Oxidative stress and neurobehavioral problems in pediatric acute lymphoblastic leukemia patients undergoing chemotherapy

Oxidative Stress in Cerebrospinal Fluid During Treatment in Childhood Acute Lymphoblastic Leukemia

Introduction Central nervous system (CNS) treatment using intrathecal chemotherapy and cranial radiation to enable long-term disease-free survival from childhood acute lymphoblastic leukemia (ALL) comes at the cost of neurotoxic side effects and long-term sequelae. We investigated oxidative stress as a possible mechanism of chemotherapy-induced neurotoxicity in children with ALL. Materials and methods In this case-control study, we estimated the cerebrospinal fluid (CSF) levels of 8-hydroxy-deoxyguanosine (8-OH-dG), a DNA damage product, in children with B-cell ALL and control children. CSF samples were collected at diagnosis, at end of Induction 1, Induction 2, and Induction 2A - consolidation phase. CSF 8-OH-dG levels were compared in children with and without neurotoxicity. Results Children with ALL (n=23) at diagnosis had significantly higher median (interquartile range, IQR) CSF 8-OH-dG levels (ng/mL) compared to controls (n=19) [1.97 (1.59-2.56) Vs 0.65 (0.59-0.82), P<0.001]. CSF 8-OH-dG levels at the end of four weeks, eight weeks, and 16 weeks of chemotherapy were [3.96 (2.85-5.44) ng/mL], 1.00 (0.89-1.09), and 3.73 (2.80-4.39) ng/mL, respectively. Out of 23 children with ALL, 12 developed neurotoxicity; the CSF levels of 8-OH-dG in them were only marginally higher compared to those who did not develop neurotoxicity. The CSF 8-OH-dG levels did not show a significant correlation with the number of doses of methotrexate or vincristine received. Conclusion Chemotherapy increases the CNS oxidative stress as measured by CSF 8-OH-dG levels, with the levels being proportional to the intensity of chemotherapy. Children with neurotoxicity had only marginally higher CSF 8-OH-dG levels as compared to children without neurotoxicity.

Cerebrospinal Fluid Biomarkers in Childhood Leukemias

Involvement of the central nervous system (CNS) in childhood leukemias remains a major cause of treatment failures. Analysis of the cerebrospinal fluid constitutes the most important diagnostic pillar in the detection of CNS leukemia and relies primarily on cytological and flow-cytometry studies. With increasing survival rates, it has become clear that treatments for pediatric leukemias pose a toll on the developing brain, as they may cause acute toxicities and persistent neurocognitive deficits. Preclinical research has demonstrated that established and newer therapies can injure and even destroy neuronal and glial cells in the brain. Both passive and active cell death forms can result from DNA damage, oxidative stress, cytokine release, and acceleration of cell aging. In addition, chemotherapy agents may impair neurogenesis as well as the function, formation, and plasticity of synapses. Clinical studies show that neurocognitive toxicity of chemotherapy is greatest in younger children. This raises concerns that, in addition to injury, chemotherapy may also disrupt crucial developmental events resulting in impairment of the formation and efficiency of neuronal networks. This review presents an overview of studies demonstrating that cerebrospinal fluid biomarkers can be utilized in tracing both CNS disease and neurotoxicity of administered treatments in childhood leukemias.

Influence of Inflammatory and Oxidative Stress Pathways on Longitudinal Symptom Experiences in Children With Leukemia

PURPOSE

The purpose of this study was to explore the influence of oxidative stress (F2-isoprostanes) and inflammatory (interleukin [IL]-8) biomarkers on symptom trajectories during the first 18 months of childhood leukemia treatment.

METHOD

A repeated-measures design was used to evaluate symptoms experienced by 218 children during treatment. A symptom cluster (fatigue, pain, and nausea) was explored over four time periods: initiation of post-induction therapy, 4 and 8 months into post-induction therapy, and the beginning of maintenance therapy (12 months postinduction). F2-isoprostanes and IL-8 were evaluated in cerebrospinal fluid (CSF) samples collected at baseline (diagnosis) and then at the four time periods. The longitudinal relationships of these biomarkers with the symptom cluster were examined using the longitudinal parallel process.

RESULTS

Pain and fatigue levels were highest during the post-induction phases of treatment and decreased slightly during maintenance therapy, while nausea scores were relatively stable. Even in the later phases of treatment, children continued to experience symptoms. CSF levels of the biomarkers increased during the post-induction phases of treatment. Early increases in the biomarkers were associated with more severe symptoms during the same period; patients who had increased biomarkers over time also experienced more severe symptoms over time.

CONCLUSIONS

Findings reveal that children experienced symptoms throughout the course of leukemia treatment and support hypothesized longitudinal relationships of oxidative stress and inflammatory biomarkers with symptom severity. Activation of the biomarker pathways during treatment may explain underlying mechanisms of symptom experiences and identify which children are at risk for severe symptoms.

Oxidative Stress, Motor Abilities, and Behavioral Adjustment in Children Treated for Acute Lymphoblastic Leukemia

PURPOSE/OBJECTIVES

To examine associations among oxidative stress, fine and visual-motor abilities, and behavioral adjustment in children receiving chemotherapy for acute lymphoblastic leukemia (ALL)
.

DESIGN

A prospective, repeated-measures design
.

SETTING

Two pediatric oncology settings in the southwestern United States.

SAMPLE

89 children with ALL were followed from diagnosis to the end of chemotherapy.

METHODS

Serial cerebrospinal fluid samples were collected during scheduled lumbar punctures and analyzed for oxidative stress biomarkers. Children completed fine motor dexterity, visual processing speed, and visual-motor integration measures at three time points. Parents completed child behavior ratings at the same times.

MAIN RESEARCH VARIABLES

Oxidative stress, fine motor dexterity, visual processing, visual-motor integration, and behavioral adjustment
.

FINDINGS

Children with ALL had below-average fine motor dexterity, visual processing speed, and visual-motor integration following the induction phase of ALL therapy. By end of therapy, visual processing speed normalized, and fine motor dexterity and visual-motor integration remained below average. Oxidative stress measures correlated with fine motor dexterity and visual-motor integration. Decreased motor functioning was associated with increased hyperactivity and anxiety
.

CONCLUSIONS

Oxidative stress occurs following chemo-therapy for childhood ALL and is related to impaired fine motor skills and visual symptoms
.

IMPLICATIONS FOR NURSING

Early intervention should be considered to prevent fine motor and visual-spatial deficits, as well as behavioral problems.

Trajectories of Obesity and Overweight Rates Among Survivors of Childhood Acute Lymphoblastic Leukemia

PURPOSE/OBJECTIVES

To describe the trajectories of obesity/overweight rates by age group among survivors of childhood acute lymphoblastic leukemia (ALL) from diagnosis through several years post-therapy.

DESIGN

Longitudinal, descriptive.

SETTING

Hematology/oncology clinic in the southwestern United States.

SAMPLE

62 child and adolescent ALL survivors receiving treatment and follow-up care from 1999-2013.

METHODS

Retrospective chart review of height, weight, and body mass index.

MAIN RESEARCH VARIABLES

Annual obesity/overweight rates and developmental age groups.

FINDINGS

Different trajectories of obesity/overweight rates existed among age groups. Forty-seven percent of adolescents met the Centers for Disease Control and Prevention criteria for obesity/overweight status at some point following diagnosis, compared to 68% of school-age and 73% of preschool children. Preschool children demonstrated the most rapid rate increase following diagnosis, with a particularly susceptible period in the years immediately following therapy. Obesity/overweight persistence was most characteristic of school-age children.

CONCLUSIONS

Important variations in rate and pattern of weight status trajectories exist by age group, demonstrating that children diagnosed with ALL during the preschool and school-age developmental years have the greatest vulnerability of developing obesity/overweight status.

IMPLICATIONS FOR NURSING

Obesity/overweight prevention efforts are greatly needed in children with ALL, and efforts should occur before ALL treatment completion in preschool and school-age children.

Prevalence and predictors of anxiety and depression after completion of chemotherapy for childhood acute lymphoblastic leukemia: A prospective longitudinal study

BACKGROUND

The months immediately after the completion of treatment for childhood acute lymphoblastic leukemia (ALL) are often regarded as a stressful time for children and families. In this prospective, longitudinal study, the prevalence and predictors of anxiety and depressive symptoms after the completion of treatment were examined.

METHODS

Participants included 160 children aged 2 to 9 years with standard-risk ALL who were enrolled on Children's Oncology Group protocol AALL0331. Parents completed standardized rating scales of their children's emotional-behavioral functioning and measures of coping and family functioning at approximately 1 month, 6 months, and 12 months after diagnosis and again 3 months after the completion of chemotherapy.

RESULTS

At 3 months off therapy, approximately 24% of survivors had at-risk/clinically elevated anxiety scores and 28% had elevated depression scores, which are significantly higher than the expected 15% in the general population (P = .028 and .001, respectively). Patients with elevated anxiety 1 month after diagnosis were at greater risk of off-therapy anxiety (odds ratio, 4.1; 95% confidence interval, 1.31-12.73 [P = .022]) and those with elevated depressive symptoms 6 months after diagnosis were at greater risk of off-therapy depression (odds ratio, 7.88; 95% confidence interval, 2.61-23.81 [P = .0002]). In adjusted longitudinal analyses, unhealthy family functioning (P = .008) and less reliance on social support coping (P = .009) were found to be associated with risk of emotional distress. Children from Spanish-speaking families (P = .05) also were found to be at a greater risk of distress.

CONCLUSIONS

A significant percentage of children experience emotional distress during and after therapy for ALL. These data provide a compelling rationale for targeted early screening and psychosocial interventions to support family functioning and coping skills. Cancer 2016;122:1608-17. © 2015 American Cancer Society.

Neurocognitive outcomes in long-term survivors of childhood acute lymphoblastic leukemia treated on contemporary treatment protocols: A systematic review

The intensified administration of chemotherapeutic drugs has gradually replaced cranial radiation therapy (CRT) for the treatment of childhood acute lymphoblastic leukemia (ALL). While CRT is often implicated in neurocognitive impairment in ALL survivors, there is a paucity of the literature that evaluates the persistence of neurocognitive deficits in long-term survivors of pediatric ALL who were treated with contemporary chemotherapy-only protocols. Results from this systematic review concurred to the probable cognitive-sparing effect of chemotherapy-based protocols over CRT in long-term survivors. However, coupled with multiple intrinsic and extrinsic factors, survivors who received chemotherapy treatment still suffered from apparent cognitive impairment, particularly in the attention and executive function domains. Notably, there is evidence to suggest that the late neurotoxic effect of methotrexate on survivors' neurocognitive performance may be dose-related. This review also recommends future pharmacokinetic, neuroimaging and genetic studies to illuminate the multifactorial nature of this subject matter and discusses the potential value of neurochemical, physiological, inflammatory and genetic markers for the prediction of susceptibility to neurocognitive impairment in long-term survivors of childhood ALL.

The influence of oxidative stress on symptom occurrence, severity, and distress during childhood leukemia treatment

PURPOSE/OBJECTIVES

To explore the symptom trajectory during the first 16 months of childhood leukemia treatment and any associations with the oxidative stress pathway measured by cerebrospinal fluid (CSF) concentration of oxidized phosphatidylcholine (PC), the predominant glycerophospholipid in the brain and cell membranes.

DESIGN

Prospective, longitudinal design.

SETTING

Two cancer centers in the southwestern United States.

SAMPLE

36 children (aged 3-14 years) newly diagnosed with acute lymphoblastic leukemia.

METHODS

Symptoms were measured using the Memorial Symptom Assessment Scale at six specific time points during treatment. Biochemical changes in oxidative stress were measured by oxidized PC in the CSF.

MAIN RESEARCH VARIABLES

Childhood cancer symptoms, oxidized PC.

FINDINGS

Significant differences were found in the number of symptoms experienced during the three phases of treatment. Symptom trajectory changes and influence of the oxidative stress pathway on symptom experiences were identified.

CONCLUSIONS

Symptoms experienced during treatment for childhood leukemia are associated with increased oxidative stress.

IMPLICATIONS FOR NURSING

Children with leukemia experience symptoms throughout treatment. Physiologic measures indicate the influence of oxidative stress on symptoms.

Evaluation of Biomarkers of Oxidative Stress and Apoptosis in Patients With Severe Methotrexate Neurotoxicity: A Case Series

Central nervous system (CNS) treatment is an essential part of acute lymphocytic leukemia (ALL) therapy, and the most common CNS treatment is intrathecal (IT) and high-dose intravenous (IV) methotrexate (MTX). Treatment with MTX may cause neurotoxicity, which is often accompanied by neurologic changes, delays in treatment, and prolonged hospital stays. This article reports clinical presentations of 3 patients with severe MTX toxicity as well as levels of oxidative stress and apoptosis biomarkers in cerebrospinal fluid (CSF). Oxidative stress was measured by oxidized phosphatidylcholine (PC), oxidized phosphatidylinositol (PI), and F2 isoprostanes; apoptosis was measured by caspase 3/7 activity. Most consistent biomarker changes in all 3 cases were increases in caspase 3/7 and F2 isoprostanes prior to acute toxicity while increases in oxidized phospholipids occurred slightly later. Progressive increases in F2 isoprostanes and caspase 3/7 activity prior to and/or during acute toxicity suggests MTX induces oxidative stress and an associated increase in apoptosis. These findings support the role of oxidative stress in MTX-related neurotoxicity.

Developing interventions for cancer-related cognitive dysfunction in childhood cancer survivors

Survivors of childhood cancer frequently experience cancer-related cognitive dysfunction, commonly months to years after treatment for pediatric brain tumors, acute lymphoblastic leukemia (ALL), or tumors involving the head and neck. Risk factors for cancer-related cognitive dysfunction include young age at diagnosis, treatment with cranial irradiation, use of parenteral or intrathecal methotrexate, female sex, and pre-existing comorbidities. Limiting use and reducing doses and volume of cranial irradiation while intensifying chemotherapy have improved survival and reduced the severity of cognitive dysfunction, especially in leukemia. Nonetheless, problems in core functional domains of attention, processing speed, working memory and visual-motor integration continue to compromise quality of life and performance. We review the epidemiology, pathophysiology and assessment of cancer-related cognitive dysfunction, the impact of treatment changes for prevention, and the broad strategies for educational and pharmacological interventions to remediate established cognitive dysfunction following childhood cancer. The increased years of life saved after childhood cancer warrants continued study toward the prevention and remediation of cancer-related cognitive dysfunction, using uniform assessments anchored in functional outcomes.

Structural brain alterations in children an average of 5 years after surgery and chemotherapy for brain tumors

Young children with brain tumors are often treated with high-dose chemotherapy after surgery to avoid brain tissue injury associated with irradiation. The effects of systemic chemotherapy on healthy brain tissue in this population, however, are unclear. Our objective was to compare gray and white matter integrity using MRI procedures in children with brain tumors (n = 7, mean age 8.3 years), treated with surgery and high-dose chemotherapy followed by autologous hematopoietic cell rescue (AuHCR) an average of 5.4 years earlier, to age- and gender-matched healthy controls (n = 9, mean age 9.3 years). Diffusion tensor imaging data were collected to evaluate tissue integrity throughout the brain, as measured by mean diffusivity (MD), a marker of glial, neuronal, and axonal status, and fractional anisotropy (FA), an index of axonal health. Individual MD and FA maps were calculated, normalized, smoothed, and compared between groups using analysis of covariance, with age and sex as covariates. Higher MD values, indicative of injury, emerged in patients compared with controls (p < .05, corrected for multiple comparisons), and were especially apparent in the central thalamus, external capsule, putamen, globus pallidus and pons. Reduced FA values in some regions did not reach significance after correction for multiple comparisons. Children treated with surgery and high-dose chemotherapy with AuHCR for brain tumors an average of 5.4 years earlier show alterations in white and gray matter in multiple brain areas distant from the tumor site, raising the possibility for long-term consequences of the tumor or treatment.

Investigating the relationship between COMT polymorphisms and working memory performance among childhood brain tumor survivors

BACKGROUND

Survivors of childhood brain tumors are at increased risk for neurocognitive impairments, including deficits in abilities supported by frontal brain regions. Catechol-O-methyltransferase (COMT) metabolizes dopamine in the prefrontal cortex, with the Met allele resulting in greater dopamine availability and better performance on frontally mediated tasks compared to the Val allele. Given the importance of identifying resiliency factors against the emergence of cognitive late effects, the current study examined the relationship between COMT genotype and working memory performance among childhood brain tumor survivors.

PROCEDURE

Children treated for a brain tumor with conformal radiation therapy (N = 50; mean age at irradiation = 7.41 ± 3.41; mean age at assessment = 13.18 ± 2.88) were administered two computerized measures of working memory (self-ordered search verbal and object tasks). Buccal (cheek) swabs were used to provide tissue from which DNA was extracted.

RESULTS

Findings revealed an association between COMT genotype and performance on the self-ordered verbal (P = 0.03) but not object task (P = 0.33). Better performance was found for the Met/Val group compared to either Met/Met or Val/Val.

CONCLUSIONS

COMT may indicate a potential resiliency factor against neurocognitive effects of cancer and its treatment; however, there is a need for replication with larger samples of childhood brain tumor survivors.

F2-isoprostanes: a measure of oxidative stress in children receiving treatment for leukemia

Acute lymphoblastic leukemia (ALL) is the most prevalent and curable cancer among children and adolescents less than 15 years of age in the United States. Essential for cure of childhood ALL is prophylactic treatment of the central nervous system (CNS), with methotrexate (MTX) being the most widely used drug in this treatment. While CNS treatment has contributed to long-term disease-free survival, resulting declines in academic abilities have been reported. There is growing evidence that CNS treatment with MTX increases oxidative stress, a potential mechanism of CNS injury. This article reports changes in oxidative stress, measured by the biomarker F2-isoprostane (F2-IsoP), in the cerebrospinal fluid (CSF) in 47 children with ALL during the first 18 months of treatment. The number of CSF samples ranged from 5 to 14 during postinduction and from 1 to 9 during continuation. Total doses of intrathecal MTX during postinduction were significantly correlated with the mean and highest concentrations of F2-IsoP during postinduction and the mean concentration of F2-IsoP during continuation. F2-IsoP concentrations during postinduction and continuation were higher in children who received more than six doses of intrathecal MTX. New therapies for a highly curable disease such as childhood leukemia have the potential to be individualized in the future, requiring reliable molecular and biochemical markers, such as oxidative stress indicators. Innovative use of biomarkers has the potential to increase our understanding of treatment-related toxicities and associated symptoms and to inform future therapeutic approaches for optimizing cure and quality of life among children with leukemia.

Children's Oncology Group's 2013 blueprint for research: nursing discipline

Integration of the nursing discipline within cooperative groups conducting pediatric oncology clinical trials provides unique opportunities to maximize nursing's contribution to clinical care, and to pursue research questions that extend beyond cure of disease to address important gaps in knowledge surrounding the illness experience. Key areas of importance to the advancement of the nursing discipline's scientific knowledge are understanding the effective delivery of patient/family education, and reducing illness-related distress, both of which are integral to facilitating parental/child coping with the diagnosis and treatment of childhood cancer, and to promoting resilience and well-being of pediatric oncology patients and their families.

Predictive factors of internalized and externalized behavioral problems in children treated for acute lymphoblastic leukemia

BACKGROUND

Pediatric cancer survivors are at increased risk of various neurological and psychological problems. The prevalence of behavioral problems was assessed in a longitudinal study in pediatric patients with an acute lymphoblastic leukemia (ALL). Multilevel modeling was used to identify associated predictive factors.

PROCEDURE

ALL patients and their parents (n = 138) took part to this study. Patients were treated according to the Dana-Farber Cancer Institute (DFCI) consortium protocols 91-01 or 95-01. Mothers filled out questionnaires providing a measure of behavioral problems for their child at diagnosis and during the subsequent 4 years, and of their perceived familial stress at diagnosis and post-induction.

RESULTS

Prevalence of internalized behavioral problems at diagnosis was increased [42% above 1 standard deviation (SD); P < 0.001], but it normalized over time. Internalized problems resolved more slowly in the presence of medical variables associated with increased stress related to the disease (hospitalization duration, P < 0.001; relapse risk at diagnosis, P < 0.001). Externalized behavioral problems were within the expected normal range, but more sustained over time with the 95-01 than with the 91-01 treatment protocols (P < 0.05), likely due to the type of corticosteroid (CS) used (dexamethasone vs. prednisone).

CONCLUSIONS

Assessment of both internalized and externalized problems is required in this population. The impact of pharmacological variables on externalized behavioral problems is likely related to CS use.

Psychological problems in children with cancer in the initial period of treatment

BACKGROUND

The increasing survival rate of children with cancer because of more refined treatments makes necessary the investigation of psychological burden for the young patients.

OBJECTIVE

The aim of the study was to evaluate the development of psychological problems in children with cancer during the initial 6-month period of intensive treatment.

METHODS

This prospective, comparative study was conducted at one of the largest Greek pediatric oncology units in Athens. The sample comprised 132 children with cancer treated during a 30-month period and 100 children with no cancer as control group. Data were collected using the Rutter instruments for parents and teachers. For patients, it was completed by their parents at 1 (T1), 3 (T2), and 6 months (T3) from diagnosis and by teachers at T3. In the control group, the questionnaire was completed by teachers and parents once.

RESULTS

The comparison of total Rutter scores for patients at T1, T2, and T3, according to parents' responses, showed statistically significant difference (P < .001). The difference in scores for patients (at T3) and control subjects was also significant according to both parents' (P < .00001) and teachers' (P < .001) responses. Children with leukemia had higher score reduction during treatment (P = .009) compared with the rest. Only age had a marginal impact on score of patients at T1 (R = 0.04).

CONCLUSIONS

Based on parental reports, children treated for cancer develop psychological problems during the period of intensive treatment. The development and evolution of these problems depend on their age and type of cancer.

IMPLICATIONS FOR PRACTICE

This information can be used for relevant interventions in specific groups.

Cognitive Emotion Regulation in Children with Acute Lymphoblastic Leukemia

BACKGROUND

Childhood cancer, as one of the life threatening and most serious health problems, considerably influences the cognitive and social functions of children with cancer and their families; however, surprisingly enough, these children are quite compatible with their peers and even function better emotionally compared with normal children. This matter still remains to be a mystery.

METHODS

In this study, the ability of ignoring negative stimuli as a technique of emotion regulation was investigated in children with cancer. For this purpose, 78 children (33 girls and 45 boys aged 3 to 12 years) with pediatric acute lymphoblastic leukemia (ALL), and 89 healthy children (52 girls and 37 boys aged3 to 12 years) participated in this study. At the first stage, a number of positive,negative and neutral pictures were displayed to children. At the second stage, they were asked to identify the pictures from among a collection.

RESULTS

Data analysis by MANOVA indicated that children with cancer, compared with healthy children, could recognize more positive images than negative ones. Furthermore, it was found that age, sex, duration of hospital stay, duration of disease and financial situation had an effect on the difference between the two groups.

CONCLUSION

Positive bias memory can explain low depression and lack of symptoms of post traumatic stress disorder in children with ALL. Attention shifting is multifactorial phenomenon and neurologic factors and family support play important role in this happening.