanos , Ifosfamida/efeitos adversos , Ifosfamida/uso terapêutico , Rim/efeitos da radiação , Necrose do Córtex Renal/induzido quimicamente , Estudos Multicêntricos como Assunto , Estudos Prospectivos , Qualidade de Vida , Lesões por Radiação/epidemiologia , Dosagem Radioterapêutica , Radioterapia Adjuvante , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , SuíçaAssuntos
Alocação de Recursos para a Atenção à Saúde/economia , Alocação de Recursos para a Atenção à Saúde/estatística & dados numéricos , Avaliação das Necessidades/economia , Neoplasias/economia , Neoplasias/reabilitação , Sobreviventes/estatística & dados numéricos , Custos de Cuidados de Saúde/estatística & dados numéricos , Humanos , Avaliação das Necessidades/estatística & dados numéricos , Neoplasias/epidemiologia , Revisão da Utilização de Recursos de SaúdeRESUMO
UNLABELLED: Precocious puberty is not a typical manifestation of patients with Klinefelter syndrome (KS). However, there is an increased incidence of mediastinal germ cell tumors (M-GCT) in KS, whereas the discussion of a generally higher tumor risk in this condition is still controversial. A rare subgroup of KS patients consists of prepubertal children with precocious puberty due to human chorionic gonadotropin (hCG)-producing M-GCTs. We present clinical data on a boy with KS and sexual precocity, and summarize the published data on 12 boys with KS out of 54 cases of KS and M-GCT. CLINICAL REPORT: an 8.5-year-old boy presented with signs of precocious puberty. Laboratory analyses (suppressed gonadotropins, elevated testosterone) and thoracic CT demonstrated a beta-human chorionic gonadotropin (beta-hCG) and alpha(1)-feto protein (alpha-FP) secreting mediastinal tumor. Histological analysis showed a mixed germ cell tumor comprising choriocarcinoma (CH), embryonal carcinoma (EC), mature teratoma (MT), and yolk sac tumor (YS). He was successfully treated by surgery and adjuvant chemotherapy. Epianalysis of published cases: all KS patients (n = 12), age 4-9 years, presented with precocious sexual development (PP), whereas the older ones showed thorax-associated symptoms, mainly chest pain, dyspnea, and cough. The histological distribution was also age-dependent with mixed germ cell tumors predominantly in younger patients. Thus, M-GCTs are strongly associated with precocious puberty in young boys with KS. Therefore, a karyotype analysis should be included in the clinical work-up of boys with precocious puberty and M-GCT. There is still no convincing explanation for the association of M-GCTs and KS.
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Síndrome de Klinefelter/complicações , Neoplasias do Mediastino/complicações , Neoplasias Embrionárias de Células Germinativas/complicações , Puberdade Precoce/complicações , Criança , Humanos , Cariotipagem , Síndrome de Klinefelter/genética , MasculinoRESUMO
BACKGROUND AND PURPOSE: Radiogenic late effects in children and adolescents have been evaluated retrospectively in most analyses, with small patient numbers. The German Group of Pediatric Radiation Oncology (APRO) has generated a concept for a prospective evaluation of radiation-associated late effects in childhood. The aim of this study was to evaluate the feasibility of a nationwide central database for the documentation of radiation parameters and side effects of all children treated within therapy protocols of the German Society of Pediatric Oncology and Hematology (GPOH). PATIENTS AND METHODS: A study center has been implemented in Muenster, the documentation has started in July 2001 in few centers in a pilot phase. Since February 2004 the documentation is done countrywide. Detailed documentation forms have been designed for treatment parameters and for doses applied at organs at risk. Furthermore, a uniform toxicity documentation, according to the RTOG/EORTC criteria, was chosen. Patients were reported from the study centers of the GPOH to the study center. All information was collected and analyzed in the study center. RESULTS: Till July 31, 2005, 438 documentations of radiation and 579 toxicity documentations of side effects have been collected in the study center. 46 centers for radiotherapy in Germany and one center each in Austria and in Switzerland took part in the documentation. The quality of documentation regarding completeness and plausibility fulfilled the expected criteria in most cases. This feasibility analysis showed that important information about organ dose levels and side effects was documented in a large number of patients (Figures 1 and 2). CONCLUSION: This prospective evaluation of radiotherapy and radiogenic side effects in children and adolescents will allow correlating doses at organs at risk and the incidence of acute and late sequelae in Germany. Further documentations and a longer follow-up are necessary to obtain powerful results.
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Neoplasias/radioterapia , Lesões por Radiação/etiologia , Radioterapia/efeitos adversos , Sistema de Registros , Adolescente , Fatores Etários , Áustria , Mama/efeitos da radiação , Criança , Radioisótopos de Cobalto/uso terapêutico , Bases de Dados como Assunto , Fracionamento da Dose de Radiação , Relação Dose-Resposta à Radiação , Elétrons/uso terapêutico , Estudos de Viabilidade , Feminino , Seguimentos , Alemanha , Coração/efeitos da radiação , Humanos , Incidência , Rim/efeitos da radiação , Pulmão/efeitos da radiação , Masculino , Estudos Multicêntricos como Assunto , Projetos Piloto , Estudos Prospectivos , Terapia com Prótons , Dosagem Radioterapêutica , Fatores de Risco , Coluna Vertebral/efeitos da radiação , Suíça , Glândula Tireoide/efeitos da radiação , Fatores de Tempo , Bexiga Urinária/efeitos da radiaçãoRESUMO
BACKGROUND: Osteonecrosis (ON) as a complication during treatment of acute lymphoblastic leukemia (ALL) has gained rising attention over the past decade. Corticosteroids, representing an essential element of antileukemic therapy, are known to induce ON, which in turn may cause significant morbidity. Due to spontaneous reporting of affected patients with ON, a group-wide evaluation was performed to determine incidence, risk factors, and morbidity for ON. PROCEDURE: Patients were identified via spontaneous reporting to the study center and via questionnaire, addressing all 64 participating centers. We retrospectively analyzed 1,951 patients below 18 years of age who were treated according to trial ALL-BFM 95 between 01.01.1996 and 30.06.2000. RESULTS: Thirty-one patients (14 male, 17 female) affected by ON were identified. The overall 5-year cumulative incidence for ON is 1.8%. The incidence for patients <10 years is 0.2%, whereas for patients >/=10 years it is 8.9% (P = 0.00) and 16.7% (P = 0.003) for patients >/=15 years. The majority (n = 20) showed ON in two or more joints, and the joints most commonly affected were knees (14 patients, 24 affected knees) and hips (11 patients, 20 affected joints). Thirteen out of 31 patients had to undergo surgery in the course of their disease. CONCLUSIONS: Symptomatic ON is a rare event in patients treated with BFM-type chemotherapy with an overall 5-year cumulative incidence of 1.8%. The age group >/=10 years, and particularly adolescents >/=15 years have a significantly higher risk of developing ON.
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Glucocorticoides/toxicidade , Osteonecrose/induzido quimicamente , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adolescente , Criança , Pré-Escolar , Dexametasona/toxicidade , Feminino , Articulação do Quadril , Humanos , Lactente , Articulação do Joelho , Masculino , Prednisona/toxicidade , Estudos Retrospectivos , Inquéritos e QuestionáriosRESUMO
The authors describe a young boy with juvenile myelomonocytic leukemia (JMML) who relapsed 45 days after HLA and killer immunoglobulin-like receptor (KIR) mismatched unrelated donor bone marrow transplant (MMUD-BMT) and subsequently developed life-threatening graft-versus-host disease (GvHD). Treatment with 6-mercaptopurine (6-MP) appeared to control severe GvHD and possibly prevented recurrence of leukemic relapse.
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Antimetabólitos Antineoplásicos/uso terapêutico , Doença Enxerto-Hospedeiro/tratamento farmacológico , Transplante de Células-Tronco Hematopoéticas , Histocompatibilidade , Leucemia Mielomonocítica Aguda/tratamento farmacológico , Mercaptopurina/uso terapêutico , Receptores Imunológicos/genética , Bussulfano/administração & dosagem , Ciclofosfamida/administração & dosagem , Efeito Enxerto vs Leucemia , Antígenos HLA-B/genética , Antígeno HLA-B52 , Antígenos HLA-C/genética , Humanos , Lactente , Leucemia Mielomonocítica Aguda/terapia , Masculino , Melfalan/administração & dosagem , Receptores KIR , Indução de Remissão , Prevenção Secundária , Condicionamento Pré-Transplante , Transplante HomólogoRESUMO
BACKGROUND: In 1998, a prospective multicenter pilot study of the 'Late Effects Surveillance System' (LESS) was started to investigate late effects of patients with Ewing, osteo- or soft-tissue sarcoma. PROCEDURE: Two hundred thirty patients were included in this pilot study. The patients were treated between 1/1/1998 and 6/30/1999 according to the sarcoma protocols COSS-96, CWS-96, and EICESS-92, the median cumulative doses of the focussed drugs were for cisplatin: 360 mg/m(2), for doxorubicin: 270 mg/m(2), and for ifosfamide: 24 g/m(2). The patients were investigated using an organ related standardized screening methodology. We report on toxicities in the first year after cessation of therapy-the beginning of the patient follow-up-and the feasibility of LESS. RESULTS: Cardiotoxicity: 16/129 (12%) patients treated with doxorubicin exhibited a reduced systolic heart function (fractional shortening (FS) <29%). Altogether three patients required cardiac drug therapy. Ototoxicity: In 5/73 (7%) patients treated with cisplatin a hearing deficit <4 kHz (>20 dB) was found. One patient needed a hearing aid. Nephrotoxicity: 2 of 214 (1%) patients treated with ifosfamide suffered from a tubulopathy, which required supplementation therapy. 10/50 (20%) showed a reduced fractional phosphate reabsorption. Incidence of hypomagnesemia was significantly increased in patients additionally treated with cisplatin. CONCLUSIONS: Some relevant impairments are noted in the first year after antineoplastic therapy. We expect to detect more major late sequelae in our prospective study during the increasing posttherapeutic interval. Our pilot study shows the feasibility of the methodology.
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Antineoplásicos/toxicidade , Vigilância da População , Sarcoma/complicações , Sarcoma/tratamento farmacológico , Adolescente , Adulto , Antineoplásicos/administração & dosagem , Criança , Pré-Escolar , Cisplatino/administração & dosagem , Cisplatino/toxicidade , Doxorrubicina/administração & dosagem , Doxorrubicina/toxicidade , Estudos de Viabilidade , Transtornos da Audição/induzido quimicamente , Humanos , Ifosfamida/administração & dosagem , Ifosfamida/toxicidade , Lactente , Nefropatias/induzido quimicamente , Magnésio/metabolismo , Fosfatos/metabolismo , Projetos Piloto , Disfunção Ventricular Esquerda/induzido quimicamenteRESUMO
PURPOSE: To date, the event free survival (EFS) after treatment of childhood acute lymphoblastic leukemia (ALL) attains 80%. The survivor group is growing steadily. Therefore, the primary purpose of our study is to define the neuropsychological function and to describe which central nervous system (CNS) functions are impaired following the German ALL-BFM and COALL protocols for CNS-negative patients. PATIENTS AND METHODS: In a cross-sectional multicenter study 121 subjects, long-term survivors of childhood ALL in first continuous complete remission were investigated. Seven years ago, the subjects were treated as standard or medium risk patients according to ALL-BFM 81, ALL-BFM 83, or COALL 82 protocols, receiving comparable treatments. According to different CNS-prophylaxes, two subgroups were compared in the study: the non-cranially irradiated MTX-group (methotrexate-group) (n = 38) and the cranially irradiated RT-group (radiotherapy-group) (with MTX i.th.) (n = 83). Intellectual and cognitive abilities of these groups were evaluated using standardized psychometric techniques. The Kaufman factors Verbal Comprehension, Perceptual Organisation and Freedom from Distractibility were calculated. Demographical and clinical data collected at the time of the diagnosis were compared between both groups. The different prognoses for patients within both groups were taken into account using a defined risk factor. Analysis of variance was conducted to relate intellectual performance to age, gender, and CNS-treatment. RESULTS: The RT-group exhibited a lower Full Scale IQ than the MTX-group (101.2 +/- 15.9 vs. 109.9 +/- 14.9, P = 0.031). Particularly for the Kaufman factor Freedom from Distractibility the RT-group showed the lower scores (96.9 +/- 14.1 vs. 105.5 +/- 12.6, P = 0.037). Significant interactions between gender and CNS prophylactic treatment were observed for Full Scale IQ (P = 0.008), Verbal IQ (P = 0.012), Performance IQ (P = 0.024), Verbal Comprehension (P = 0.004), and Perceptual Organisation (P = 0.032). CONCLUSIONS: Cranial irradiation in combination with MTX therapy was associated with deficits in attention, concentration, and the ability of sequencing and processing, measured by the Kaufman factor Freedom from Distractibility. Our results support the strategy of avoiding prophylactic CNS irradiation in low risk patients.
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Antimetabólitos Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Transtornos Cognitivos/induzido quimicamente , Irradiação Craniana/efeitos adversos , Transtornos da Memória/induzido quimicamente , Metotrexato/efeitos adversos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/radioterapia , Adolescente , Adulto , Antimetabólitos Antineoplásicos/uso terapêutico , Atenção , Neoplasias Encefálicas/prevenção & controle , Neoplasias Encefálicas/secundário , Sistema Nervoso Central/fisiologia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Testes de Inteligência , Masculino , Metotrexato/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Fatores de RiscoRESUMO
The translocation t(9;11)(p22;q23) is a recurring chromosomal abnormality in acute myeloid leukemia (AML) fusing two genes designated as MLL and AF9. Within MLL, almost all rearrangements cluster in an 8.3-kb restricted region and fuse 5' portions of MLL to a variety of heterologous genes in various 11q23 translocations. AF9 is one of the most common fusion partners of MLL. It spans more than 100 kb, and two breakpoint cluster regions (BCRs) have been identified in a telomeric region of intron 4 (BCR1) and within introns 7 and 8 (BCR2). We investigated 11 children's bone marrow or peripheral blood samples (3 AML, 5 t-AML, 2 ALL, 1 ALL relapse) and two cell lines (THP-1 and Mono-Mac-6) with cytogenetically diagnosed translocations t(9;11). By use of an optimized multiplex nested long-range PCR assay, a breakpoint-spanning DNA fragment from each sample was amplified and directly sequenced. In four patients and two cell lines, the AF9 breakpoints were located within BCR1 and in two patients within BCR2, respectively. However, in five patients the AF9 breakpoints were found outside the previously described BCRs within the centromeric region of intron 4 and even within intron 3 in one case. All five patients with a secondary AML, who had not received etoposides during treatment of the primary malignant disease, revealed almost identical MLL breakpoints very close to a breakage hot spot inducible by topoisomerase II inhibitors or apoptotic triggers in vitro. Sequence patterns around the breakpoints indicated involvement of a "damage-repair mechanism" in the development of t(9;11) similar to t(4;11) in infants' acute leukemia.