Scott C Howard

Uniformed Services University of the Health Sciences, Bethesda, MD, USA

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Publications (94)831.48 Total impact

  • Article: Paediatric cancer in low-income and middle-income countries.
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    ABSTRACT: Patterns of cancer incidence across the world have undergone substantial changes as a result of industrialisation and economic development. However, the economies of most countries remain at an early or intermediate stage of development-these stages are characterised by poverty, too few health-care providers, weak health systems, and poor access to education, modern technology, and health care because of scattered rural populations. Low-income and middle-income countries also have younger populations and therefore a larger proportion of children with cancer than high-income countries. Most of these children die from the disease. Chronic infections, which remain the most common causes of disease-related death in all except high-income countries, can also be major risk factors for childhood cancer in poorer regions. We discuss childhood cancer in relation to global development and propose strategies that could result in improved survival. Education of the public, more and better-trained health professionals, strengthened cancer services, locally relevant research, regional hospital networks, international collaboration, and health insurance are all essential components of an enhanced model of care.
    The lancet oncology 03/2013; 14(3):e104-16. · 14.47 Impact Factor
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    Article: New policies to address the global burden of childhood cancers.
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    ABSTRACT: Childhood cancer is a major global health issue. Every year, almost 100 000 children die from cancer before the age of 15 years, more than 90% of them in resource-limited countries. Here, we review the key policy issues for the delivery of better care, research, and education of professionals and patients. We present a key list of time-limited proposals focusing on change to health systems and research and development. These include sector and system reforms to make care affordable to all, policies to promote growth of civil society around both cancer and Millennium Development Goals, major improvements to public health services (particularly the introduction of national cancer plans), improved career development, and increased remuneration of specialist health-care workers and government support for childhood cancer registries. Research and development proposals focus on sustainable funding, the establishment of more research networks, and clinical research specifically targeted at the needs of low-income and middle-income countries. Finally, we present proposals to address the need for clinical trial innovation, the complex dichotomy of regulations, and the threats to the availability of data for childhood cancers.
    The lancet oncology 03/2013; 14(3):e125-35. · 14.47 Impact Factor
  • Article: Prognostic impact of absolute lymphocyte counts at the end of remission induction in childhood acute lymphoblastic leukemia.
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    ABSTRACT: BACKGROUND: Absolute lymphocyte counts (ALC) during treatment have been associated with outcome in children and adults with hematologic malignancies. However, the impact of ALC relative to that of other prognostic factors on the outcome of children with acute lymphoblastic leukemia (ALL) treated in recent trials is unknown. METHODS: Outcomes of 399 patients aged ≤18 years with newly diagnosed ALL who were enrolled in the Total Therapy XV study at St. Jude Children's Research Hospital were analyzed according to ALC at the end of remission induction therapy. RESULTS: An ALC ≥500 cells/μL was significantly more prevalent among patients with B-lineage ALL, in those with favorable presenting features, and in those who achieved negative minimal residual disease (MRD) status on day 43 of treatment. Both overall survival (OS) and event-free survival (EFS) were superior among patients with higher ALC, but only the association with OS was statistically significant in a univariate analysis. In multivariable analyses, ALC was not a significant predictor of outcome after controlling for age, leukocyte count, lineage, risk group, and MRD status at the end of induction (P > .1 for all comparisons). However, among MRD-negative patients, those with low ALC had a 5-year OS rate of 84.2% ± 8.9% versus 97.3% ± 1.0% for patients with higher ALC (P = .036). CONCLUSIONS: ALC at the end of induction is related to favorable presenting features and good initial treatment response but does not independently predict outcome in the context of contemporary, MRD-guided therapy. Cancer 2013;. © 2013 American Cancer Society.
    Cancer 03/2013; · 4.77 Impact Factor
  • Article: POND4Kids: A Global Web-based Database for Pediatric Hematology and Oncology Outcome Evaluation and Collaboration.
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    ABSTRACT: The Pediatric Oncology Network Database, (www.pond4kids.org, POND), is a secure, web-based, multilingual pediatric hematology/oncology database created for use in countries with limited resources to meet various clinical data management needs including cancer registration, delivery of protocol-based care, outcome evaluation, and assessment of psychosocial support programs. Established as a part of the International Outreach Program at St. Jude Children's Research Hospital in Memphis, Tennessee, POND serves as a tool for oncology units to store patient data for easy retrieval and analysis and to achieve uniform data collection to facilitate meaningful comparison of information among centers. Launched in 2003, POND now has 233 sites registered with over 1,000 users in 66 countries. However, adoption and usage of POND varies widely among sites. This paper reviews some of the challenges to developing a global collaborative clinical platform based on the experiences of developing POND. The paper also presents a case study of POND use in Guatemala, where the Guatemalan National Oncology Unit (UNOP) has developed extensive internal and external global collaborations using POND.
    Studies in health technology and informatics 01/2013; 183:251-6.
  • Article: The cost effectiveness of treating paediatric cancer in low-income and middle-income countries: a case-study approach using acute lymphocytic leukaemia in Brazil and Burkitt lymphoma in Malawi.
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    ABSTRACT: Approximately 90% of children with cancer reside in low-income and middle-income countries (LMIC) where healthcare resources are scarce and allocation decisions difficult. The cost effectiveness of treating childhood cancers in these settings is unknown. The objective of the present work was to determine cost-effectiveness thresholds for common paediatric cancers using acute lymphoblastic leukaemia (ALL) in Brazil and Burkitt lymphoma (BL) in Malawi as examples. Disability-adjusted life years (DALYs) prevented by treatment were compared to the gross domestic product (GDP) per capita of each country to define cost-effectiveness thresholds using WHO-CHOICE ('CHOosing Interventions that are Cost-Effective') guidelines. The case examples were selected due to the data available and because ALL and BL both have the potential to yield significant health gains at a low cost per patient treated. The key findings were as follows: the 3:1 cost/DALY prevented to GDP/capita ratio for ALL in Brazil was US$771 225; expenditures below this threshold were cost effective. Costs below US$257 075 (1:1 ratio) were considered very cost effective. Analogous thresholds for BL in Malawi were US$42 729 and US$14 243. Actual costs were far less. In Brazil, US$16 700 was spent to treat each patient while in Malawi total drug costs were less than US$50 per child. In summary, treatment of certain paediatric cancers in LMIC is very cost effective. Future research should evaluate actual treatment and infrastructure expenditures to help guide policymakers.
    Archives of Disease in Childhood 11/2012; · 2.88 Impact Factor
  • Article: Outcome of children treated for relapsed acute lymphoblastic leukemia in Central America.
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    ABSTRACT: BACKGROUND: Outcomes for relapsed childhood acute lymphoblastic leukemia (ALL) have not been documented in resource-limited settings. This study examined survival after relapse for children with ALL in Central America. METHODS: A retrospective cohort study was performed and included children with first relapse of ALL in Guatemala, Honduras, or El Salvador between 1990 and 2011. Predictors of subsequent event-free survival (EFS) and overall survival (OS) were examined. RESULTS: There were 755 children identified with relapsed disease. The median time from diagnosis to relapse was 1.7 years (interquartile range, 0.8-3.1 years). Most relapses occurred during (53.9%) or following (24.9%) maintenance chemotherapy, and the majority occurred in the bone marrow (63.1%). Following the initial relapse, subsequent 3-year EFS (± standard error) and OS were 22.0% ± 1.7%, and 28.2% ± 1.9%, respectively. In multivariable analysis, worse postrelapse survival was associated with age ≥ 10 years, white blood cell count ≥ 50 × 10(9) /L, and positive central nervous system status at the original ALL diagnosis, relapse that was not isolated central nervous system or testicular, and relapse < 36 months following diagnosis. Site and time to relapse were used to identify a favorable risk group whose 3-year EFS and OS were 50.0% ± 8.9% and 68.0% ± 8.1%, respectively. CONCLUSIONS: Prognosis after relapsed ALL in Central America is poor, but a substantial number of those with favorable risk features have prolonged survival, despite lack of access to stem cell transplantation. Stratification by risk factors can guide therapeutic decision-making. Cancer 2012. © 2012 American Cancer Society.
    Cancer 11/2012; · 4.77 Impact Factor
  • Article: Use of joint commission international standards to evaluate and improve pediatric oncology nursing care in Guatemala.
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    ABSTRACT: BACKGROUND: Inadequate nursing care is a major impediment to development of effective programs for treatment of childhood cancer in low-income countries. When the International Outreach Program at St. Jude Children's Research Hospital established partner sites in low-income countries, few nurses had pediatric oncology skills or experience. A comprehensive nursing program was developed to promote the provision of quality nursing care, and in this manuscript we describe the program's impact on 20 selected Joint Commission International (JCI) quality standards at the National Pediatric Oncology Unit in Guatemala. We utilized JCI standards to focus the nursing evaluation and implementation of improvements. These standards were developed to assess public hospitals in low-income countries and are recognized as the gold standard of international quality evaluation. METHODS: We compared the number of JCI standards met before and after the nursing program was implemented using direct observation of nursing care; review of medical records, policies, procedures, and job descriptions; and interviews with staff. RESULTS: In 2006, only 1 of the 20 standards was met fully, 2 partially, and 17 not met. In 2009, 16 were met fully, 1 partially, and 3 not met. Several factors contributed to the improvement. The pre-program quality evaluation provided objective and credible findings and an organizational framework for implementing change. The medical, administrative, and nursing staff worked together to improve nursing standards. CONCLUSION: A systematic approach and involvement of all hospital disciplines led to significant improvement in nursing care that was reflected by fully meeting 16 of 20 standards. Pediatr Blood Cancer © 2012 Wiley Periodicals, Inc.
    Pediatric Blood & Cancer 09/2012; · 1.89 Impact Factor
  • Article: Delayed diagnosis of leukemia and association with morbid-mortality in children in pernambuco, Brazil.
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    ABSTRACT: The objectives of this study were to describe the interval between symptom onset and diagnosis of acute leukemia, to assess risk factors for delayed diagnosis, and its effect on early morbid-mortality and event-free survival (EFS). Records of children aged 1 month to 18 years diagnosed with acute leukemia were reviewed for clinical, demographic, and health care provider factors, and for time to diagnosis. Of 288 patients diagnosed, 55% had a delay in diagnosis. The median time to diagnosis was 31 days. There were significant associations between the diagnostic delay and the distance from the tertiary care hospital (P=0.04), initial consultation in an outpatient clinic (P=0.04), presenting symptoms of bone/joint pain (P=0.04), family with more than 3 children (P=0.02), birth order of third or greater (P=0.009), paternal age <30 years (P=0.03), and paternal education <8 years (P=0.008). There was no association between delayed diagnosis and early morbid-mortality or EFS at 5 years. Initial consultation in an outpatient setting, presenting symptoms of bone/joint pain, and birth order of third or greater remained statistically significant in multivariate analyses, but the delay did not have an impact on early morbid-mortality or EFS. Education of primary care providers in atypical presentations of acute leukemia may decrease the diagnostic delay.
    Journal of Pediatric Hematology/Oncology 08/2012; 34(7):e271-6. · 1.16 Impact Factor
  • Article: Association between radiotherapy vs no radiotherapy based on early response to VAMP chemotherapy and survival among children with favorable-risk Hodgkin lymphoma.
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    ABSTRACT: More than 90% of children with favorable-risk Hodgkin lymphoma can achieve long-term survival, yet many will experience toxic effects from radiation therapy. Pediatric oncologists strive for maintaining excellent cure rates while minimizing toxic effects. To evaluate the efficacy of 4 cycles of vinblastine, Adriamycin (doxorubicin), methotrexate, and prednisone (VAMP) in patients with favorable-risk Hodgkin lymphoma who achieve a complete response after 2 cycles and do not receive radiotherapy. Multi-institutional, unblinded, nonrandomized single group phase 2 clinical trial to assess the need for radiotherapy based on early response to chemotherapy. Eighty-eight eligible patients with Hodgkin lymphoma stage I and II (<3 nodal sites, no B symptoms, mediastinal bulk, or extranodal extension) enrolled between March 3, 2000, and December 9, 2008. Follow-up data are current to March 12, 2012. The 47 patients who achieved a complete response after 2 cycles received no radiotherapy, and the 41 with less than a complete response were given 25.5 Gy-involved-field radiotherapy. Two-year event-free survival was the primary outcome measure. A 2-year event-free survival of greater than 90% was desired, and 80% was considered to be unacceptably low. Two-year event-free survival was 90.8% (95% CI, 84.7%-96.9%). For patients who did not require radiotherapy, it was 89.4% (95% CI, 80.8%-98.0%) compared with 92.5% (95% CI, 84.5%-100%) for those who did (P = .61). Most common acute adverse effects were neuropathic pain (2% of patients), nausea or vomiting (3% of patients), neutropenia (32% of cycles), and febrile neutropenia (2% of patients). Nine patients (10%) were hospitalized 11 times (3% of cycles) for febrile neutropenia or nonneutropenic infection. Long-term adverse effects after radiotherapy were asymptomatic compensated hypothyroidism in 9 patients (10%), osteonecrosis and moderate osteopenia in 2 patients each (2%), subclinical pulmonary dysfunction in 12 patients (14%), and asymptomatic left ventricular dysfunction in 4 patients (5%). No second malignant neoplasms were observed. Among patients with favorable-risk Hodgkin lymphoma and a complete early response to chemotherapy, the use of limited radiotherapy resulted in a high rate of 2-year event-free survival. clinicaltrials.gov Identifier: NCT00145600.
    JAMA The Journal of the American Medical Association 06/2012; 307(24):2609-16. · 30.03 Impact Factor
  • Article: Effect of body mass index on the outcome of children with acute myeloid leukemia.
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    ABSTRACT: BACKGROUND: The effect of body mass index (BMI) on the treatment outcomes of children with acute myeloid leukemia (AML) is unclear and needs further evaluation. METHODS: Children with AML (n = 314) who were enrolled in 4 consecutive St. Jude protocols were grouped according to BMI (underweight, <5th percentile; healthy weight, 5th to 85th percentile; and overweight/obese, ≥85th percentile). RESULTS: Twenty-five patients (8%) were underweight, 86 patients (27.4%) were overweight/obese, and 203 patients (64.6%) had healthy weight. The 5-year overall survival rate of overweight/obese patients (46.5% ± 7.3%) was lower than the rate of patients with healthy weight (67.1% ± 4.3%; P < .001); underweight patients also tended to have lower survival rates (50.6% ± 10.7%; P = .18). In a multivariable analysis that was adjusted for age, leukocyte count, French-American-British classification, and study protocols, patients with healthy weight had the best survival rate among the 3 groups (P = .01). When BMI was considered as continuous variable, patients with lower or higher BMI percentiles had worse survival (P = .03). There was no difference in the occurrence of induction failure or relapse among BMI groups, although underweight and overweight/obese patients had a significantly higher cumulative incidence of treatment-related mortality, especially because of infection (P = .009). CONCLUSIONS: An unhealthy BMI was associated with worse survival and more treatment-related mortality in children with AML. Meticulous supportive care with nutritional support and education, infection prophylaxis, and detailed laboratory and physical examination is required for these patients. These measures, together with pharmacokinetics-guided chemotherapy dosing, may improve outcome. Cancer 2012. © 2012 American Cancer Society.
    Cancer 05/2012; · 4.77 Impact Factor
  • Article: Treatment outcomes in black and white children with cancer: results from the SEER database and St Jude Children's Research Hospital, 1992 through 2007.
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    ABSTRACT: Treatment outcome for black patients with cancer has been significantly worse than for their white counterparts. We determined whether recent improved treatment had narrowed the gap in outcome between black and white pediatric patients. In a parallel comparison, we analyzed survival by disease category between black and white patients with childhood cancer registered in one of the 17 cancer registries of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program or treated at St Jude Children's Research Hospital, which provides comprehensive treatment to all patients regardless of their ability to pay, from 1992 to 2000 and from 2001 to 2007. Analysis of the SEER data indicated that in both study periods, black patients had significantly poorer rates of survival than did white patients, with the exception of a few types of cancer. Despite significantly improved treatment outcomes for patients who were treated from 2001 to 2007, the racial difference in survival has actually widened for acute myeloid leukemia and neuroblastoma. By contrast, in the cohorts treated at St Jude Children's Research Hospital, there were no significant differences in survival between black and white patients in either study period, regardless of the cancer type. Importantly, the outcome of treatment for acute lymphoblastic leukemia, acute myeloid leukemia, and retinoblastoma has improved in parallel for both races during the most recent study period. With equal access to comprehensive treatment, black and white children with cancer can achieve the same high cure rates.
    Journal of Clinical Oncology 04/2012; 30(16):2005-12. · 18.37 Impact Factor
  • Article: Resumption of high-dose methotrexate after acute kidney injury and glucarpidase use in pediatric oncology patients.
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    ABSTRACT: High-dose methotrexate (HDMTX)-induced acute kidney injury is a rare but life-threatening complication. The methotrexate rescue agent glucarpidase rapidly hydrolyzes methotrexate to inactive metabolites. The authors retrospectively reviewed glucarpidase use in pediatric cancer patients at their institution and evaluated whether subsequent resumption of HDMTX was tolerated. Clinical data and outcomes of all patients who received glucarpidase after HDMTX administration were reviewed. Of 1141 patients who received 4909 courses of HDMTX, 20 patients (1.8% of patients, 0.4% of courses) received 22 doses of glucarpidase. The median glucarpidase dose was 51.6 U/kg (range, 13-65.6 U/kg). At the time of administration, the median plasma methotrexate concentration was 29.1 μM (range, 1.3-590.6 μM). Thirteen of the 20 patients received a total of 39 courses of HDMTX therapy after glucarpidase. The median time to complete methotrexate excretion was 355 hours (range, 244-763 hours) for the HDMTX course during which glucarpidase was administered, 90 hours (range, 66-268 hours) for the next HDMTX course, and 72 hours (range, 42-116 hours) for subsequent courses. The median peak serum creatinine level during these HDMTX courses was 2.2 mg/dL (range, 0.8-9.6 mg/dL), 0.8 mg/dL (range, 0.4-1.6 mg/dL), and 0.6 mg/dL (range, 0.4-0.9 mg/dL), respectively. One patient experienced nephrotoxicity upon rechallenge with HDMTX. Renal function eventually returned to baseline in all patients, and no patient died as a result of methotrexate toxicity. The current results indicated that it is possible to safely resume HDMTX therapy after glucarpidase treatment for HDMTX-induced acute kidney injury.
    Cancer 01/2012; 118(17):4321-30. · 4.77 Impact Factor
  • Article: Low socioeconomic status is associated with prolonged times to assessment and treatment, sepsis and infectious death in pediatric fever in El Salvador.
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    ABSTRACT: Infection remains the most common cause of death from toxicity in children with cancer in low- and middle-income countries. Rapid administration of antibiotics when fever develops can prevent progression to sepsis and shock, and serves as an important indicator of the quality of care in children with acute lymphoblastic leukemia and acute myeloid leukemia. We analyzed factors associated with (1) Longer times from fever onset to hospital presentation/antibiotic treatment and (2) Sepsis and infection-related mortality. This prospective cohort study included children aged 0-16 years with newly diagnosed acute leukemia treated at Benjamin Bloom Hospital, San Salvador. We interviewed parents/caregivers within one month of diagnosis and at the onset of each new febrile episode. Times from initial fever to first antibiotic administration and occurrence of sepsis and infection-related mortality were documented. Of 251 children enrolled, 215 had acute lymphoblastic leukemia (85.7%). Among 269 outpatient febrile episodes, median times from fever to deciding to seek medical care was 10.0 hours (interquartile range [IQR] 5.0-20.0), and from decision to seek care to first hospital visit was 1.8 hours (IQR 1.0-3.0). Forty-seven (17.5%) patients developed sepsis and 7 (2.6%) died of infection. Maternal illiteracy was associated with longer time from fever to decision to seek care (P = 0.029) and sepsis (odds ratio [OR] 3.06, 95% confidence interval [CI] 1.09-8.63; P = 0.034). More infectious deaths occurred in those with longer travel time to hospital (OR 1.36, 95% CI 1.03-1.81; P = 0.031) and in families with an annual household income <US$2,000 (OR 13.90, 95% CI 1.62-119.10; P = 0.016). Illiteracy, poverty, and longer travel times are associated with delays in assessment and treatment of fever and with sepsis and infectious mortality in pediatric leukemia. Providing additional education to high-risk families and staying at a nearby guest house during periods of neutropenia may decrease sepsis and infectious mortality.
    PLoS ONE 01/2012; 7(8):e43639. · 4.09 Impact Factor
  • Article: Thrombolytic therapy for central venous catheter occlusion.
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    ABSTRACT: Long-term central venous catheters have improved the quality of care for patients with chronic illnesses, but are complicated by obstructions which can result in delay of treatment or catheter removal. This paper reviews thrombolytic treatment for catheter obstruction. Literature from Medline searches using the terms "central venous catheter", "central venous access device" OR "central venous line" associated with the terms "obstruction", "occlusion" OR "thrombolytic" was reviewed. Efficacy of thrombolytic therapy, central venous catheter clearance rates and time to clearance were assessed. Alteplase, one of the current therapies, clears 52% of obstructed catheters within 30 min with 86% overall clearance (after 2 doses, when necessary). However, newer medications may have higher efficacy or shorter time to clearance. Reteplase cleared 67-74% within 30-40 min and 95% of catheters overall. Occlusions were resolved in 70 and 83% of patients with one and 2 doses of tenecteplase, respectively. Recombinant urokinase cleared 60% of catheters at 30 min and 73% overall. Alfimeprase demonstrated rapid catheter clearance with resolution in 40% of subjects within 5 min, 60% within 30 min, and 80% within 2 h. Additionally, urokinase prophylaxis decreased the incidence of catheter occlusions from 16-68% in the control group to 4-23% in the treatment group; in some studies, rates of catheter infections were also decreased in the urokinase group. Thrombolytic agents successfully clear central venous catheter occlusions in most cases. Newer agents may act more rapidly and effectively than currently utilized therapies, but randomized studies with direct comparisons of these agents are needed to determine optimal management for catheter obstruction.
    Haematologica 12/2011; 97(5):641-50. · 6.42 Impact Factor
  • Article: Pediatric oncology research in low income countries: ethical concepts and challenges.
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    ABSTRACT: Uneven strides in research and care have led to discrepancies in childhood cancer outcomes between high and low income countries (LICs). Collaborative research may help improve outcomes in LICs by generating knowledge for local scientific communities, augmenting knowledge translation, and fostering context-specific evaluation of treatment protocols. However, the risks of such research have received little attention. This paper investigates the relationship between pediatric oncology research in LICs and four core issues in the ethics literature: standard of care, trial benefits, ethics review, and informed consent. Our aims are to highlight the importance of this field and the need for further inquiry.
    Pediatric Blood & Cancer 12/2011; 58(4):492-7. · 1.89 Impact Factor
  • Article: Dexamethasone exposure and asparaginase antibodies affect relapse risk in acute lymphoblastic leukemia.
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    ABSTRACT: We have previously hypothesized that higher systemic exposure to asparaginase may cause increased exposure to dexamethasone, both critical chemotherapeutic agents for acute lymphoblastic leukemia. Whether interpatient pharmaco-kinetic differences in dexamethasone contribute to relapse risk has never been studied. The impact of plasma clearance of dexamethasone and anti-asparaginase antibody levels on risk of relapse was assessed in 410 children who were treated on a front-line clinical trial for acute lymphoblastic leukemia and were evaluable for all pharmacologic measures, using multivariate analyses, adjusting for standard clinical and biologic prognostic factors. Dexamethasone clearance (mean ± SD) was higher (P = 3 × 10(-8)) in patients whose sera was positive (17.7 ± 18.6 L/h per m(2)) versus nega-tive (10.6 ± 5.99 L/h per m(2)) for anti-asparaginase antibodies. In multivariate analyses, higher dexamethasone clearance was associated with a higher risk of any relapse (P = .01) and of central nervous system relapse (P = .014). Central nervous system relapse was also more common in patients with anti-asparaginase antibodies (P = .019). In conclusion, systemic clearance of dexamethasone is higher in patients with anti-asparaginase antibodies. Lower exposure to both drugs was associated with an increased risk of relapse.
    Blood 11/2011; 119(7):1658-64. · 9.90 Impact Factor
  • Article: A sustainable model for pediatric oncology nursing education in low-income countries.
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    ABSTRACT: Effectiveness of a nurse educator in the pediatric oncology unit in Guatemala was assessed by measuring completion of an education course, chemotherapy and central line competency, continuing education, and cost. All newly hired nurses completed the education course. Of the nurses employed, 86% participated in the chemotherapy course, and 93% achieved competency; 57% participated in the central line course, and 79% achieved competency. The nurses completed a mean of 26 hours continuing education yearly. The annual direct cost of the educator ($244/nurse) was markedly less than other models. This is an effective and sustainable means to educate nurses in low-income countries.
    Pediatric Blood & Cancer 11/2011; 58(2):163-6. · 1.89 Impact Factor
  • Article: Treatment-related mortality in children with acute myeloid leukaemia in Central America: incidence, timing and predictors.
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    ABSTRACT: Cure rates in paediatric acute myeloid leukaemia in low-income countries lag behind those in high-income countries, in part secondary to higher rates of treatment-related mortality. Patterns of treatment-related mortality are likely to differ between low and high-income centres. Understanding low-income setting patterns is necessary before effective interventions aimed at decreasing treatment-related mortality can be designed. Our aim was to describe the incidence, timing and predictors of treatment-related mortality among Central American children with acute myeloid leukaemia. We evaluated patients younger than 21 years diagnosed with acute myeloid leukaemia from 2000 to 2008 in El Salvador, Honduras or Guatemala. Biologic, socioeconomic and nutritional variables collected prospectively were examined as potential predictors of treatment-related mortality. Among 279 patients, treatment-related mortality occurred in 65 (23%). Of 65 deaths, 51 (78.5%) occurred before or during induction, resulting in an early death rate of 18.3%. The most common causes of treatment-related mortality were infection (29/65; 45%) and haemorrhage (13/65; 20%). Infection accounted for 33% of treatment-related mortality before remission induction therapy versus 40% during induction and 77% after induction (P = 0.03). Rates of treatment-related mortality did not vary between time periods 1 and 2 (24.8% versus 21.4%; P = 0.32). Only lower initial platelet count predicted early death (odds ratio per 10 × 10(9)/L = 0.88, 95% Confidence Interval (CI) 0.79-0.97; P < 0.001). Treatment-related mortality remains a significant cause of treatment failure. Supportive care interventions are needed. Children presenting with low initial platelet counts were at highest risk of induction death, suggesting that transfusion practices should be evaluated.
    European journal of cancer (Oxford, England: 1990) 11/2011; 48(9):1363-9. · 4.12 Impact Factor
  • Article: Safety and immunogenicity of live attenuated and inactivated influenza vaccines in children with cancer.
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    ABSTRACT: The safety and immunogenicity of live, attenuated influenza vaccine (LAIV) has not been compared to that of the standard trivalent inactivated vaccine (TIV) in children with cancer. Randomized study of LAIV versus TIV in children with cancer, age 2-21 years, vaccinated according to recommendations based on age and prior vaccination. Data on reactogenicity and other adverse events and blood and nasal swab samples were obtained following vaccination. Fifty-five eligible subjects (mean age, 10.4 years) received vaccine (28 LAIV/27 TIV). Both vaccines were well tolerated. Rhinorrhea reported within 10 days of vaccination was similar in both groups (36% LAIV vs 33% TIV, P > .999). Ten LAIV recipients shed virus; the latest viral shedding was detected 7 days after vaccination. Immunogenicity data were available for 52 subjects, or 26 in each group. TIV induced significantly higher postvaccination geometric mean titers against influenza A viruses (P < .001), greater seroprotection against influenza A/H1N1 (P = .01), and greater seroconversion against A/H3N2 (P = .004), compared with LAIV. No differences after vaccination were observed against influenza B viruses. As expected, serum antibody response against influenza A strains were greater with TIV than with LAIV in children with cancer. Both vaccines were well tolerated, and prolonged viral shedding after LAIV was not detected. Clinical Trials Registration: NCT00906750.
    The Journal of Infectious Diseases 09/2011; 204(10):1475-82. · 6.41 Impact Factor
  • Article: Combination chemotherapy with clofarabine, cyclophosphamide, and etoposide in children with refractory or relapsed haematological malignancies.
    British Journal of Haematology 08/2011; 156(2):275-9. · 4.94 Impact Factor

Institutions

  • 2013
    • Uniformed Services University of the Health Sciences
      Bethesda, MD, USA
  • 2004–2013
    • St. Jude Children's Research Hospital
      • Department of Oncology
      Memphis, TN, USA
  • 2011–2012
    • Children's Hospital Los Angeles
      • Division of Hematology-Oncology
      Los Angeles, CA, USA
    • SickKids
      • Division of Hematology/Oncology
      Toronto, Ontario, Canada
  • 2009
    • University of Colorado Denver
      • Department of Pediatrics
      Denver, CO, USA
  • 2008
    • The University of Memphis
      Memphis, TN, USA
  • 2003–2008
    • The University of Tennessee Health Science Center
      • • Department of Orthodontics
      • • Division of General Internal Medicine
      • • Division of Hematology & Oncology
      Memphis, TN, USA
  • 2007
    • Oregon Health and Science University
      • Department of Pediatrics
      Portland, OR, USA