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Biomedical subjects

E H Estey

Publications and source records attributed to E H Estey.

At least 55 records · Page 3Linked to original sources
PubMed1997

1,25-Dihydroxyvitamin D3 and its analogues inhibit acute myelogenous leukemia progenitor proliferation by suppressing interleukin-1beta production.

We hypothesized that 1,25-dihydroxyvitamin D3 (1,25D3) and its analogues may inhibit acute myelogenous leukemia (AML) proliferation by interrupting IL-1beta-mediated growth-stimulatory signals. The incubation of the IL-1beta- responsive AML cell line OCIM2 with 10 nM 1,25D3 reduced growth 80% in liquid culture, and a 100-1000-fold lower concentration of 20-epi analogues (MC1288 and MC1301) was sufficient to achieve similar growth inhibition. The growth inhibition was associated with a rapid but transient downregulation of IL-1beta and IL-1beta-converting enzyme (ICE) mRNAs in 1,25D3- and 20-epi analogue- treated cells, and the 20-epi analogue was more effective than 1,25D3 in repressing ICE expression. An examination of long-term changes in the levels of mature IL-1beta and its precursor revealed that 24-h incubation of OCIM2 with either 1,25D3 or its 20-epi analogues abolished the production of mature IL-1beta. The effect of 1,25D3 and its analogues on growth of fresh bone marrow cells from seven AML patients was tested by a clonogenic assay. Growth inhibition of 60% was reached in only one of seven 1,25D3-treated samples, but all seven samples were inhibited 60-90% by the 20-epi analogue MC1301. Growth inhibition by 1,25D3 and the analogue was reversible by addition of IL-1beta. These results suggest that 1,25D3 and its 20-epi analogues interrupt IL-1beta autocrine growth regulation by inhibiting IL-1beta production and processing but not the response to IL-1beta.

Antineoplastic Agents↗
PubMed1996

New statistical strategy for monitoring safety and efficacy in single-arm clinical trials.

PURPOSE: Efficacy and toxicity are both important outcomes in cancer clinical trials. Nonetheless, most statistical designs for phase II trials only provide rules for evaluating treatment efficacy, and moreover only allow early stopping after fixed cohorts of patients have been treated. We illustrate a new statistical design strategy for monitoring both adverse and efficacy outcomes on a patient-by-patient basis in phase II and other single-arm clinical trials. DESIGN: The new strategy is used to design a phase II trial of the experimental regimen idarubicin plus cytarabine (ara-C) plus cyclosporine for treatment of patients with intermediate-prognosis acute myelogenous leukemia (AML). The design requires a maximum of 56 patients and provides continuous monitoring boundaries to terminate the trial if the toxicity rate is unacceptably high or the complete remission (CR) rate is unacceptably low compared with the rates of these events with the standard regimen of anthracycline plus ara-C. RESULTS: The design has an 88% to 91% probability of stopping the trial early with a median of 15 to 18 patients if the toxicity rate of the experimental regimen is .05 to .10 above that of the standard and there is no improvement in the CR rate. If there is a .15 improvement in the CR rate and the toxicity rate is no more than .05 above that of the standard, then there is at least an 83% probability that the trial will run to completion. CONCLUSION: The proposed monitoring strategy provides a flexible, practical means to continuously monitor both safety and efficacy in single-arm cancer clinical trials. The design strategy can be implemented easily using a freely available menu-driven computer program, and provides a scientifically sound alternative to the use of ad hoc safety monitoring rules.

Anthracyclines↗
PubMed1996

Amsacrine and continuous-infusion high-dose cytosine arabinoside as induction therapy for patients with newly-diagnosed acute myelogenous leukemia.

The overall cure rate of adults with newly-diagnosed acute myelogenous leukemia (AML) treated with continuous infusion high-dose cytarabine (CIHDAC) is comparable to that with standard-dose ara-C plus anthracycline or amsacrine (AMSA). We tested whether the addition of AMSA to CIH-DAC improves the outcome of adults with untreated AML. 75 patients with untreated AML were treated with AMSA (75 mg/m2/day x 4) plus CIHDAC (1.5 g/m2/day x 4) for induction and, if in complete remission (CR), early and late intensification. Results were compared to those in 129 patients treated on a previous study with CIHDAC alone. The principal comparison in both groups was between those 117 patients (AMSA/CIHDAC n = 52, CIHDAC n = 65) who met the initial eligibility criteria for the AMSA/CIHDAC study (risk of early mortality < or = 1) and who were treated at a time when relatively few eligible patients were excluded (19% in the AMSA/CIHDAC group, 34% in the CIHDAC group). There was no difference between regimens in CR rate, remission duration, or survival in this cohort. When attention was turned to all 204 patients, outcome was superior with AMSA/CIHDAC very largely as a result of outcome in patients with APL. Aside from these patients, addition of amsacrine to CIHDAC did not appear to be productive.

Acute Disease↗
PubMed1996

Thrombosis in patients with acute promyelocytic leukemia treated with and without all-trans retinoic acid.

Laboratory evidence of disseminated intravascular coagulation (DIC) and/or fibrinolysis is present in the majority of patients with acute promyelocytic leukemia (APL). Historically, early hemorrhagic death (EHD) occurred in 10% to 30% of patients treated with chemotherapy. All-trans retinoic acid (ATRA), a differentiating agent, has a CR rate above 80% in patients, with ATRA-associated leukocytosis. We studied thrombotic events in this population and compared it to patients treated with chemotherapy alone. The results of studies using ATRA in patients with APL were reviewed. Patients received ATRA 45-50 mg/m(2) orally in two divided doses daily until complete remission. In newly diagnosed patients, Idarubicin 12 mg/m(2)/day was given intravenously for 4 to 5 days beginning on the fifth day of ATRA therapy or when the white blood cell count (WBC) was over 10x 10(3)/mu l. Thrombotic complications were noted in 3 of 31 patients during induction. Two died from thrombotic events during therapy with multiple thromboses documented at autopsy. ATRA syndrome was suspected in 2 of the patients with thromboses and only 1 of the patients without thrombosis. In previous studies, 1 of 25 APL patients treated with chemotherapy alone had thrombotic events during therapy. In conclusion, treatment of APL with ATRA may decrease the incidence of hemorrhagic complications, but does not eliminate thrombosis. While thrombotic events were not significantly increased in patients treated with ATRA, they were more common in patients suspected of having ATRA syndrome.

Adult↗
PubMed1996

Chemotherapy versus transplants for acute myelogenous leukemia in second remission.

The best therapy for persons with acute myelogenous leukemia (AML) in 2nd remission is unknown. Bone marrow transplants from an HLA-identical sibling are reported to be better than chemotherapy but this is controversial. The objective of the study was to compare 3-year leukemia-free survival (LFS) in comparable subjects receiving chemotherapy or a transplant. 485 persons with AML in 2nd remission were studied. The chemotherapy cohort included 244 persons treated on trials of the British Medical Research Council, Eastern Cooperative Oncology Group and MD Anderson Hospital. The transplant cohort included 257 persons transplanted worldwide and reported to the international Bone Marrow Transplant Registry (16 were also chemotherapy subjects.) Subjects were selected for comparable age and year of treatment. Preliminary analyses identified two factors correlated with LFS: age < or = or > 30 years and 1st remission duration < or = or > 1 year; subsequent analyses were partitioned accordingly. Three-year probabilities of treatment-related mortality with chemotherapy and transplants were 7% (95% confidence interval, 3-15%) vs 56% (49-63%). Three-year leukemia relapse probabilities were 81% (74-86%) vs 41% (33-49%). Three-year probabilities of LFS were 17% (12-23%) vs 26 (20-32%). Cohort analysis showed significantly higher LFS with transplants vs chemotherapy in persons < or = 30 years and 1st remissions > 1 year (41% (29-53%) vs 17% (7-32%); P = 0.017) and those in > 30 years with 1st remissions < or = 1 year (18% (9-29%) vs 7% (2-16%); P = 0.046). Others had comparable LFS with both treatments. These data indicate better LFS with HLA-identical sibling transplants than chemotherapy in some persons with AML in 2nd remission.

Adolescent↗
PubMed1996

Secondary acute promyelocytic leukemia. Characteristics and prognosis of 14 patients from a single institution.

The aims of this study were to analyze the characteristics and outcome of patients with secondary acute promyelocytic leukemia (APL) and compare them to those with primary APL. One hundred and thirteen patients referred to our service with a diagnosis of APL were reviewed. Fourteen were classified as secondary APL. Nine were induced with chemotherapy, and five with all-trans retinoic acid plus chemotherapy. Pretreatment characteristics, response to therapy and outcome of primary vs secondary APL were compared by standard statistical methods. Secondary APL constituted 12% of all APL cases. Patients with secondary APL were significantly older (median age 56 vs 36 years; P < 0.01) and had a lower incidence of hypofibrinogenemia (P < 0.01) than those with primary APL. The complete response (CR) rates were similar with secondary vs primary APL (CR rates 79 vs 69%), as were CR duration and survival. The CR rates at 5 years were 57 and 45%, respectively(P not significant), and the survival rates 37 and 35%, respectively (P not significant). The incidence of secondary APL within APL disease (12%) was similar to the incidence of secondary acute myeloid leukemia (AML) in karyotypes not known to be therapy-related (diploid, t(8;21), inversion 16: incidences 9 to 12%), but was significantly lower than in karyotypes known to be therapy-related (chromosome 5 or 7 abnormalities, 11q; incidences 30 and 33%). We conclude that secondary APL has general characteristics and outcome similar to primary APL. it is more likely a second primary rather than therapy-related AML, and should be treated in a manner similar to primary APL.

Adult↗
PubMed1996

Causes of initial remission induction failure in patients with acute myeloid leukemia and myelodysplastic syndromes.

We analyzed 144 of 475 previously untreated patients with acute myeloid leukemia (AML, n = 87) and 'high-risk' myelodysplastic syndromes (MDS, n = 57) who failed to achieve a complete remission with fludarabine- and high-dose cytarabine-containing regimens between 1991 and 1994. The AML and MDS groups were comparable with regard to age, major prognostic indicators, supportive care received, type of antileukemia response and causes of death and were considered together. The causes of death of 118 evaluable patients were compared to a series of 123 AML initial remission induction failures previously reported from our institution. The induction failure rate was significantly lower (30 vs 43% P <0.001). We found a significant decrease in fatal infections (autopsied patients, P = 0.001) and a reduction in bacterial (autopsied and non-autopsied patients, P <0.005) but not fungal (non-autopsied patients, P = 0.93; autopsied patients P = 0.15) infections as causes of induction death. Pulmonary hemorrhage was twice as common in the present report (P < 0.005, with pulmonary hemorrhage almost three times as common as fatal cerebral hemorrhage. A comparison restricted to the AML patients in the present study yielded similar results. We conclude that the mortality profile in AML remission induction has undergone substantial changes at our institution since our last report, probably as a consequence of the introduction of new chemotherapy regimens and supportive care modalities.

Acute Disease↗
PubMed1996

New chemotherapeutic agents in acute myeloid leukemia.

Only two classes of chemotherapeutic agents have shown activity in acute myeloid leukemia (AML): ara-C and topoisomerase II reactive agents. Frontline combinations of these agents produce complete response (CR) rates of 70% and long-term event free survival rates of 25%. New agents with different mechanisms of action are being explored. Nucleoside analogs such as chlorodeoxyadenosine (2-CdA) or fludarabine have shown single-agent efficacy and may be synergistic with ara-C. Combination therapy with ara-C and nucleoside analogs have shown promising results both as salvage therapy and in newly diagnosed patients. Combinations of topotecan with ara-C, VP16, and anthracyclines are being pursued, as is testing of other Topo-I inhibitors. Hypomethylating agents (5-azacytidine, decitabine) are showing activity in AML, producing CR rates of 5% to 30% as AML salvage therapy as a single agent, and 40%-60% in combinations. Decitabine may be synergistic with topo I inhibitors, biologic agents, and differentiating agents. Homoharringtonine has modest anti-AML activity, with CR rates of 10% to 30% as salvage therapy. Other classes of agents worthy of continuing investigation are platinum analogs and agents with novel mechanisms of action such as tallimustine.

Acute Disease↗
PubMed1996

Factors predicting complete remission and subsequent disease-free survival after a second course of induction therapy in patients with acute myelogenous leukemia resistant to the first.

Patients with newly diagnosed acute myelogenous leukemia (AML) with persistent leukemia after their first course (CO1) of induction chemotherapy are generally given a second similar course, although their outcome is known to be worse than CO1 responders even when a complete remission (CR) is achieved. To identify specific patients who should or should not receive a second induction course identical to the first we analyzed outcome in 370 patients with persistent AML after CO1 who received a second identical course. One hundred and forty-two (38%) achieved CR on this course; median subsequent disease-free survival (DFS) in these 142 was 29 weeks and 10% were alive in CR at 5 years. The 5-year DFS of CO2 responders was significantly lower than that of CO1 responders (10 vs 24%, P < 0.001). Logistic regression identified pretreatment cytogenetic abnormalities (except inv 16, t(8;21), or t(15;17)), presence of an antecedent hematologic disorder or secondary AML as each having unfavorable prognostic import similar to the case in untreated patients. Treatment with "high-dose' rather than standard-dose cytarabine increased the probability of 2nd course CR. The occurrence of pneumonia, sepsis, or major hemorrhage were prognostically unfavorable, primarily in the high-dose cytarabine group, and, once in CR, DFS was shorter in this group. Equations predicting probability of 2nd course CR were derived. If validated prospectively these could be used to assign patients to either receive a second course of initial induction therapy or to change to salvage or investigational therapy after the first course. Alternatively, they could be used to stratify patients entering a prospective randomized trial comparing these two strategies.

Adult↗
PubMed1996

Pneumonia during remission induction chemotherapy in patients with AML or MDS.

We analyzed the 67 of 278 patients with newly-diagnosed AML or 'high-risk' MDS, treated in 1994 and 1995, who developed pneumonia during course 1 of their induction therapy. Pneumonia responded to treatment in 66%, but outcome depended on when pneumonia was diagnosed. Patients with pneumonia diagnosed during week 1 or 2 (group 2 patients) had the lowest response rate (43%). Patients who developed pneumonia in the 3rd week after treatment initiation had the best outcome with all 16 patients recovering. Patients presenting with pneumonia had an intermediate response rate (75%). The different patient groups were comparable with regard to age, underlying disease, prophylactic therapy, and G-CSF application. Although a lower CR rate was not entirely responsible for the lower response rate in group 2, failure to achieve CR predicted unsuccessful treatment of pneumonia in all groups. Fungal pathogens appeared more common in group 2 patients. However, in these patients, administration of amphotericin B was associated with a significantly higher failure rate (15/21 failures vs 2/9 who received no amphotericin B). We conclude that patients who develop pneumonia during week 1 or 2 are a high-risk group, and that use of amphotericin B indicates a particularly poor prognosis, although we present data suggesting that earlier use of amphotericin might be beneficial. Furthermore, since achievement of CR was an important prognostic factor in all groups, WBC transfusions particularly from donors given G-CSF should be considered as a therapeutic option. Finally, since time to failure of induction therapy and time to CR were similar in high-risk patients, new chemotherapy regimens could potentially improve both the CR rate and the outcome of pneumonia.

Acute Disease↗
PubMed1995

Effect of interleukin-1 beta converting enzyme inhibitor on acute myelogenous leukemia progenitor proliferation.

Interleukin-1 beta (IL-1 beta) converting enzyme (ICE) is a cysteine protease that specifically cleaves precursor IL-1 beta to its biologically active form. Recent studies have also implicated ICE in the induction of apoptosis in vertebrate cells. Because IL-1 plays a major role in acute myelogenous leukemia (AML) blast proliferation, we sought to investigate the effect of ICE inhibition on AML progenitors. To do this, we used bocaspartyl (benzyl) chloromethylketone (BACMK) an inhibitor designed to penetrate cells and bind covalently to the active site of ICE. Our preliminary experiments showed that incubation of activated peripheral blood cells with 2.5 mumol/L of BAMCK downregulated production of mature IL-1 beta but had no effect on tumor necrosis factor-alpha. To test the effects of the inhibitor on AML cells, we first used the OCI/AML3 cell line. We found that these cells produce IL-1 beta and bind the biotinylated cytokine and that IL-1 inhibitors, such as IL-1 neutralizing antibodies, IL-1 receptor antagonist, and soluble IL-1 receptors, specifically inhibit OCI/AML3 proliferation, indicating that IL-1 beta is an autocrine growth factor for OCI/AML3 cells. The ICE inhibitor suppressed OCI/AML3 growth in a dose-dependent manner (at 0.4 to 4 mumol/L) and downregulated mature IL-1 beta production, as assessed by Western immunoblotting. Similar results were obtained with marrow aspirates from 16 AML patients. The ICE inhibitor suppressed proliferation of AML precursors (by up to 78%; mean, 44%) in a dose-dependent fashion at concentrations ranging from 0.4 to 5 mumol/L but not proliferation of normal marrow progenitors; the suppressive effect was reversed by IL-1 beta. Furthermore, incubation of AML cells with 4 mumol/L BAMCK downregulated the production of mature IL-1 beta, suggesting that the growth-inhibitory effect is mediated through suppression of the biologically active cytokine. Our data indicate that inhibition of ICE suppresses AML blast proliferation and suggest that ICE inhibitors may have a role in future therapies for AML.

Adult↗
PubMed1995

Bayesian sequential monitoring designs for single-arm clinical trials with multiple outcomes.

We present a Bayesian approach for monitoring multiple outcomes in single-arm clinical trials. Each patient's response may include both adverse events and efficacy outcomes, possibly occurring at different study times. We use a Dirichlet-multinomial model to accommodate general discrete multivariate responses. We present Bayesian decision criteria and monitoring boundaries for early termination of studies with unacceptably high rates of adverse outcomes or with low rates of desirable outcomes. Each stopping rule is constructed either to maintain equivalence or to achieve a specified level of improvement of a particular event rate for the experimental treatment, compared with that of standard therapy. We avoid explicit specification of costs and a loss function. We evaluate the joint behaviour of the multiple decision rules using frequentist criteria. One chooses a design by considering several parameterizations under relevant fixed values of the multiple outcome probability vector. Applications include trials where response is the cross-product of multiple simultaneous binary outcomes, and hierarchical structures that reflect successive stages of treatment response, disease progression and survival. We illustrate the approach with a variety of single-arm cancer trials, including bio-chemotherapy acute leukaemia trials, bone marrow transplantation trials, and an anti-infection trial. The number of elementary patient outcomes in each of these trials varies from three to seven, with as many as four monitoring boundaries running simultaneously. We provide general guidelines for eliciting and parameterizing Dirichlet priors and for specifying design parameters.

Bayes Theorem↗
PubMed1995

Molecular characterization of 16p deletions associated with inversion 16 defines the critical fusion for leukemogenesis.

The inversion of chromosome 16 [inv(16)] in acute myeloid leukemia (AML) is associated with a p-arm deletion in a subset of patients. The inversion results in two fusion genes: 5'-CBFB/MYH11-3' on 16p and 5'-MYH11/CBFB-3' on 16q. We have studied cells from 42 patients with inv(16) (38 patients) or t(16;16) (four patients) to define the frequency and characteristics of the deletion further. Using fluorescence in situ hybridization (FISH) with probes from cosmids, cosmid contigs, and yeast artificial chromosomes (YACs), we found that six patients with inv(16) had a deletion of between 150 and 350 kb centromeric to the p-arm inversion breakpoint cluster region (p-ibc). This region was shown to contain the 5' portion of the myosin heavy chain (MYH11) gene. YACs containing the p-ibc, which had been useful as FISH probes in the diagnosis of inv(16), detected the inversion in deletion as well as nondeletion patient cells. Thus, the deleted region identified in patients is entirely contained within the human genomic content of the YACs. Southern blot experiments using probes flanking the p-ibc indicated that the deletion removes segments within 10 kb centromeric of the p-ibc. Reverse transcription-polymerase chain reaction (RT-PCR) using primers from the 5' region of CBFB and the 3' region of MYH11 (distal to the p-ibc) produced the 5'-CBFB/MYH11-3' chimeric transcript in inv(16)/del patients. These data confirm that the 5'-CBFB/MYH11-3' chimeric transcript, rather than the reciprocal 5'-MYH11/CBFB-3', is the critical product for chromosome 16-related leukemogenesis.

Acute Disease↗
PubMed1995

Detection of residual leukemic cells in patients with acute promyelocytic leukemia by the fluorescence in situ hybridization method: potential for predicting relapse.

The translocation between chromosomes 15 and 17, t(15;17)(q22-24;q11-21), is present in the bone marrow cells of most patients with acute promyelocytic leukemia (APL). Although conventional cytogenetic methods are useful for diagnosing this disease, difficulties are experienced in detecting residual disease among those patients who have achieved remission. In this study, we used the fluorescence in situ hybridization (FISH) method to attempt to detect residual leukemic cells in 10 APL patients in clinical remission. The duration of remission ranged from 2 to 93 months at the time of study. Multiple bone marrow samples were analyzed by FISH in most patients. In 6 patients, no cell with t(15;17) was found. These patients remain in complete remission at present (approximately 25 to 33 months since first studied by FISH). In 4 patients, low frequencies of cells with t(15;17) were observed in at least one bone marrow sample examined. All of these patients relapsed within 1 to 14 months. No cell with t(15;17) was identified by the conventional G-banding method in any sample. The FISH results correlated well with that of a two-round nested reverse transcription polymerase chain reaction assay that was performed on the same samples. Thus, our study suggests that FISH is potentially a useful tool for detecting residual APL cells and for identifying patients at high risk of relapse.

Base Sequence↗
PubMed1995

The contribution of Auer rods to the classification and prognosis of myelodysplastic syndromes.

Auer rods were first recognized at the beginning of this century. Their presence soon became considered to be an unequivocal manifestation of a leukemic process. Possibly influenced by this long-held assumption, in 1982 the French-American-British co-operative group (FAB) incorporated the presence of Auer rods into a classification system of the myelodysplastic syndromes that remains in widespread clinical usage today. Although unsubstantiated at the time, the presence of Auer rods was suggested to indicate a rapidly progressive disorder and a poor prognosis. In the absence of studies confirming the utility of Auer rods as a diagnostic criterion, the FAB classification system of myelodysplastic syndromes has been widely used to allocate therapy. In this review we examine the early descriptions of Auer rods and critically evaluate the studies examining the value their presence has in the classification and prognosis of patients with myelodysplastic syndromes.

Humans↗