Robert J. Klaassen

“Low-Risk” Prediction Rule for Pediatric Oncology Patients Presenting With Fever and Neutropenia

PURPOSE To prospectively derive and validate a clinical prediction rule to allow a more tailored approach to the management of pediatric oncology outpatients presenting with fever and neutropenia. PATIENTS AND METHODS The clinical prediction rule was derived over a 1-year period and then validated over the following 8 months in a new set of fever and neutropenia episodes. Patients were excluded if they presented with comorbidity or an abnormal chest x-ray (CXR). RESULTS Significant bacterial infection (SBI; defined as any blood or urine culture positive for bacteria, interstitial or lobar consolidation on CXR, or unexpected death from infection) was documented in 43 of the 227 episodes. Multivariate analysis found four significant factors: bone marrow disease, general appearance unwell on initial examination, monocyte count less than 0.1 x 10(9)/L, and peak oral or oral equivalent temperature greater than 39 degrees C. Only the monocyte count contributed to determining a low-risk group, excluding SBI with 84% sensitivity (95% confidence interval [CI], 61% to 100%), 42% specificity (95% CI, 38% to 46%), and a negative predictive value of 92% (95% CI, 76% to 100%). If the monocyte count was >/= 0.1 x 10(9)/L at the time of presentation (low risk), the incidences of SBI and bacteremia were 8% and 5%, respectively, versus 25% and 17% in the high-risk group. When validated in a new population of 136 episodes of fever and neutropenia, the incidences of SBI and bacteremia in the low-risk group were 12% and 5%, respectively, and 25% and 19% in the high-risk group. CONCLUSION Pediatric oncology outpatients with fever and neutropenia who present with an initial monocyte count of >/= 0.1 x 10(9)/L and do not have comorbidity or an abnormal CXR at the time of presentation are at lower risk for SBI and can be considered for less aggressive initial therapy.

Impact of Caring for a Child With Cancer on Parents’ Health-Related Quality of Life

PURPOSE To compare the health-related quality of life (QOL) of parents of children who are undergoing treatment for cancer with that of Canadian population norms and to identify important parent and child predictors of parental QOL. PATIENTS AND METHODS A total of 411 respondents of 513 eligible parents were recruited from five pediatric oncology centers in Canada between November 2004 and February 2007. Parents were asked to complete a questionnaire booklet that included a measure of adult QOL (SF-36), a measure of child health status (functional status IIR), and questions to assess health-promoting self-care actions (eg, sleep, diet, and exercise habits) and characteristics of the child with cancer (eg, relapse status, time since diagnosis, prognosis, treatment intensity). RESULTS Compared with population norms, parents of children with cancer reported poorer physical and psychosocial QOL in all psychosocial domains (effect sizes range, -0.71 to -1.58) and in most physical health domains (effect sizes range, -0.08 to -0.63). Parent characteristics associated with better parental QOL included better eating, exercise and sleep habits, younger age, and higher income. Child characteristics associated with better parental QOL included better child health status (functional status IIR scores), lower treatment intensity, and longer time since diagnosis. CONCLUSION Parents of children with cancer report poorer QOL compared with population norms. Interventions directed at parents should be included as part of the treatment plan for a child with cancer. Modifiable variables associated with poorer parental QOL, such as sleep quality and diet and exercise habits, indicate those parents most likely to experience poor QOL and may be potential areas for intervention.

Mutations in TRNT1 cause congenital sideroblastic anemia with immunodeficiency, fevers, and developmental delay (SIFD)

Mutations in genes encoding proteins that are involved in mitochondrial heme synthesis, iron-sulfur cluster biogenesis, and mitochondrial protein synthesis have previously been implicated in the pathogenesis of the congenital sideroblastic anemias (CSAs). We recently described a syndromic form of CSA associated with B-cell immunodeficiency, periodic fevers, and developmental delay (SIFD). Here we demonstrate that SIFD is caused by biallelic mutations in TRNT1, the gene encoding the CCA-adding enzyme essential for maturation of both nuclear and mitochondrial transfer RNAs. Using budding yeast lacking the TRNT1 homolog, CCA1, we confirm that the patient-associated TRNT1 mutations result in partial loss of function of TRNT1 and lead to metabolic defects in both the mitochondria and cytosol, which can account for the phenotypic pleiotropy.

Identifying determinants of quality of life of children with cancer and childhood cancer survivors: a systematic review

PurposeThis paper describes a systematic review conducted to identify factors that have been investigated as explanations of variability in the quality of life of children with cancer and childhood cancer survivors. Our purpose was to build an evidence base that could be used to guide and direct future research.MethodsMEDLINE, CINAHL, EMBASE, PsycINFO, Cancerlit, and Sociological Abstracts were searched from the inception of each database to June 15, 2009 using the following search terms: “quality of life,” “health-related quality of life,” “quality adjusted life years,” “health status,” “functional status,” “well-being,” or “patient-reported outcome.” Sample characteristics and information about the relationship between a quality of life domain or total scale score and at least one factor (e.g., child gender or age, coping skills, family income) were extracted from eligible studies.ResultsNine cancer-specific and nine generic QOL questionnaires were used in 58 publications described 239 factors (50 unique factors). The large number of cancer, treatment, child, and family variables considered indicates that extensive research activity has occurred. However, most of the variables identified were examined in only a few studies and most represent medical and treatment variables with less research attention paid to child and family variables.ConclusionsOur study has compiled evidence about determinants of QOL for children with cancer and childhood cancer survivors from the existing literature. Future research can build on this evidence base to expand the range of factors studied as most research to date has focused on medical and treatment factors.

Quality of life during active treatment for pediatric acute lymphoblastic leukemia

The objectives of the study were to describe quality of life (QoL), identify predictors of worse QoL and examine QoL during different phases of active therapy for acute lymphoblastic leukemia (ALL). A multiinstitutional cross‐sectional study was performed in children with ALL. We included children at least 2 months from diagnosis who were receiving treatment in first remission. Parents described QoL using the PedsQL 4.0 Generic Core Scales and the PedsQL 3.0 Acute Cancer Module. The 206 children on treatment for ALL had overall [median 62.5, 95% confidence interval (CI) 34.8–94.4], physical (median 62.5, 95% CI 18.8–100.0) and psychosocial (median 65.4, 95% CI 38.3–94.2) summary scores that were one to two standard deviations lower than population norms. In high‐risk ALL, girls and older children had worse QoL. In standard‐risk ALL, those with lower household incomes and unmarried parents had worse QoL. QoL scores were generally constant across phases of ALL therapy. Children on therapy for ALL have lower QoL compared to healthy children. Age and gender predicted QoL in high‐risk ALL, whereas socioeconomics predicted QoL in standard‐risk ALL. Future efforts should focus on longitudinal studies that describe QoL over time within individual patients.

Identification of paediatric cancer patients with poor quality of life

The primary objective was to describe predictors of physical, emotional and social quality of life (QoL) in children receiving active treatment for cancer. This Canadian multi-institutional cross-sectional study included children with cancer receiving any type of active treatment. The primary caregiver provided information on child physical, emotional and social QoL according to the PedsQL 4.0 Generic Core scales. Between November 2004 and February 2007, 376 families provided the data. In multiple regression, children with acute lymphoblastic leukemia had better physical health (OR: 0.37, 95% CI 0.23, 0.60; P<0.0001) while intensive chemotherapy treatment (OR: 2.34, 95% CI: 1.42, 3.85; P=0.0008) and having a sibling with a chronic condition (OR: 2.53, 95% CI: 1.54, 4.15; P=0.0002) were associated with poor physical QoL. Better emotional health was associated with good prognosis, less intensive chemotherapy treatment and greater household savings, whereas female children and those with a sibling with a chronic condition had poor social QoL. Physical, emotional and social QoL are influenced by demographic, diagnostic and treatment variables. Sibling and household characteristics are associated with QoL. This information will help to identify children at higher risk of poor QoL during treatment for cancer.

Parents of children with cancer: Which factors explain differences in health-related quality of life

Research with parents of children with cancer has identified factors related to their adjustment and coping, but it is not fully understood why some parents do well and others do not. Guided by a stress process model, we examined the interrelationships among a comprehensive set of factors to identify the most important determinants of health‐related quality of life (HRQoL) in parents of children in active treatment for cancer. A cross‐sectional survey of 411 parents (80% response rate) of children receiving cancer treatment in Canada was conducted between November 2004 and February 2007. The following constructs were measured: background and context factors, child characteristics, family‐centered service delivery, caregiver strain, intrapsychic factors, coping/supportive factors and parental HRQoL. The model was evaluated using structural equation modeling. Analysis was stratified by time since diagnosis (i.e., <12 months and ≥12 months). For those within 12 months of their childs diagnosis, family‐centred service provision, caregiver strain, and self‐perception accounted for 58% of the variation in psychosocial health, whereas caregiver strain and social support explained 50% of the variation in physical health. For parents in the >12 month group, caregiving strain was the only factor with a direct relationship with parental psychosocial and physical health, accounting for 66% and 55% of the variance in these constructs, respectively. Our findings reinforce the need for health professionals to be particularly attuned to family caregivers in the early stages of treatment and identify potential areas for interventions to promote parental health.

A novel syndrome of congenital sideroblastic anemia, B-cell immunodeficiency, periodic fevers, and developmental delay (SIFD)

Congenital sideroblastic anemias (CSAs) are a heterogeneous group of inherited disorders identified by pathological erythroid precursors with perinuclear mitochondrial iron deposition in bone marrow. An international collaborative group of physicians and laboratory scientists collated clinical information on cases of CSA lacking known causative mutations, identifying a clinical subgroup of CSA associated with B immunodeficiency, periodic fevers, and development delay. Twelve cases from 10 families were identified. Median age at presentation was 2 months. Anemia at diagnosis was sideroblastic, typically severe (median hemoglobin, 7.1 g/dL) and markedly microcytic (median mean corpuscular volume, 62.0 fL). Clinical course involved recurrent febrile illness and gastrointestinal disturbance, lacking an infective cause. Investigation revealed B-cell lymphopenia (CD19⁺ range, 0.016-0.22 × 10⁹/L) and panhypogammaglobulinemia in most cases. Children displayed developmental delay alongside variable neurodegeneration, seizures, cerebellar abnormalities, sensorineural deafness, and other multisystem features. Most required regular blood transfusion, iron chelation, and intravenous immunoglobulin replacement. Median survival was 48 months, with 7 deaths caused by cardiac or multiorgan failure. One child underwent bone marrow transplantation aged 9 months, with apparent cure of the hematologic and immunologic manifestations. We describe and define a novel CSA and B-cell immunodeficiency syndrome with additional features resembling a mitochondrial cytopathy. The molecular etiology is under investigation.

Clinical and genetic analysis of unclassifiable inherited bone marrow failure syndromes.

OBJECTIVE. Unclassified inherited bone marrow failure syndromes are a heterogeneous group of genetic disorders that represent either new syndromes or atypical clinical courses of known inherited bone marrow failure syndromes. The relative prevalence of the unclassified inherited bone marrow failure syndromes and their characteristics and the clinical and economic challenges that they create have never been studied. METHODS. We analyzed cases of inherited bone marrow failure syndrome in the Canadian Inherited Marrow Failure Registry that were deemed unclassifiable at study entry. RESULTS. From October 2001 to March 2006, 39 of the 162 patients enrolled in the Canadian Inherited Marrow Failure Registry were registered as having unclassified inherited bone marrow failure syndromes. These patients presented at a significantly older age (median: 9 months) than the patients with classified inherited bone marrow failure syndrome (median: 1 month) and had substantial variation in the clinical presentations. The hematologic phenotype, however, was similar to the classified inherited bone marrow failure syndromes and included single- or multiple-lineage cytopenia, severe aplastic anemia, myelodysplasia, and malignancy. Grouping patients according to the affected blood cell lineage(s) and to the presence of associated physical malformations was not always sufficient to characterize a condition, because affected members from several families fit into different phenotypic groups. Compared with the classified inherited bone marrow failure syndromes, the patients with unclassified inherited bone marrow failure syndromes had 3.2 more specific diagnostic tests at 4.5 times higher cost per evaluated patient to attempt to categorize their syndrome. At last follow-up, only 20% of the unclassified inherited bone marrow failure syndromes were ultimately diagnosed with a specific syndrome on the basis of the development of new clinical findings or positive genetic tests. CONCLUSIONS. Unclassified inherited bone marrow failure syndromes are relatively common among the inherited bone marrow failure syndromes and present a major diagnostic and therapeutic dilemma.

Improving diagnostic precision, care and syndrome definitions using comprehensive next-generation sequencing for the inherited bone marrow failure syndromes

Background Phenotypic overlap among the inherited bone marrow failure syndromes (IBMFSs) frequently limits the ability to establish a diagnosis based solely on clinical features. >70 IBMFS genes have been identified, which often renders genetic testing prolonged and costly. Since correct diagnosis, treatment and cancer surveillance often depend on identifying the mutated gene, strategies that enable timely genotyping are essential. Methods To overcome these challenges, we developed a next-generation sequencing assay to analyse a panel of 72 known IBMFS genes. Cases fulfilling the clinical diagnostic criteria of an IBMFS but without identified causal genotypes were included. Results The assay was validated by detecting 52 variants previously found by Sanger sequencing. A total of 158 patients with unknown mutations were studied. Of 75 patients with known IBMFS categories (eg, Fanconi anaemia), 59% had causal mutations. Among 83 patients with unclassified IBMFSs, we found causal mutations and established the diagnosis in 18% of the patients. The assay detected mutant genes that had not previously been reported to be associated with the patient phenotypes. In other cases, the assay led to amendments of diagnoses. In 20% of genotype cases, the results indicated a cancer surveillance programme. Conclusions The novel assay is efficient, accurate and has a major impact on patient care.