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Biomedical subjects

John M Bennett

Publications and source records attributed to John M Bennett.

36 records · Page 2Linked to original sources
PubMed2004

A 2-year-old with atypical CML with a t(5;12)(q33;p13) treated successfully with imatinib mesylate.

Atypical chronic myelogenous leukemia (aCML) is a myelodysplastic/myeloproliferative disorder that usually occurs in older adults. Here we report a pediatric patient with aCML and a t(5;12)(q33;p13) with a corresponding fusion gene ETV6-PDGFRB. Because the PDGFRB tyrosine kinase is one of the known targets of tyrosine kinase inhibitors, this patient achieved cytogenetic and molecular remission with treatment with imatinib mesylate (formerly STI571; now Gleevec in the United States and Glivec in Europe). This case illustrates one of many myelodysplastic/myeloproliferative disorders that can be treated with this particular tyrosine kinase inhibitor.

Benzamides↗
PubMed2003

Revised recommendations of the International Working Group for Diagnosis, Standardization of Response Criteria, Treatment Outcomes, and Reporting Standards for Therapeutic Trials in Acute Myeloid Leukemia.

An International Working Group met to revise the diagnostic and response criteria for acute myelogenous leukemia originally published in 1990, as well as to provide definitions of outcomes and reporting standards to improve interpretability of data and comparisons among trials. Since the original publication, there have been major advances in our understanding of the biology and molecular genetics of acute leukemia that are clinically relevant and warrant incorporation into response definitions. Differences from the 1990 recommendations included a category of leukemia-free state, new criteria for complete remission, including cytogenetic and molecular remissions and remission duration. Storage of viable blasts for correlative studies is important for future progress in the therapy of these disorders.

Clinical Trials as Topic↗
PubMed2003

A phase 3 study of three induction regimens and of priming with GM-CSF in older adults with acute myeloid leukemia: a trial by the Eastern Cooperative Oncology Group.

The optimal induction for older adults with acute myeloid leukemia (AML) is unknown. Several anthracyclines have been proposed, but the data remain equivocal. Additionally, few prospective trials of priming with hematopoietic growth factors to cycle leukemia cells prior to induction chemotherapy have been conducted. Three hundred and sixty-two older adults with previously untreated AML were randomized to either daunorubicin, idarubicin or mitoxantrone with a standard dose of cytarabine as induction therapy. In addition, 245 patients were also randomized to receive granulocyte-macrophage colony-stimulating factor (GM-CSF) or placebo beginning 2 days prior to induction chemotherapy and continuing until marrow aplasia. No difference was observed in the disease-free overall survival or in toxicity among patients receiving any of the 3 induction regimens or among those receiving growth factor or placebo for priming. However, the complete remission rate for the first 113 analyzable patients, who did not participate in the priming study and started induction therapy 3 to 5 days earlier than those who did, was significantly higher (50% versus 38%; P =.03). None of the anthracyclines is associated with improved outcome in older adults. Priming with hematopoietic growth factor did not improve response when compared with placebo. Furthermore, delaying induction therapy in older adults may lead to a lower complete remission rate.

Aged↗
PubMed2003

Phase II study of alpha2 interferon in the treatment of the chronic myeloproliferative disorders (E5487): a trial of the Eastern Cooperative Oncology Group.

BACKGROUND: In vitro and clinical data suggest a therapeutic role for alpha2 interferon (IFN) in the treatment of the chronic myeloproliferative disorders. Accordingly, a multiinstitutional, Phase II trial of IFN in patients with agnogenic myeloid metaplasia (AMM), essential thrombocythemia (ET), and polycythemia rubra vera (PRV) in the spent phase was initiated. The objectives of this study were 1) to investigate the response rates that may be achieved with IFN in the treatment of patients with these disorders, 2) to estimate the durability of the responses, and 3) to assess the toxicities of IFN in these populations. METHODS: Enrollment was limited to patients with AMM, ET, or PRV who already had developed 1) anemia or transfusion dependency, 2) thrombocytosis uncontrolled by standard therapy, 3) hemostatic complications, or 4) symptomatic splenomegaly. Initially, patients were started on IFN at a dose of 5 MU/m(2) per day as a subcutaneous injection. After the first 16 patients had been treated, the starting dose of IFN was reduced to 2 MU/m(2) per day because of unexpected toxicities. RESULTS: IFN demonstrated different levels of efficacy and toxicity in each of the three diseases studied. The overall response rates achieved among the evaluable patients in each category were as follows: ET, 88.2% (n = 17 patients; 1 complete response and 14 partial responses); PRV, 41.7% (n = 12 patients; 1 complete response and 4 partial responses); and AMM, 3.2% (n = 31 patients; 0 complete responses and 1 partial response). Thrombocytosis and leukocytosis were controlled in nearly all patients, with reversal of splenomegaly and resorption of myelofibrosis achieved in fewer patients. The toxicities attributed to IFN differed notably among the three disease groups: patients who had AMM suffered systemic and neurologic toxicities more frequently than patients who had PRV or ET; whereas patients who had ET experienced a greater than expected incidence of hepatic abnormalities, most typically transient elevations of serum amino acid transaminase levels. CONCLUSIONS: The current study demonstrated the safety and efficacy of IFN in patients with ET, PRV, and AMM. Objective responses and/or disease stabilization were obtained in patients with all three disease entities, including the reversal of splenomegaly and resorption of myelofibrosis in some patients.

Adult↗
PubMed2003

Treatment-related myelodysplasia and acute leukemia in non-Hodgkin's lymphoma patients.

PURPOSE: Standard therapies for non-Hodgkin's lymphoma (NHL) are associated with an increased risk of developing treatment-related myelodysplastic syndrome or acute myelogenous leukemia (tMDS/AML). However, there is considerable debate over the incidence or risk of tMDS/AML in NHL patients treated with any particular modality and the factors that contribute to malignant transformation. DESIGN: Conclusions were based on thorough analysis of data reported in the peer-reviewed literature and careful examination of the statistical methodology and methods for identifying cases of tMDS/AML. Unless noted, data are reported only for NHL patients, excluding Hodgkin's disease patients. RESULTS: Despite differences in methods used to identify cases and to estimate the cumulative incidence over time (actuarial v cumulative calculations), up to 10% of NHL patients treated with either conventional-dose chemotherapy or high-dose therapy and autologous stem-cell transplantation may develop tMDS/AML within 10 years of primary therapy. Kaplan-Meier estimates of the actuarial incidence, which are based on censoring of patients who died without developing tMDS/AML, can lead to artificially high estimates with large confidence intervals at later time points. Although there is much debate about the cause(s) of tMDS/AML, there is compelling evidence that alkylating agents, certain other leukemogenic agents, and total-body irradiation (TBI) cause chromosomal damage that can lead to tMDS/AML. CONCLUSION: Limiting exposure to alkylating agents and eliminating TBI from transplantation conditioning regimens may reduce the relative risk of tMDS/AML.

Acute Disease↗
PubMed2003

Aggressive systemic mastocytosis and related mast cell disorders: current treatment options and proposed response criteria.

Aggressive systemic mastocytosis (ASM) is a clonal mast cell disease characterized by progressive growth of neoplastic cells in diverse organs leading to organopathy. The organ-systems most frequently affected are the bone marrow, skeletal system, liver, spleen, and the gastrointestinal tract. Respective clinical findings (so called C-Findings) include cytopenias, osteolysis (or osteoporosis) with pathologic fractures, hepatosplenomegaly with impaired liver function and ascites, and malabsorption. During the past decade several treatment strategies for ASM have been proposed. One promising approach may be combination treatment with interferon-alpha (IFN-alpha) and glucocorticoids. This concept has been based on the notion that systemic mastocytosis involves multilineage hematopoietic progenitors indicating a relationship with myeloproliferative disorders. However, relatively little is known about the quality of responses to IFN-alpha in ASM and the actual response rates. This may be due in part to the fact that disease criteria for ASM have only recently been established, and no response criteria are available. In the current article, we propose surrogate markers and treatment response criteria for patients with ASM. In addition, we have applied these criteria retrospectively to ASM patients described in the available literature. In these analyses, the calculated rate of major response (=complete resolution of C-Findings) in patients treated with IFN-alpha (with or without additional glucocorticoids) amounts to approximately 21%. This confirms clinical activity in some patients for this drug-combination, but also points to the need to search for more effective strategies in the treatment of patients with aggressive mast cell disorders.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2003

Burkitt's leukemia with precursor B-cell immunophenotype and atypical morphology (atypical Burkitt's leukemia/lymphoma): case report and review of literature.

A 45-year-old male presented with fever, night sweats, splenomegaly, high LDH, high uric acid, and high blast count with atypical L3 morphology. Flow cytometry showed neoplastic clone consistent with pre B-cell immunophenotype, on the basis of lack of cytoplasmic immunoglobulins, surface immunoglobulins, and light chain immunoglobulins. Cytogenetic analysis revealed t(8;14)(q24; q32), the characteristic translocation of Burkitt's leukemia. A few similar case reports of Burkitt's leukemia with precursor B-cell immunophenotype have been described primarily in pediatric literature and usually with typical L3 morphology. This case recognizes this subset in adult ALL and emphasizes the need for comprehensive diagnostic analysis.

Adolescent↗
PubMed2003

Comparison of interphase FISH and metaphase cytogenetics to study myelodysplastic syndrome: an Eastern Cooperative Oncology Group (ECOG) study.

Cytogenetic analysis can be important in determining the prognosis and diagnosis of a number of hematological disorders, including myelodysplastic syndromes (MDS). Here, we compared metaphase chromosomal analyses on bone marrow aspirates from MDS patients with interphase fluorescence in situ hybridization (FISH) using probes specific for chromosomes nos. 5, 7, 8, 11, 13 and 20. Forty-three patients enrolled in ECOG protocol E1996 for low risk MDS and five patients enrolled in ECOG protocol E3996 for high risk MDS were studied by both metaphase chromosomal analysis and interphase FISH. Excluding those with a clonal loss of the Y chromosome, an abnormal clone was detected by cytogenetic analysis in 18 of 48 samples (37.5%). In comparison, our FISH panel detected an abnormal clone in 17 of 48 samples (35.4%). Twenty-nine of 30 samples with apparently normal karyotypes, including those with a missing Y chromosome, were also normal by our FISH panel. One patient had an occult deletion of chromosome 11 that was detected by FISH. These results indicate that around 60% of patients with MDS do not have abnormalities that are detectable by either chromosomal or FISH studies. In addition, it appears that interphase FISH studies are nearly as sensitive as cytogenetic analyses and can be a useful tool in studying bone marrow aspirates where cytogenetic analysis is not possible.

Antineoplastic Agents↗
PubMed2003

The myelodysplastic/myeloproliferative disorders: the interface.

Most patients with myelodysplastic syndromes can be identified easily and separated from patients who have myeloproliferative disorders. A few have overlapping features, however, with evidence of morphologic dysplasia and a proliferative advantage of one or more of the myeloid differentiating cell lines. For practical purposes and therapeutic considerations, chronic myelomonocytic leukemia is viewed now as a composite disorder along with atypical chronic myeloid leukemia and juvenile myelomonocytic leukemia.

Genes, ras↗
PubMed2003

A randomized trial of induction therapy (daunorubicin, vincristine, prednisone versus daunorubicin, vincristine, prednisone, cytarabine and 6-thioguanine) in adult acute lymphoblastic leukemia with long-term follow-up: an Eastern Cooperative Oncology Group Study (E3486).

In this study of previously untreated adult acute lymphocytic leukemia (ALL) performed by the Eastern Cooperative Oncology Group, patients were randomized to induction therapy with either DVP (daunorubicin 45 mg/m2 daily, days 1, 2 and 3; prednisone 60 mg/m2 daily orally days 1-35; and vincristine 2 mg intravenously on days 1, 8, 15 and 22) or DATVP (daunorubicin 60 mg/m2 daily, days 1, 2 and 3; cytarabine 25 mg/m2 intravenous bolus followed by 200 mg/m2 daily as a continuous infusion on days 1-5; 6-thioguanine 100 mg/m2 orally every 12 h on days 1-5; vincristine 2 mg intravenously on days 1 and 8; and prednisone 60 mg/m2/day orally, days 1-7. Complete responders to both regimens received the same post-remission therapy, which consisted of a single course of cytarabine 3 gm/m2 infused over 1 h every 12 h for 12 doses. One month later those patients still in remission received six cycles of consolidation therapy with MACHO (cyclophosphamide 650 mg/m2, doxorubicin 40 mg/m2 vincristine 2mg all intravenously on day 1 with prednisone 100 mg/m2 orally daily on days 1-5. Methotrexate 200 mg/m2 intravenously and L-asparaginase 6000 U/m2 were given on day 22 and each course was given every 5 weeks. A single dose of intrathecal methotrexate was also given with each MACHO course. There were 276 evaluable patients randomized in this study. Complete response rates were 71% for DVP and 58% for DATVP. Median durations of complete response were 5.5 and 6.8 months, respectively. Median survival of all randomized patients was 14.4 months in each group. DATVP was more toxic than DVP. Intensification of treatment for adults with ALL may not improve outcome. Progress in the treatment of adults with ALL will require the identification of new agents for this neoplasm.

Adolescent↗
PubMed2003

The myelodysplastic syndromes: classification and prognosis.

Myelodysplastic syndrome is a neoplastic clonal stem cell disorder characterized clinically by bone marrow failure and a tendency to progress to acute myelogenous leukemia. Dysplasia is the pathologic hallmark. The French-American-British classification served as the gold standard for more than two decades. Under the auspice of the World Health Organization, more than 100 hematopathologists in a 3-year cumulative effort issued the new World Health Organization classification, which recognizes multilineage dysplasia. Refractory anemia with excess blasts is divided into two groups. Chronic myelomonocytic leukemia is reclassified under a separate category. Refractory anemia with excess blasts in the transformation group was omitted. Finally, 5q-syndrome is a new subgroup. In addition to the pathologic classification, various prognostic predictors were formatted into scoring systems. Bone marrow blast percentage, cytopenias, and cytogenetics are the backbone for those prognostic models. The International Prognostic Scoring System is a product of pooled data from previous scoring systems and a useful tool to predict survival and acute myelogenous leukemia evolution. This paper discusses the classification and prognosis of myelodysplastic syndromes and their evolution.

Classification↗
PubMed2002

The myelodysplastic syndromes: morphology, risk assessment, and clinical management (2002).

The Myelodysplastic Syndromes (MDS) represent a group of potentially acute myeloid leukemic disorders. There exists a delicate balance between increased apoptosis and proliferation of the leukemic hematopoietic stem cell that permits many patients to survive for years. When the balance shifts towards proliferation AML develops with a poor outcome for most but not all patients. I will review the latest proposals from the W.H.O. in classification, including pediatric MDS, prognostic factors and response criteria. Then I will present a strategy for the management of low risk patients with supportive care or low intensity treatment (cytokines, Immune modulation, anti-VEGF agents) and finally chemotherapy and intensive therapy with auto and allo BMT.

Cell Transformation, Neoplastic↗
PubMed2002

Chronic myelomonocytic leukemia.

Chronic myelomonocytic leukemia (CMML) has dysplastic and proliferative features. The median age of patients with CMML is 70 years; the median survival is approximately 2 years. Various chemotherapy regimens have been used with only modest success. When the proliferative phase prevails, hydroxyurea is the treatment of choice. For younger patients with high-risk CMML, an allogeneic bone marrow transplantation should be considered. If a donor cannot be identified, then combination acute myeloid leukemia-type therapy followed by an autologous stem cell or marrow transplant should be offered. Clinical trials should be considered if available because the overall results of therapeutic interventions are far from optimal.

Antineoplastic Agents↗