The challenge of obesity in paediatric leukaemia treatment: it is not just size that matters

Skeletal muscle and adipose tissue changes in the first phase of treatment of pediatric solid tumors

Body composition is increasingly recognized as an important factor in cancer outcomes. Use of computed tomography (CT) in cancer care provides the opportunity to accurately quantify whole‐body lean and adipose tissues from images at the third lumbar spine. We sought to substantiate the use of routinely captured, single‐slice chest CT images at the thoracic level for evaluation of skeletal muscle, residual lean tissue, and adiposity among pediatric solid tumor patients. We performed a retrospective analysis among children who underwent treatment for a solid tumor at Columbia University Irving Medical Center. Skeletal muscle (SM), residual lean tissue (RLT), and adipose tissue cross‐sectional areas (cm²) were analyzed at diagnosis and at first follow‐up for disease evaluation (6–14 weeks). Imaging analysis was performed utilizing slice‐O‐matic image analysis software. Of the 57 patients identified, 39 had chest CT imaging that included intervertebral level T12‐L1, and 22 also had concurrent imaging at L3. Correlation coefficients between body composition variables at T12‐L1 and L3 were strong (r = 0.93–0.98). Paired t‐test showed a significant decrease in SM (−4.2 ± 8.12, p = 0.003) and RLT (−10.7 ± 28.5, p = 0.025) as well as a trend toward a significant increase in visceral adipose tissue (3.10 ± 9.65, p = 0.052). Univariable analysis demonstrated a significant association between increasing age and increased SM loss (β = −0.496 with SE = 0.194, p = 0.011), and a lack of association between body mass index and body composition changes. We provide the first line of evidence that single‐slice images from routinely obtained chest CT scans provide a simple, readily available mechanism for assessing body composition in pediatric solid tumor patients. Adverse body composition changes were observed, particularly among adolescents and young adults.

Precis: Changes in body composition can be detected via routine CT images in pediatric patients undergoing treatment for solid tumors.

Nutrition during childhood cancer treatment: current understanding and a path for future research

Proper nutritional status during cancer therapy has been recognised as being integral to a variety of health outcome measures, including overall survival, treatment tolerance, and quality of life. The prevalence of malnutrition, defined by WHO as either undernutrition or overnutrition, among children and adolescents with cancer is reported to be as high as 75%. Yet, over the past two decades there have been limited advances in elucidating the underlying pathophysiological drivers of malnutrition in this population. This effect has resulted in a paucity of research aimed at improving nutritional assessment and intervention among this group. This Review presents an in-depth discussion of the role of nutritional status in paediatric cancer care, as well as evolving avenues of investigation that might propel personalised nutrition into a viable reality. Thus, nutritional science might facilitate individualised intervention strategies, and thereby help to optimise clinical outcomes for patients and survivors of childhood cancer.

Inconsistencies in dosage practice in children with overweight or obesity: A retrospective cohort study

Obesity can affect the pharmacokinetics of most drugs, which may result in under- or overdosing if traditional pediatric dosing strategies are used. To investigate currently applied dosage strategies in children with overweight or obesity (overweight/obesity), in a clinical treatment facility. In particular, whether dosing guidelines were available and metrics of body size applied. A retrospective cohort study of 200 patients admitted to the Danish Children's Obesity Clinic. Data were collected from 2007 to 2015. Overweight/obese children 3-18 years were included if they had at least one drug prescription. Overall there were 658 prescriptions, primarily analgesics, psychotropics, asthma medications, and antibiotics. Except for one prescription, guidelines for dosage of overweight/obese children were not available in the clinic. In one prescription of gentamicin, the dose was adjusted by a metric body size. Otherwise dose was predominately prescribed either by total body weight or as fixed dose by age, in accordance with the recommendations of normal weight children. In drugs with a narrow therapeutic interval, we found large interindividual variations in dosing regimens, that is, for gentamicin, paracetamol, and prednisolone. Reduction of dose to the maximum recommended adult dose was common practice, when the dose calculated by total body weight (ie, mg/kg) exceeded this maximum. This study highlights the shortage of dosing guidelines in overweight/obese children. We found a large interindividual variability in dosage regimens, even in drugs with narrow therapeutic intervals. The clinicians rely on "best practice", as evidence-based dosage regimens are missing for many drugs prescribed during childhood.

Pharmacokinetics of two 6-mercaptopurine liquid formulations in children with acute lymphoblastic leukemia

BACKGROUND

A liquid formulation of 6-mercaptopurine (6-MP) was recently approved by the Food and Drug Administration (Purixan®) based on bioavailability (BA) data from healthy adults. We examined the pharmacokinetics (PK) and BA of 6-MP in children with acute lymphoblastic leukemia (ALL) comparing a marketed tablet, two extemporaneously prepared liquid formulations, and data from the approved liquid formulation.

METHODS

Twenty-two children (6-17 years) participated in a randomized two-way, crossover study of two cohorts. Group 1 (n = 11; five males) received a 5 mg/ml liquid formulation and the marketed 50 mg 6-MP tablet on separate occasions, and Group 2 (n = 11; five males) received a 50 mg/ml liquid formulation and the marketed tablet. The usual prescribed 6-MP dose (25-115 mg/m² ) was given after an 8-hr fast. Serial blood samples were collected over 8 hr postdose. Plasma 6-MP concentrations were determined using a good laboratory practice (GLP)-validated liquid chromatography-tandem mass spectrometry method. PK parameters were calculated using noncompartmental analysis and compared within and between cohorts, and thiopurine methyltransferase (TPMT) genotype was analyzed.

RESULTS

No patient had a TPMT genotype reflective of a poor metabolizer phenotype. Comparison of PK parameters between 5 and 50 mg/ml treatments revealed significant differences (P <0.05) in AUC_N (where AUC is area under the curve), C_maxN , and T_max . Comparisons within each group revealed significant differences in AUC_0-∞ and T_max in the 5 mg/ml group.

CONCLUSIONS

Pharmacokinetic profiles of 6-MP established in healthy adults with the approved liquid formulation may not reflect the PK profile in children with ALL. Formulation-specific differences in PK may significantly impact the dose-exposure profile in these children and must be considered.

Pharmacokinetics, pharmacodynamics and pharmacogenetics associated with nonsteroidal anti-inflammatory drugs and opioids in pediatric cancer patients

INTRODUCTION

Advancing appropriate and adequate analgesic pharmacotherapy in pediatric patients with cancer is an area of clinical need. Few studies have been performed to evaluate the selection of an analgesic and appropriate dosing corresponding to analgesic effect among pediatric cancer patients. This review describes information related to pharmacokinetic, pharmacodynamic, and pharmacogenomic (when applicable) considerations for analgesics that are commonly used to manage pain experienced by pediatric patients with cancer. Areas covered: Analgesics commonly used to treat pediatric patients with malignancy patterned after the World Health Organization's 'analgesic ladder' for cancer pain management. Expert opinion: Addressing pain management safely and effectively in pediatric patients with cancer will require advances in both drug development, to increase the armament of analgesics available for children, and our pharmacologic understanding of those analgesics in current use. However, performing the necessary types of studies to develop new analgesics, or gain knowledge of existing therapy, within a population that is relatively small, diverse, and who experience pain originating from a variety of sources, is a tremendous challenge.

[Specificities of prescribing medicines for children]

The vast majority of medicines have been developed for adults. Consequently, the prescribing of medicines for children must take into account their pharmacodynamic characteristics and must be calculated individually according to the degree of prematurity, the age, the weight or body area and the clinical condition. Medication errors are the most common type of medical errors, notably in children, due to dosage errors or prescribtion of inappropriate medicines. The best way to avoid them lies in the use of prescribing software, the involvement of pharmacists in care units, and proper communication between prescribing doctors, caregivers, pharmacists and families.

Selecting the proper pediatric dose: It is more than size that matters

Appropriate pediatric dose selection remains one of the most vexing clinical problems faced by healthcare professionals who are charged to provide medical care to infants and children. While body size does reflect the ontogeny of processes that govern drug disposition, there are extremes of disease that perturb the expected relationships.