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C H Pui

Publications and source records attributed to C H Pui.

At least 181 records · Page 10Linked to original sources
PubMed1993

Low leukocyte counts with blast cells in cerebrospinal fluid of children with newly diagnosed acute lymphoblastic leukemia.

BACKGROUND: Treatment of the central nervous system is crucial to the successful treatment of acute lymphoblastic leukemia in children. The intensity and timing of the therapy are based on the presence or predicted risk of central nervous system leukemia as assessed according to criteria that remain controversial. METHODS: The clinical importance of leukemic blast cells detected in cerebrospinal fluid at the time of diagnosis was evaluated in 351 children with acute lymphoblastic leukemia in a randomized trial of intensive chemotherapy. All patients received intrathecal chemotherapy during the first year. Patients considered to be at high risk of relapse because of their clinical and cytogenetic features also received cranial irradiation and intrathecal chemotherapy one year after remission. Patients were considered to have central nervous system leukemia at diagnosis if they had at least 5 leukocytes per microliter of cerebrospinal fluid, with leukemic blast cells apparent in cytocentrifuged preparations, or cranial-nerve palsy; they received additional intrathecal injections of chemotherapeutic agents and cranial irradiation. Patients were retrospectively classified on the basis of cerebrospinal fluid findings: 291 patients had no detectable blast cells, 42 had fewer than 5 leukocytes per microliter and blast cells, and 18 had central nervous system leukemia as defined above. The clinical characteristics and outcomes of treatment in these groups were analyzed. RESULTS: The five-year probability of survival free of relapses confined to the central nervous system in patients with detectable blast cells and fewer than 5 leukocytes per microliter of cerebrospinal fluid was lower than in patients without blast cells (mean [+/- SE], 87 +/- 13 vs. 96 +/- 2 percent), but was not different from the probability in patients with central nervous system leukemia at diagnosis. All such isolated relapses of leukemia in patients with detectable blast cells occurred during the first year of treatment, before scheduled cranial irradiation. In a multivariate analysis, the presence of cerebrospinal fluid blast cells with fewer than 5 leukocytes per microliter was independently related to the risk of relapse confined to the central nervous system. CONCLUSIONS: Patients with leukemic blast cells in their cerebrospinal fluid are at increased risk for central nervous system relapse when cranial irradiation is delayed. Such patients require intensified central nervous system treatment early in the course of therapy.

Adolescent↗
PubMed1993

Continuous infusion of interleukin-2 in children with refractory malignancies.

BACKGROUND: The toxicity of interleukin-2 (IL-2) administered by continuous infusion has not been investigated in children. METHODS: This study enrolled 10 boys and 7 girls with refractory malignancy. Recombinant IL-2 was infused continuously for cycles of 120 hours at doses escalating from 3 to 30 x 10(6) IU/m2 per day. RESULTS: A total of 45 cycles was administered. The most common toxicities included fever, anemia, hypotension (usually responsive to fluid bolus), hyponatremia, oliguria, hypoalbuminemia, nausea, thrombocytopenia, vomiting, and weight gain. Most side effects were correlated significantly with a dosage of 18 x 10(6) IU/m2 or more per day. Respiratory distress was infrequent. Two cycles were interrupted due to severe toxicity (hypotension in one case and confusion in another), but there were no fatalities. During infusion, there was a significant nondose-related increase in serum IL-2 receptor levels. Despite this evidence of immunomodulation, no objective tumor response was noted. CONCLUSIONS: Continuous infusion of IL-2 at doses up to 30 x 10(6) IU/m2 per day can be administered safely to children by this method.

Adolescent↗
PubMed1993

Clinical and biologic relevance of immunologic marker studies in childhood acute lymphoblastic leukemia.

Immunologic marker studies of the lymphoid leukemias have greatly improved the precision of diagnosis of these disorders by providing specific information regarding the lineage and stage of maturation of the malignant cells. Such studies have also enhanced our understanding of normal lymphocyte development, permitting reproducible identification of lymphoid cells in discrete developmental stages. By elucidating the functions of lymphoid cell differentiation antigens, it has been possible to gain insight into the signal transduction mechanisms by which these cells interact among themselves and with other cell types. Similar studies have shown that ALL is an immunophenotypically heterogeneous disease with clinically important subtypes representing clonal expansions of lymphoblasts at different stages of maturation. Furthermore, successful correlation of immunophenotype with certain karyotypic and molecular abnormalities, which appear to underlie most or all leukemias, were made possible by the inclusion of immunologic marker assessment. Interestingly, many of these phenotype-related abnormalities have involved either the Ig or TCR genes, thus providing additional clues to the mechanisms of leukemogenesis. Knowledge of the immunologic features of leukemic cells has been essential for the generation of phenotype-specific response data in the context of modern therapy for ALL. With wider use of intensive treatment, the traditional prognostic distinctions among immunophenotypes have begun to disappear; however, certain classes of agents have more favorable toxicity/efficacy ratios against some immunophenotypes than others, justifying continued efforts to target therapy by immunologic species of ALL. Antibody-toxin conjugates, or immunotoxins, have induced complete responses in preliminary trials and may prove clinically useful, perhaps in combination with chemotherapy, if their toxic side effects can be controlled. Finally, immunologic markers may serve as sensitive targets for the detection of minimal residual disease; the clinical usefulness of this approach will depend on prospective comparisons with molecular methods.

Adult↗
PubMed1993

Cytogenetically different leukemic clones at relapse of childhood acute lymphoblastic leukemia.

Sequential analysis of blast cell chromosomes in 98 cases of acute lymphoblastic leukemia (ALL) disclosed entirely different karyotypes for nine patients at the time of relapse. The presenting clinical, immunophenotypic, and cytogenetic features of this subgroup were similar to those of the 89 patients without major karyotypic shifts. The median length of initial remissions in these nine patients, all of whom received intensive multiagent therapy, was 24 months (range, 6 to 35); responses to subsequent treatment have been uniformly poor. Prominent cytogenetic changes included a gain of modal chromosome numbers in five cases, a loss of chromosomes in two, and the acquisition of an 11q23 rearrangement in three. We propose several different mechanisms to account for these findings. In one, the presence of an entirely different ALL karyotype at relapse may represent induction of secondary leukemia analogous to the well-described entity of epipodophyllotoxin-related secondary acute myeloid leukemia (AML).

Antigens, CD↗
PubMed1993

Progress in the treatment of adolescents with acute lymphoblastic leukemia.

UNLABELLED: BACKGROUND AND METHODS. The authors studied the clinical and biologic features and treatment response of 358 children with acute lymphoblastic leukemia (ALL), including 90 adolescents, treated on a single multiagent protocol (St. Jude Total Study XI, 1984-1988). This was done to clarify whether the disease differed in adolescents and to determine the degree of improvement in treatment outcome produced by this modern intense chemotherapy. RESULTS: Compared with the younger children (1-9 years of age; infants 1 year old or younger excluded; n = 257), adolescents (10-18 years of age; n = 90) were significantly more likely to have adverse prognostic features, including T-cell phenotype, L2 blast cell morphologic characteristics, blasts with negative findings for common ALL antigen, and ploidy other than hyperdiploidy greater than 50. Eighty-six of the 90 (96%) adolescents achieved a complete remission, a rate similar to that of the children (97%). Although the event-free survival (EFS) of adolescents was shorter than that of younger children (5-year EFS of 66 +/- 8% versus 75 +/- 5%, respectively; P = 0.04), in this analysis of consecutively treated patients with ALL it showed a significant statistical and clinical improvement as compared with that in our previous study (St. Jude Total Study X, 1979-1983; 5-year EFS rate of 66 +/- 8% versus 37 +/- 5%, respectively; P < 0.001). Within the adolescent group treated on Total Study XI, the EFS was worse for those older than 15 years of age than for those 10-14 years old (46 +/- 15% versus 75 +/- 8%, respectively; P = 0.007). Toxic effects primarily included myelosuppression without severe sequelae. Approximately 96% of the therapy was administered in the outpatient setting. CONCLUSIONS: The increased frequency of unfavorable clinical and biologic features undoubtedly accounts for the poorer prognosis of adolescents with ALL, a conclusion supported by the lack of independent prognostic importance of age in this study. The authors conclude that approximately two-thirds of adolescents can be cured when treated with this intensive but tolerable therapy, showing that this form of treatment significantly has changed the prognosis of adolescents with ALL.

Adolescent↗
PubMed1993

Prolonged survival of B-lineage acute lymphoblastic leukemia cells is accompanied by overexpression of bcl-2 protein.

Overexpression of bcl-2 delays the onset of apoptosis in lymphohematopoietic cells. We measured levels of bcl-2 protein in normal and leukemic human B-cell progenitors with a specific monoclonal antibody and flow cytometry. Normal immature B cells had low levels of bcl-2 protein; the intensity of fluorescence, expressed as molecules of soluble fluorochrome per cell, within CD10+ cells was 3,460 +/- 1,050 (mean +/- SD; 5 samples). In 16 cases of B-lineage acute lymphoblastic leukemia (ALL), cells had levels of bcl-2 that were strikingly higher than those of their normal counterparts (33,560 +/- 14,570; P < .001 by t-test analysis). We next investigated whether the intensity of bcl-2 expression correlated with the resistance of immature B cells to in vitro culture. In 12 cases of B-lineage ALL, the cells recovered after 7 days of culture on allogeneic bone marrow stromal layers were 69% to 178% (median, 95.5%) of those originally seeded. Prolonged survival of leukemic cells in vitro was observed even in the absence of stromal layers in 6 of these 12 cases; the intensity of bcl-2 protein expression in these cases was 45,000 +/- 13,270, compared with 21,500 +/- 7,260 in the 6 cases in which greater than 99.5% of cells rapidly died by apoptosis under the same culture conditions (P = .003). Five immature B-cell lines, continuously growing in the absence of stroma, had the highest bcl-2 expression (79,400 +/- 20,330). By contrast, most normal CD19+, sIg-immature B cells died despite the presence of bone marrow stromal layers; 9.7% to 28.2% were recovered after 7 days of culture in three experiments. We conclude that abnormal bcl-2 gene expression influences the survival ability of B-cell progenitors. This may contribute to leukemogenesis and explain the aptitude of leukemic lymphoblasts to expand outside the bone marrow microenvironment.

Adolescent↗
PubMed1993

Adverse prognostic features in 251 children treated for acute myeloid leukemia.

Potential predictors of event-free survival (EFS) were assessed in 251 consecutively diagnosed children treated for acute myeloid leukemia (AML) on three successive clinical trials. The lack of significant differences in 4-year EFS for these studies (20% +/- 4%, 29% +/- 4%, and 20% +/- 7%) permitted combined analysis of presenting features. Splenomegaly (P = .002), coagulation abnormalities (P = .001), leukocyte count > or = 10 x 10(9)/L (P = .002), and age > 14 years (P = .01) were statistically significant predictors of a poorer EFS by univariate analysis and retained significance in multivariate analysis. Age < 2 years and monocytic leukemias (often cited as adverse factors in AML) showed no prognostic influence in this study. The estimated relative risk of failure for a child with a single adverse feature at diagnosis was at least 1.4 times greater than that for a patient with no adverse features. For children with two or more adverse features, the relative risk increased by more than threefold. These clinical variables, alone or in combination, may identify important subgroups of patients with AML at high risk for failure and for whom improved or alternative therapies are especially important.

Acute Disease↗
PubMed1993

Avascular femoral head necrosis in pediatric cancer patients.

Avascular femoral head necrosis was identified in 15 patients treated at a major pediatric oncology center from 1974 to 1991. The predominant underlying diagnosis was acute leukemia (lymphoblastic, n = 6; non-lymphoblastic, n = 2); two patients had chronic myeloid leukemia, two Hodgkin's disease, and three other solid tumors. Patients ranged from 7 to 27 years of age at diagnosis of this complication, with a median interval of 25 months (range, 0-11 years) from primary diagnosis. Both steroids and radiation therapy appear implicated in the pathogenesis of avascular necrosis: nine patients had received high cumulative doses of prednisone (3.4-14 g/m2), four had received 35-64.8 Gy local irradiation involving the femoral head, and one underwent total body irradiation (12 Gy). Of the 11 surviving patients, six are asymptomatic and fully active. Two patients have joint pain that is responsive to conservative measures. Severe pain and joint deterioration necessitated arthroplasty in two cases, and a third child is undergoing orthopedic evaluation because of worsening symptoms. Thus, like adult cancer patients, children who receive high doses of steroids or local irradiation involving femoral heads are at risk for avascular necrosis. In patients with chronic myeloid leukemia, the complication may be disease related. Although outcomes in our series are better than those reported in adults, the long period of risk for these children and young adults precludes definitive conclusions.

Adolescent↗
PubMed1993

Clinical implications of cytogenetic and molecular analyses of pediatric acute lymphoblastic leukemia.

The prognosis for children with acute lymphoblastic leukemia (ALL) has improved steadily over the past 20 years. Today, at least two-thirds of newly diagnosed cases are curable with intensified risk-based therapy. The challenge now is to identify, prior to or early in treatment, the one-third of patients who are destined to relapse, so that alternative therapy can be introduced sooner. Cytogenetic studies of lymphoblasts have identified recurring abnormalities of prognostic importance and pinpointed chromosomal regions for molecular analyses. Recently, molecular diagnostic techniques have been developed for the more common cytogenetic subgroups of ALL, defined by the t(1;19) and t(9;22) chromosomal translocations (approximately 10% of cases). Polymerase chain reaction (PCR) techniques can identify these clinically important subgroups in the absence of successful cytogenetic studies. PCR analysis also provides a sensitive and specific tool for the detection of minimal residual disease during apparent (clinically defined) remission. Additionally, molecular studies of cases with specific cytogenetic lesions have helped to clarify the events leading to leukemic transformation of normal lymphoid cells. It is reasonable to expect that improved therapeutic strategies will emerge from findings made with molecular diagnostic and treatment monitoring techniques.

Child↗
PubMed1993

Management of cytogenetic data in multi-center leukemia trials.

This paper provides methods for storing and retrieving cytogenetics data, which must reside jointly in a reference laboratory and in a data co-ordinating center. The major piece of data is the character string that uses the International System for Human Cytogenetic Nomenclature. Simple and complex data retrieval, using Statistical Analysis System (SAS) functions INDEX and SUBSTR, are illustrated. Use of the methods of this paper can save considerable costs in setting up cytogenetic data systems compared with other proposed systems which have come to the authors' attention.

Child↗
PubMed1993

Chlorpromazine with and without lorazepam as antiemetic therapy in children receiving uniform chemotherapy.

We prospectively studied the efficacy and adverse effects of chlorpromazine (30 mg/m2 given intravenously) plus lorazepam (0.04 mg/kg given intravenously) versus chlorpromazine alone in a controlled, double-blind, randomized, parallel-design investigation in 25 children (1.5 to 17.3 years of age) with acute lymphoblastic leukemia. Response to other antiemetics in eight children refusing random assignment to treatment was also evaluated. All children were receiving intravenous infusions of teniposide plus cytarabine, the pharmacokinetics of which were characterized for each of the one to four courses. There were no differences between the 11 patients randomly assigned to receive chlorpromazine alone and the 14 randomly assigned to receive lorazepam plus chlorpromazine in the number of emesis episodes (6.0 vs 5.9; p = 0.53), frequency of dystonic reactions (3% vs 5%), or akathisia (13 vs 10%). The only serious adverse event, symptomatic hypotension, occurred in a boy receiving chlorpromazine plus lorazepam. An exploratory pharmacodynamic analysis revealed that the only variable that correlated with vomiting was cytarabine 1 1/2-hour plasma concentration (p = 0.007). Children who received either chlorpromazine plus lorazepam or chlorpromazine alone had fewer episodes of vomiting than those who received "conventional" antiemetic therapy (6.0 vs 8.6; p = 0.01). We conclude that the severity of emesis is related to the plasma concentration of cytarabine; that intravenously administered chlorpromazine is as effective as chlorpromazine plus lorazepam in preventing chemotherapy-induced vomiting; and that the potential for adverse effects with the addition of lorazepam may be a disadvantage.

Adolescent↗
PubMed1993

Azithromycin for treatment of severe Cryptosporidium diarrhea in two children with cancer.

Two children with cancer received azithromycin for Cryptosporidium-associated diarrhea that was unresponsive to supportive care. One child had choleriform diarrhea requiring daily fluid replacement of up to 65% of his total body weight; the other had protracted diarrhea and wasting. In both cases, administration of azithromycin was followed by prompt clinical improvement.

Administration, Oral↗
PubMed1993

Secondary acute myeloid leukemia in children previously treated with alkylating agents, intercalating topoisomerase II inhibitors, and irradiation.

PURPOSE: Patient records were reviewed to identify cases of secondary acute myeloid leukemia (AML) with clinical and cytogenetic features characteristic of classic epipodophyllotoxin-related AML in patients whose prior treatment for cancer did not include these agents. PATIENTS AND METHODS: Four cases of secondary AML with chromosomal abnormalities involving bands 11q23 and 21q22, in the absence of prior treatment with etoposide or teniposide, were identified among patients treated at St Jude Children's Research Hospital between January 1980 and April 1992. RESULTS: The four identified patients were initially treated for rhabdomyosarcoma, non-Hodgkin's lymphoma (n = 2), and Hodgkins' disease. Prior chemotherapy included relatively low cumulative doses of doxorubicin (median, 150 mg/m2; range, 120 to 375 mg/m2) and cyclophosphamide (median, 3,100 mg/m2; range, 2,250 to 11,400 mg/m2). All four patients had received radiation therapy: 59.4 Gy to the right middle ear for rhabdomyosarcoma; 15 Gy and 12 Gy to the abdomen and right lower quadrant, respectively, for non-Hodgkin's lymphoma; 27 Gy to the right orbit for non-Hodgkin's lymphoma; and 36.6 Gy to the mantle-paraaortic-spleen regions plus 20.4 Gy inverted-Y radiation at relapse for Hodgkin's disease. Secondary AML was diagnosed a median of 38 months after initial diagnosis (range, 14 to 55). Leukemic cell translocations involved band 11q23 in two cases and band 21q22 in two. Although all patients obtained a complete remission (CR), only one remains disease-free (at 34 months), following an allogeneic bone marrow transplant. CONCLUSION: Intercalating topoisomerase II inhibitors (doxorubicin, dactinomycin), when combined with alkylating agents and irradiation, may cause secondary AML.

Acute Disease↗
PubMed1993

Immunophenotypes and karyotypes of leukemic cells in children with Down syndrome and acute lymphoblastic leukemia.

PURPOSE: Immunophenotypes and karyotypes of leukemic cells were analyzed in a large series of Down syndrome patients with acute lymphoblastic leukemia (ALL) to examine the frequency of adverse prognostic features in comparison with other patients with ALL. PATIENTS AND METHODS: Presenting features and leukemic cell characteristics were compared for 76 patients with Down syndrome and 4,733 other patients with newly diagnosed ALL treated on protocols of the Pediatric Oncology Group (POG) and St Jude Children's Research Hospital (SJCRH). Treatment outcome was analyzed for the patients with non-T-cell disease enrolled on a single trial, for whom adequate follow-up data were available. RESULTS: Down syndrome patients had lower platelet counts (P < .01) and were less likely to have an anterior mediastinal mass (P < .01) or CNS leukemia (P = .01). They were significantly more likely to have the pre-B immunophenotype (49% v 25.5%, P < .01) and less likely to have T-cell ALL (5.5% v 16%, P = .01). There was a notable absence among patients with Down syndrome of the t(4;11), t(1;19), and t(9;22), which are chromosomal translocations associated with an adverse prognosis in ALL. Treatment outcome did not differ significantly between patients with Down syndrome and the other children with non-T-cell ALL (P = .21); a third of the treatment failures in the former group resulted from treatment-related toxicities. CONCLUSION: Children with Down syndrome and ALL had a low frequency of adverse clinicobiologic features at diagnosis. However, these findings did not translate into a superior outcome, apparently because of treatment-related toxicity in this group. Future trials should focus on pharmacokinetics and other strategies to reduce toxicity in these compromised patients.

Adolescent↗
PubMed1993

MACOP-B treatment in children and adolescents with advanced diffuse large-cell non-Hodgkin's lymphoma.

From 1986 through 1990, 13 previously untreated pediatric patients with advanced diffuse large-cell non-Hodgkin's lymphoma (LC-NHL) were treated with a 12-week MACOP-B regimen at St Jude Children's Research Hospital. Although 12 patients (92%) achieved a complete response, and one had a partial response, the 2-year event-free survival was only 54 +/- 15% (SE). Seven patients remain in continuous complete remission at a median of 40 months after therapy (range 23-57 months). Relapses occurred at sites of initial involvement in five patients at a median of 3.0 months after remission (range 1.2-8.5 months). Salvage therapy with radiation, and high-dose chemotherapy and bone marrow transplantation produced four durable second remissions. The 2-year overall survival for the entire group is 84 +/- 10% (SE). The 12-week MACOP-B regimen proved feasible in an ambulatory clinic setting with only minimal toxicity. We found that MACOP-B is an effective and tolerable treatment for pediatric patients with LC-NHL but did not provide improved survival over that of a similar group of children treated in previous trials at this institution.

Adolescent↗
PubMed1993

Prognostic factors in childhood acute lymphoblastic leukemia.

Treatment efficacy alters the impact of most prognostic factors. Among clinical features, only age and leukocyte count remain prognostically important. Immunophenotyping is useful for ALL classification and for assignment to specific therapy regimens, but, with the possible exception of CD10 expression, has little prognostic importance in the context of contemporary phenotype- and risk-directed therapy. Cytogenetic features are useful for risk assignment. Hyperdiploidy > 50 chromosomes is associated with a favorable prognosis, whereas Ph+ chromosome and t(4;11) confer an adverse prognosis. Pre-B cases with the t(1;19) do not fare well with antimetabolite-based therapy and should be treated with additional classes of chemotherapeutic agents. Finally, certain specific rearrangements such as dic(9;12) may in fact be associated with favorable prognosis. With the exception of treatment for B-cell ALL (and perhaps transitional pre-B ALL), phenotype- or genotype-directed therapies have not been successfully devised. Selection of treatment for individual patients, therefore, should be based on their estimated risk of failure. For patients with very high-risk leukemia (i.e., those with > 70% likelihood of treatment failure), the use of experimental therapeutic strategies, despite the potential for acute and long-term disabilities, may be justified. For the subset of children in the lower-risk category (< 20% probability of failure), antimetabolite-based therapy should be employed to minimize long-term sequelae.

Child↗
PubMed1993

Serum interleukin-2 receptor levels in Hodgkin disease and other solid tumors of childhood.

Serum levels of interleukin-2 receptor (IL2R) were determined in children with newly diagnosed Hodgkin disease (n = 68), Wilms tumor (n = 20), osteosarcoma (n = 18), rhabdomyosarcoma (n = 18), or Ewing sarcoma (n = 15). Measurements of soluble IL2R were positively correlated with disease stage in Hodgkin disease but not in other tumors. Very high levels of soluble IL2R (> or = 5000 U/ml) were significantly associated with a poorer treatment outcome in Hodgkin disease (p = 0.006) and retained significance in a multivariate analysis (p = 0.03). The addition of soluble IL2R measurements to existing prognostic models may improve risk assignment in children with Hodgkin disease.

Child↗