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Biomedical subjects

Robert J Arceci

Publications and source records attributed to Robert J Arceci.

At least 19 recordsLinked to original sources

Mitoxantrone and cytarabine induction, high-dose cytarabine, and etoposide intensification for pediatric patients with relapsed or refractory acute myeloid leukemia: Children's Cancer Group Study 2951.

PURPOSE: To evaluate the response rate, survival, and toxicity of mitoxantrone and cytarabine induction, high-dose cytarabine and etoposide intensification, and further consolidation/maintenance therapies, including bone marrow transplantation, in children with relapsed, refractory, or secondary acute myeloid leukemia (AML). To evaluate response to 2-chlorodeoxyadenosine (2-CDA) and etoposide (VP-16) in patients who did not respond to mitoxantrone and cytarabine. PATIENTS AND METHODS: Patients with relapsed/refractory AML (n = 101) and secondary AML (n = 13) were entered. RESULTS: Mitoxantrone and cytarabine induction achieved a remission rate of 76% for relapsed/refractory patients and 77% for patients with secondary AML, with a 3% induction mortality rate. Cytarabine and etoposide intensification exceeded the acceptable toxic death rate of 10%. The response rate of 2-CDA/VP-16 was 8%. Two-year overall survival was estimated at 24% and was better than historical control data. Patients with secondary AML had similar outcomes to relapsed or refractory patients. Initial remission longer than 1 year was the most important prognostic factor for patients with primary AML (2-year survival rate, 75%), whereas for patients with primary AML, with less than 12 months of initial remission, survival was 13% and was similar to that of refractory patients (6%). CONCLUSION: Mitoxantrone and cytarabine induction is effective with reasonable toxicity in patients with relapsed/refractory or secondary AML. The cytarabine and etoposide intensification regimen should be abandoned because of toxicity. Patients with relapsed AML with initial remissions longer than 1 year have a relatively good prognosis.

Adolescent↗

Activating mutations of RTK/ras signal transduction pathway in pediatric acute myeloid leukemia.

Activating mutations of receptor tyrosine kinases (RTKs) and their downstream affectors are common in acute myeloid leukemia (AML). We performed mutational analysis of FLT3, c-kit, c-fms, vascular endothelial growth factor (VEGF) receptors (Flt-1, KDR [kinase domain receptor]), and ras genes in a group of 91 pediatric patients with AML treated on Children's Cancer Group clinical trial CCG-2891. Forty-six percent of patients had activating mutations of FLT3 (24.5%), c-kit (3%), or ras (21%) genes. Mutation-positive patients had a higher median diagnostic white blood cell (WBC) count (71.5 vs 19.6 x 10(9)/L; P =.005) and lower complete remission rate (55% versus 76%; P =.046) than mutation-negative patients. The Kaplan-Meier estimate of overall survival (OS) for patients with and without an activating mutation was 34% versus 57%, respectively (P =.035). However, within this group, patients with FLT3/ALM (activation loop mutation) had good outcomes (OS, 86%). Exclusion of the FLT3/ALM from analysis decreased the OS for the remaining mutation-positive patients to 26% (P =.003). Ten of the 23 mutation-positive and 11 of the 34 mutation-negative patients received an allogeneic bone marrow transplant (BMT) in first complete remission (CR). In the mutation-positive group, the disease-free survival (DFS) for the allogeneic BMT recipients was 72% versus 23% for the 13 patients who received chemotherapy or autologous BMT (P =.01). DFS for the mutation-free patients with and without allogeneic BM transplantation was 55% and 40%, respectively (P =.38). Activating mutations in the RTK/ras signaling pathway are common in pediatric AML, and their presence may identify a population at higher risk of poor outcome who may benefit from allogeneic BM transplantation.

Adolescent↗

Mutagenesis of GATA1 is an initiating event in Down syndrome leukemogenesis.

As many as 10% of infants with Down syndrome (DS) present with transient myeloproliferative disorder (TMD) at or shortly after birth. TMD is characterized by an abundance of blasts within the peripheral blood and liver, and notably undergoes spontaneous remission in the majority of cases. TMD may be a precursor to acute megakaryoblastic leukemia (AMKL), with an estimated 30% of TMD patients developing AMKL within 3 years. We recently reported that mutations in the transcription factor GATA1 are associated with DS-AMKL. To determine whether the acquisition of GATA1 mutations is a late event restricted to acute leukemia, we analyzed GATA1 in DNA from TMD patients. Here we report that GATA1 is mutated in the TMD blasts from every infant examined. These results demonstrate that GATA1 is likely to play a critical role in the etiology of TMD, and mutagenesis of GATA1 represents a very early event in DS myeloid leukemogenesis.

Cell Transformation, Neoplastic↗

Update in childhood acute myeloid leukemia: recent developments in the molecular basis of disease and novel therapies.

Childhood acute myeloid leukemia is a heterogeneous group of disorders that remains challenging to treat. There are multiple common genetic alterations in childhood acute myeloid leukemia. These include chromosomal translocations affecting RUNX1-CBFbeta, RARalpha, and MLL. There are known activating mutations in the genes for the receptor tyrosine kinases FLT3, KIT, and FMS. As these abnormalities are better understood, they are providing important insights into the pathogenesis of disease as well as information about prognosis. Although intensive chemotherapy remains the mainstay of acute myeloid leukemia therapy, long-term cure rates with chemotherapy alone remain approximately 50%, creating an urgent need for better therapies. Multiple avenues are being explored in the design of new treatments for pediatric acute myeloid leukemia. Targeted therapies include targeted antibody therapy; inhibitors of FLT3, KIT, and farnesyltransferase; diphtheria toxin conjugated to the granulocyte-macrophage colony-stimulating factor; and antisense oligonucleotides. Another area of interest is chromatin remodeling and differentiation therapy, including agents such as all- retinoic acid, arsenic trioxide, and inhibitors of DNA methylation and histone deacetylation. There are also ongoing trials of antiangiogenesis agents. Another avenue for novel therapies is immunotherapy with agents such as interleukin-2 and tumor vaccines. This article reviews recent advances in understanding of the molecular basis for childhood acute myeloid leukemia and the design of novel therapies for the treatment of childhood acute myeloid leukemia.

Acute Disease↗

Immunophenotypic evidence of leukemia after induction therapy predicts relapse: results from a prospective Children's Cancer Group study of 252 patients with acute myeloid leukemia.

Approximately 40% of children with acute myeloid leukemia (AML) who respond to initial therapy subsequently relapse. Multidimensional flow cytometry employing a standardized panel of monoclonal antibodies enables the detection of small numbers of occult leukemic cells that persist during therapy using technology adaptable by most clinical laboratories. We performed a prospective, blinded evaluation of bone marrow specimens obtained from 252 pediatric patients with de novo AML to determine whether detection of occult leukemia defined as more than or equal to 0.5% blasts with aberrant surface antigen expression as determined by flow cytometry was predictive of subsequent relapse. Occult leukemia was detected in 41 (16%) of the 252 patients who responded to initial induction therapy. In time-dependent multivariate analyses that controlled for allogeneic marrow transplantation, variable intervals between sample submission, age, sex, white blood cell count at diagnosis, presence of splenomegaly or hepatomegaly, and presence of more than 15% blasts in the marrow after the first course of induction, patients harboring occult leukemia were 4.8 times more likely to relapse (95% confidence interval [CI] = 2.8 to 8.4, P <.0001) and 3.1 times more likely to die (95% CI; 1.9 to 5.1, P <.0001) than those lacking leukemia detectable by flow cytometry. In this analysis, flow cytometric evidence of leukemia after the initiation of therapy emerged as the most powerful independent prognostic factor associated with poor outcome. Among patients in whom a marrow sample was available for analysis at the end of consolidation therapy, overall survival at 3 years was 41% versus 69% for patients with and without occult leukemia, respectively (P =.0058).

Acute Disease↗

Emerging cancer-targeted therapies.

There is reason to believe that the unfolding revolution in molecular biology and translational research will allow selective targeting of tumor cells, and radically change the way general practitioners and pediatric oncologists treat and follow children with cancer. This article highlights some of the most promising approaches being tested in the field. By learning about the underlying biology, the remaining hurdles, the projected timeline, and the possible impact of new therapies on the practice of pediatric oncology, health care professionals and patients should be better prepared for the future of pediatric oncology.

Cancer Vaccines↗

Progress and controversies in the treatment of pediatric acute myelogenous leukemia.

The outcome for children and adolescents with acute myelogenous leukemia (AML) has substantially improved during the past several decades, such that nearly 50% of these patients can be cured. A significant part of this improvement has occurred over the past 10 years, during which time, dose intensification has played a much greater role in therapeutic strategies. Although dose intensification increased the cure rate for pediatric patients with AML, there has also been increased treatment-related morbidity and mortality. Further, despite such toxicity, the primary cause of death is still leukemia. This article outlines some of the different strategies leading to our current treatments and presents several questions and controversies. These questions lead to what future therapeutic options and approaches will be pursued.

Antineoplastic Combined Chemotherapy Protocols↗

Atypical cellular disorders.

Atypical cellular disorders are commonly considered part of the gray zone linking oncology to hematology and immunology. Although these disorders are relatively uncommon, they often represent significant clinical problems, provide an opportunity to understand basic disease mechanisms, and serve as model systems for the development of novel targeted therapies. This chapter focuses on such disorders. In Section I, Dr. Arceci discusses the pathogenesis of Langerhans cell histiocytosis (LCH) in terms of the hypothesis that this disorder represents an atypical myeloproliferative syndrome. The clinical manifestations and treatment of LCH in children and adults is discussed along with possible future therapeutic approaches based upon biological considerations. In Section II, Dr. Longley considers the molecular changes in the c-Kit receptor that form the basis of mastocytosis. Based on the location and function of c-Kit mutations, he develops a paradigm for the development of specific, targeted therapies. In Section III, Dr. Emanuel provides a review of the "mixed myeloproliferative and myelodysplastic disorders," including novel therapeutic approaches based on aberrant pathogenetic mechanisms. Taken together, these chapters should provide an overview of the biological basis for these disorders, their clinical manifestations, and new therapeutic approaches.

Adult↗

What is the optimal therapy for childhood AML?

The use of intensive therapy overa brief period of time has produced dramatic improvements in outcome for pediatric patients with acute myelogenous leukemia (AML), as has been demonstrated in studies by the major cooperative groups in the United States and Europe. Still, despite high-intensity chemotherapy and bone marrow transplantation, only about half of the children diagnosed with AML are cured. Future improvements are unlikely to come from further increases in chemotherapy intensity. Alternative approaches, such as risk-directed therapy based on different prognostic criteria; differentiation therapy with all-trans-retinoic acid (ATRA, Vesanoid), arsenic trioxide (Trisenox), or azacytidine; and immunotherapy with monoclonal antibodies, tumor vaccines, or cytokines may lead to further advances.

Antineoplastic Agents↗