Evaluation of bone metabolism in children with acute lymphoblastic leukemia after induction chemotherapy treatment

Methotrexate Chemotherapy Causes Growth Impairments, Vitamin D Deficiency, Bone Loss, and Altered Intestinal Metabolism-Effects of Calcitriol Supplementation

Vitamin D deficiency or insufficiency is prevalent in childhood cancer patients and survivors after chemotherapy; further studies are needed to investigate the underlying aetiology and effectiveness of vitamin D supplementation in preventing chemotherapy-induced bone loss. This study used a rat model of treatment with antimetabolite methotrexate to investigate whether methotrexate chemotherapy causes vitamin D deficiency and if vitamin D supplementation attenuates the resultant bone loss. Methotrexate treatment (five daily injections) decreased serum vitamin D levels (from 52 to <30 ng/mL), reduced body and bone lengthening and tibial trabecular bone volume, and altered intestinal vitamin D metabolism, which was associated with intestinal mucosal damage known to cause malabsorption of nutrients, including dietary vitamin D and calcium. During the early stage after chemotherapy, mRNA expression increased for vitamin D activation enzyme CYP27B1 and for calcium-binding protein TRPV6 in the intestine. During the intestinal healing stage, expression of vitamin D catabolism enzyme CYP24 increased, and that of TRPV6 was normalised. Furthermore, subcutaneous calcitriol supplementation diminished methotrexate-induced bone loss due to its effect suppressing methotrexate-induced increased bone resorption. Thus, in young rats, methotrexate chemotherapy causes vitamin D deficiency, growth impairments, bone loss, and altered intestinal vitamin D metabolism, which are associated with intestinal damage, and vitamin D supplementation inhibits methotrexate-induced bone loss.

[Skeletal manifestations of systemic hematologic disorders]

BACKGROUND

Bone marrow consists of connective tissue and stem cells, which generate blood cells. This includes erythropoiesis, leukopoiesis and thrombopoiesis. Thus, hematologic disorders first affect the bone marrow and secondarily the blood.

METHODS

Bone marrow changes can be sensitively detected using magnetic resonance imaging (MRI) and often represent the initial manifestation of the underlying disease. With longer duration of disease, changes can also be found on X‑ray or computed tomography (CT).

RESULTS

The findings on MRI and X‑ray/CT are often nonspecific and can only be interpreted in the context of clinical information.

CONCLUSION

In the following article, we provide a brief overview of the clinical manifestations and imaging changes to be expected in leukemia, anemia, and chronic myeloproliferative disorders.

Bone health in glucocorticoid-treated childhood acute lymphoblastic leukemia

Glucocorticoids (GCs) are widely used in the treatment of childhood acute lymphoblastic leukemia (ALL), but their long-term use is also associated with bone-related morbidities. Among others, growth deficit, decreased bone mineral density (BMD) and increased fracture rate are well-documented and severely impact quality of life. Unfortunately, no efficient treatment for the management of bone health impairment in patients and survivors is currently available. The overall goal of this review is to discuss the existing data on how GCs impair bone health in pediatric ALL and attempts made to minimize these side effects.

Correlation of Calcium and Magnesium Levels in the Biological Samples of Different Types of Acute Leukemia Children

Acute leukemia (AL) is a common childhood malignancy. It is clinically and morphologically heterogeneous. The present work was intended to estimate the concentration of calcium (Ca) and magnesium (Mg) in serum and whole blood samples of children having AL; 1- to 5- and 6- to 10-year-old children age group was chosen of both genders. Healthy children of the same age group were selected as controls for comparative study. For sample pretreatment, a microwave-assisted acid digestion (MAD) was carried out, to assess the concentration of Ca and Mg in biological samples of AL children. The MAD method was validated by analyzing Clinchek® Control certified samples of whole blood and serum. Ca and Mg were analyzed in the digested samples by flame atomic absorption spectrometry (FAAS). The results showed significantly higher concentration of Ca, whereas lower contents of Mg in the serum and whole blood of AL children in both genders, as compared to healthy subjects. The data provide assistance to physician/clinicians and other professional staffs to investigate the imbalance of minerals in biological samples of AL children.

Correlation of Cadmium and Magnesium in the Blood and Serum Samples of Smokers and Non-Smokers Chronic Leukemia Patients

It was studied that cancer-causing processes are related with the disproportions of essential and toxic elements in body tissues and fluid. The purpose of the current study was to evaluate the levels of magnesium (Mg) and cadmium (Cd) in serum and blood samples of smokers and nonsmokers who have chronic myeloid (CML) and lymphocytic (CLL) leukemia, age ranged 31-50 years. For comparative study, age-matched smokers and nonsmoker males were chosen as controls/referents. The levels of elements in patient were analyzed before any treatment by atomic absorption spectrophotometer, after microwave assisted acid digestion. The validation of the method was done by using certified reference materials of serum and blood samples. The resulted data indicated that the adult male smokers and nonsmokers have two- to fourfold higher levels of Cd in the blood and sera samples as compared to the referents (p < 0.01), whereas two- to threefold lower levels of Mg was found in blood and serum samples of both types of leukemia patients as related to referent values. The resulted data indicates significant negative correlation among Mg and Cd in leukemia patients and smoker referents. Further studies are needed to clarify the role of these elements in pathogenesis of chronic leukemia.

Bone mineral density change during adjuvant chemotherapy in pediatric osteosarcoma

PURPOSE

Osteoporosis is currently receiving particular attention as a sequela in survivors of childhood osteosarcoma. The aim of this study was to evaluate bone mineral density (BMD) changes during methotrexate-based chemotherapy in children and adolescents with osteosarcoma.

METHODS

Nine patients with osteosarcoma were included in this retrospective study and compared with eight healthy controls. BMD of the lumbar spine and unaffected femur neck of patients was serially measured by dual-energy x-ray absorptiometry (DXA) before and just after chemotherapy and compared with controls.

RESULTS

Four patients (44%) showed decreased lumbar spine BMD and seven patients (78%) showed decreased femur neck BMD, while all controls showed increased lumbar and femur BMD (P=0.024 and P=0.023). The femur neck BMD z-scores decreased from -0.49±1.14 to -1.63±1.50 (P=0.032). At the end of therapy, five patients (56%) showed femur neck BMD z-scores below -2.0.

CONCLUSION

The bone metabolism is disturbed during therapy in children with osteosarcoma, resulting in a reduced BMD with respect to healthy controls. Since a reduced BMD predisposes to osteoporosis, specific attention and therapeutic interventions should be considered.

Predictors of bony morbidity in children with acute lymphoblastic leukemia

BACKGROUND

To evaluate the relationship between lumbar spine (LS) bone mineral density (BMD) and patient-, disease-, and therapy-related variables, and to define the risk-factors for fractures in children receiving therapy on Dana-Farber Cancer Institute acute lymphoblastic leukemia (ALL) protocols.

METHODS

Children (≤18 years) diagnosed with ALL during the period 1995-2006, who are in first clinical remission, were included (n = 124). Dual-energy X-ray absorptiometry provided LS-BMD at diagnosis (n = 46) and during continuation therapy. LS-BMD was expressed as Z scores based on local population norms. Regression analyses evaluated the risk of osteopenia (Z-score -1.01 to -1.99, osteoporosis (Z-score -2.00 or less) and fractures.

RESULTS

At diagnosis, 14 0f 46 (30%) patients had osteopenia and 5 (11%) had osteoporosis; whereas, during continuation therapy, 47 of 124 (39.5%) patients had osteopenia, and 10 (8%) had osteoporosis. LS-BMD at diagnosis had a positive linear relationship with LS-BMD during continuation therapy (Pearson correlation coefficient 0.619, P < 0.0001). Multivariable analyses identified age ≥10 years and LS-BMD at diagnosis as independent predictors of LS-BMD during continuation therapy. Twenty-three (18.5%) patients developed fractures. Dexamethasone therapy (OR 3.4, 95% CI 1.31, 7.52, P = 0.01) and lower LS-BMD during the continuation therapy (OR 1.8, 95% CI 1.2, 2.8, P = 0.01) were independent predictors of fracture.

CONCLUSIONS

Older age and lower LS-BMD at diagnosis are predictors of lower LS-BMD during continuation therapy. Dexamethasone and lower LS-BMD during continuation therapy are associated with fractures. Using these variables it is feasible to develop a predictor model to define the risk of bony morbidity in children receiving ALL therapy.

Predictors of bone loss in childhood hematologic malignancies: a prospective study

SUMMARY

Twenty-nine children with malignancies and age, gender-matched controls were prospectively studied over 14 months. Patients had higher parathyroid hormone (PTH) levels and fat mass, lower bone mass, and bone mass increments at follow-up than controls. Lean mass, age at diagnosis, systemic and intrathecal therapy were predictors of bone mass changes on adjusted analyses.

INTRODUCTION

Children with hematologic malignances have low bone mass. We prospectively investigated anthropometric, clinical, and hormonal predictors of changes in bone mass in children receiving cancer therapy.

METHODS

Twenty-nine children, mean age of 9 ± 2.9 years and 32 age and gender-matched controls, were studied. Seven had completed their course 40 ± 22 weeks prior, while 22 were still receiving therapy for 80 ± 28 weeks. Age at diagnosis, calcium intake, exercise activity, systemic corticosteroids in dexamethasone (Dex) dose, and methotrexate (MTX), and intrathecal MTX therapy received within follow-up period were assessed. Routine chemistries, PTH, 25-hydroxy vitamin D (25-OHD), bone remodeling markers, bone mass, and body composition were measured at baseline and 14 months.

RESULTS

Patients had lower exercise activity, sun exposure, and bone markers levels than controls. They had higher PTH levels and fat mass, lower bone mass at the spine, hip, and total body, and lower increments at these sites on follow-up. Predictors of bone mass changes on univariate analyses were: age at diagnosis (R = -0.50 to -0.44, p < 0.05), Dex-MTX doses (R = -0.58 to -0.41, p < 0.05), intrathecal therapy (p < 0.03),% changes in lean mass (R = 0.37 to 0.54, p < 0.04), 25-OHD levels (R = 0.39, p < 0.03), and PTH levels (R = -0.47 to -0.41, p < 0.05). Lean mass, age at diagnosis, systemic and intrathecal therapy were predictors of bone mass changes on adjusted analyses.

CONCLUSION

This study provides insight into the pathophysiology of bone loss in children receiving cancer therapy and possible interventions to optimize their skeletal health.

Skeletal complications after bone marrow transplant in childhood

Childhood cancer survivors are a growing population with special medical needs. It is projected that 66% of these survivors will have at least 1 adverse health effect and 33% will have a severe, chronic, or lethal health disorder. The Institute of Medicine (2003) has recognized the skeletal system to be at risk for long-term complications from treatment for childhood cancer. Bone marrow transplant is frequently used to treat childhood malignancies and is known to cause skeletal complications. Complex mechanisms contribute to skeletal outcomes after bone marrow transplant, all of which can affect optimal physical functioning. Nurses have taken an important role in providing clinical care and conducting research for this population. A thorough understanding of the mechanisms involved in skeletal complications can help the nurse provide state-of-the-art care and design studies to promote optimal results for bone marrow transplant survivors. This article reviews the literature on skeletal complications associated with allogeneic bone marrow transplant and identifies incidence, etiology, symptoms, monitoring, and treatment of specific complications.