Alendronate for steroid-induced osteopenia in children with acute lymphoblastic leukaemia or non-Hodgkin’s lymphoma: results of a pilot study

Identifying causes of balance impairment and exploring sensory contributions to balance in pediatric oncology: A scoping review

PURPOSE

To identify causes of balance impairment in children undergoing treatment for cancer and childhood cancer survivors.

METHODS

A systematic search was performed according to PRISMA guidelines. Studies were included if participants were 0-19 years of age with a current/past diagnosis of cancer, an objective balance measure was reported, and a cause of balance impairment was either stated or implied.

RESULTS

The 64 full text studies included identified balance impairments as sequelae secondary to CNS tumors, and/or as an effect of medical treatment including chemotherapy, radiation, and/or surgery. Cancer treatment can result in damage to the visual, vestibular and/or somatosensory systems which in turn can contribute to balance dysfunction.

CONCLUSIONS

Balance impairments were caused by the cancer itself or the result of medical treatment. Oncology professionals are integral in recognition and treatment of factors affecting balance impairments in childhood cancer; however, further research is needed to identify interventions targeting specific causes of balance impairment.

Broad application prospects of bone turnover markers in pediatrics

BACKGROUND

Bone turnover markers (BTMs) have been studied for application in clinical medicine. However, BTMs in children are challenging, and few studies explore these BTMs in children. The application of BTMs is complicated mainly due to pre-analytical factors, variable reference intervals of age- and sex-related BTMs for adolescents and children in different regions and laboratories. Therefore, laboratory testing of BTMs is critical for understanding pediatric bone development and metabolism, which provides additional information about bone development and diseases.

METHODS

Literature search was conducted using the MeSH term "child" combined with the terms that bone turnover markers such as "osteocalcin," "Procollagen type I N-terminal propeptide," "procollagen type I C-terminal propeptide," "osteocalcin," "N-terminal cross-linked telopeptide," and "C-terminal cross-linked telopeptide," Several databases including Web of Science, Google Scholar, and PubMed were searched to obtain the relevant studies.

RESULTS

BTMs represent the combined effects of skeletal development, growth, and remodeling in children, which can be used in clinical pediatrics to assist in the diagnosis and prognosis of bone metabolic disorders.

CONCLUSION

BTMs are clearly helpful for diagnosis and monitoring of bone growth and development as well as bone metabolic disorders.

Physical and functional performance assessment in pediatric oncology: a systematic review

BACKGROUND

Research indicates reduced physical performance from diagnosis into survivorship of pediatric cancer patients. However, there is no systematic information or guideline available on the methods to assess physical performance and function in this population. The purpose was to systematically compile and describe assessments of physical performance and function in patients and survivors of pediatric cancer, including cardiorespiratory fitness, muscle strength, speed, balance, flexibility, functional mobility, gait and motor performance test batteries.

METHODS

We searched the databases PubMed, SPORTDiscus, and Cochrane Database and performed abstract and full-text selection of 2619 articles according to the Cochrane Handbook of Systematic Reviews. Information on patients characteristics, assessments, information on validity and reliability, and relevant references was extracted.

RESULTS

In summary, 63 different assessments were found in 149 studies including 11639 participants. Most studies evaluated cardiorespiratory fitness and muscle strength with the majority conducted off treatment. Some outcomes (e.g. speed) and diagnoses (e.g. neuroblastoma) were severely underrepresented. With the exception of gait, leukemia patients represented the largest group of individuals tested.

CONCLUSIONS

Insufficient data and patient heterogeneity complicate uniform recommendations for assessments. Our results support researchers and practitioners in selecting appropriate assessment to meet their specific research questions or individual daily practice needs.

IMPACT

This systematic review includes 149 studies and provides a comprehensive summary of 63 assessments to evaluate cardiorespiratory fitness, muscle strength, speed, balance, flexibility, functional mobility, gait or motor performance test batteries in patients and survivors of pediatric cancer. We present the most studied fields within the pediatric cancer population, which are cardiorespiratory fitness and muscle strength, off treatment phase, and leukemia patients. We propose research priorities by identification of subgroups in terms of cancer type, phase of treatment, and outcome of interest that are underrepresented in studies currently available.

Alendronate Improves Bone Mineral Density in Children and Adolescents Perinatally Infected With Human Immunodeficiency Virus With Low Bone Mineral Density for Age

BACKGROUND

Children and adolescents with perinatal human immunodeficiency virus (HIV) infection and with low bone mineral density (BMD) may be at higher risk of osteoporosis and fractures in later life than their uninfected peers. Bisphosphonate therapy has been shown to reduce fractures in adults with osteoporosis, but has not been formally studied in youths living with HIV.

METHODS

Fifty-two children and adolescents (aged 11-24 years) perinatally infected with HIV with low lumbar spine (LS) BMD (Z score < -1.5) were randomized to receive once-weekly alendronate or placebo in a double-blind cross-over study designed to assess the safety and efficacy of 48 and 96 weeks of alendronate in the United States and Brazil. All participants received daily calcium carbonate and vitamin D supplementation and were asked to engage in regular weight-bearing exercise. Safety and efficacy are summarized for the initial 48 weeks of the trial.

RESULTS

Grade 3 or higher abnormal laboratory values, signs, or symptoms developed in 5 of 32 (16%) participants on alendronate and 2 of 18 (11%) on placebo (P > .99). No cases of jaw osteonecrosis, atrial fibrillation, or nonhealing fractures were reported. Mean increases (95% confidence interval) in LS BMD over 48 weeks were significantly larger on alendronate (20% [14%-25%]) than placebo (7% [5%-9%]) (P < .001). Similar improvements were seen for whole body BMD.

CONCLUSIONS

In this small study in children and adolescents perinatally infected with HIV with low LS BMD, 48 weeks of alendronate was well-tolerated, showed no safety concerns, and significantly improved LS and whole body BMD compared to participants on vitamin D/calcium supplementation and exercise alone.

CLINICAL TRIALS REGISTRATION

NCT00921557.

Team approach: Management of osteonecrosis in children with acute lymphoblastic leukemia

With current treatments for acute lymphoblastic leukemia (ALL), the overall prognosis for survival is favorable. Increasing emphasis is placed on recognizing and managing the long-term consequences of ALL and its treatment, particularly involving osteonecrosis. Early osteonecrosis diagnosis and management may improve outcomes and is best accomplished through coordinated teams that may include hematologic oncologists, radiologists, orthopedic surgeons, physical therapists, and the patient and their family. Magnetic resonance imaging is the "gold standard" for diagnosis of early-stage and/or multifocal osteonecrosis. Treatments for osteonecrosis in ALL patients are risk stratified and may include observation, corticosteroid or chemotherapy adjustment, and pharmaceutical or surgical approaches.

Low bone mineral density in children and adolescents with cancer

Maximizing accumulation of bone mass during childhood and adolescence is essential to attaining optimal peak bone mass. Childhood cancer survivors (CCS) have lower bone mineral density (BMD) than the general population. Chemotherapeutic agents including steroids and radiotherapy can affect BMD. Cancer itself, hormonal insufficiency, a poor nutritional state, and a deficit of physical activities during or after treatment also influence BMD in CCS, resulting in failure to achieve appropriate peak bone mass. Low BMD in childhood and adolescence can lead to osteoporosis in adult life and complications such as bone pain, bone deformity, and fractures. Thus, BMD in CCS should be monitored with appropriate intervention. Adequate intake of calcium and vitamin D and an increase in physical activity are recommended. Timely supplements of hormones are needed in some cases. Some publications have reported that bisphosphonate therapies using pamidronate or alendronate were well tolerated in CCS and helped increase BMD.

Bone health in childhood cancer: review of the literature and recommendations for the management of bone health in childhood cancer survivors

In the past decades, new cancer treatment approaches for children and adolescents have led to a decrease in recurrence rates and an increase in long-term survival. Recent studies have focused on the evaluation of the late effects on bone of pediatric cancer-related treatments, such as chemotherapy, radiation and surgery. Treatment of childhood cancer can impair the attainment of peak bone mass, predisposing to premature onset of low bone mineral density, or causing other bone side-effects, such as bone quality impairment or avascular necrosis of bone. Lower bone mineral density and microarchitectural deterioration can persist during adulthood, thereby increasing fracture risk. Overall, long-term follow-up of childhood cancer survivors is essential to define specific groups at higher risk of long-term bone complications, identify unrecognized long-term adverse effects, and improve patient care. Children and adolescents with a cancer history should be carefully monitored, and patients should be informed of possible late complications of their previous medical treatment. The International Osteoporosis Foundation convened a working group to review the bone complications of pediatric cancer survivors, outlining recommendations for the management of bone health, in order to prevent and treat these complications.

Systematic review of the effects of bisphosphonates on bone density and fracture incidence in childhood acute lymphoblastic leukaemia

Skeletal fragility is a common complication of childhood acute lymphoblastic leukaemia (ALL) but the impact of bisphosphonate therapy on bone mass and fracture is unclear. We aim to conduct a systematic review to evaluate the effects of bisphosphonates on bone mineral density (BMD) and fracture incidence in children with ALL.

METHODS

EMBASE, Medline and the Cochrane Library were thoroughly searched by two researchers. Inclusion criteria was any child under the age of 18 years with a diagnosis of ALL, who had received any bisphosphonate treatment and had serial measurements of bone density performed thereafter. All primary research studies of any study design, excluding case reports, were included.

RESULTS

Ten full text papers were identified with two exclusively meeting the inclusion criteria. Both studies administered bisphosphonates to children receiving maintenance chemotherapy for varying durations. Bone density was assessed at regular intervals by dual x-ray absorptiometry (DXA). The majority of participants had an improvement in bone density at the end of each study. However, no size adjustment of DXA data was performed. Limited information on fracture occurrence was provided by one study but did not include routine screening for vertebral fractures.

CONCLUSIONS

This systematic review identified that there is insufficient evidence to support routine use of prophylactic bisphosphonate therapy in childhood ALL for prevention of fracture and improvement of bone mass. Future well-designed clinical trials in those at highest risk of fractures in ALL are now needed.

Efficacy and safety of denosumab therapy for low bone mineral density in childhood cancer survivors: A report of preliminary experience

BACKGROUND

In childhood cancer survivors, low bone mineral density (BMD) is a bone-related consequence. Efficacy of denosumab, an effective therapy for adult patients with osteoporosis, remains unclear in children. This study aimed to investigate denosumab therapy efficacy for low BMD in childhood cancer survivors.

PROCEDURE

Between January 2014 and January 2018, we monitored lumbar BMD of children with cancer using dual-energy X-ray absorptiometry after completing chemotherapy with a 6-month interval. For patients with low BMD, defined as height-adjusted Z-scores of BMD < -1.5 in this study, calcium carbonate and vitamin D supplements were initially administered. When low BMD continued for at least 6 months, denosumab therapy was introduced. Calcium and vitamin D supplementation were continued in patients on denosumab. We investigated BMD change and adverse effects during denosumab therapy.

RESULTS

During the study period, 20 patients received denosumab treatment. Mean height-adjusted Z-score of BMD before denosumab treatment was -2.68 but increased to -2, -1.96, and -1.33 at 0.5, 1, and 1.5 years after denosumab treatment, respectively (P = .012). In addition, hypocalcemia occurred in 40% (8/20) of patients; three patients had hypocalcemic symptoms with numbness in all four limbs. All hypocalcemic patients, except one patient who died due to relapsed leukemia, recovered well after continuous calcium supplementation.

CONCLUSIONS

Denosumab is an effective treatment for low BMD in childhood cancer survivors. However, the complication of hypocalcemia might develop posttreatment.

Bone mineral density in children with acute lymphoblastic leukemia

BACKGROUND

Children with acute lymphoblastic leukemia (ALL) can develop reduced bone mineral density (BMD). However, data from patients who received treatment on a frontline regimen without cranial irradiation are limited, and no genome-wide analysis has been reported.

METHODS

Lumbar BMD was evaluated by quantitative computed tomography at diagnosis, after 120 weeks of continuation therapy, and after 2 years off therapy in pediatric patients with ALL (ages 2-18 years at diagnosis) who were treated on the St. Jude Total XV Protocol. Clinical, pharmacokinetic, and genetic risk factors associated with decreased BMD Z-scores were evaluated.

RESULTS

The median BMD Z-score in 363 patients was 0.06 at diagnosis, declined to -1.08 at week 120, but partly recovered to -0.72 after 2 years off therapy; BMD in patients with low BMD Z-scores at diagnosis remained low after therapy. Older age (≥10 years vs 2-9.9 years at diagnosis; P < .001), a higher BMD Z-score at diagnosis (P = .001), and a greater area under the plasma drug concentration-time curve for dexamethasone in weeks 7 and 8 of continuation therapy (P = .001) were associated with a greater decrease in BMD Z-score from diagnosis to week 120. Single-nucleotide polymorphisms in 2 genes important in osteogenesis and bone mineralization (COL11A1 [reference single-nucleotide polymorphism rs2622849]; P = 2.39 × 10^-7 ] and NELL1 [rs11025915]; P = 4.07 × 10^-6 ]) were associated with a decreased BMD Z-score. NELL1 (P = .003) also was associated with a greater dexamethasone area under the plasma drug concentration-time curve.

CONCLUSIONS

BMD Z-scores decreased during therapy, especially in patients who had clinical, pharmacokinetic, and genetic risk factors. Early recognition of BMD changes and strategies to optimize bone health are essential. Cancer 2018;124:1025-35. © 2017 American Cancer Society.

A randomized controlled trial testing an adherence-optimized Vitamin D regimen to mitigate bone change in adolescents being treated for acute lymphoblastic leukemia

Adolescents with acute lymphoblastic leukemia (ALL) develop osteopenia early in therapy, potentially exacerbated by high rates of concurrent Vitamin D deficiency. We conducted a randomized clinical trial testing a Vitamin D-based intervention to improve Vitamin D status and reduce bone density decline. Poor adherence to home supplementation necessitated a change to directly observed therapy (DOT) with intermittent, high-dose Vitamin D3 randomized versus standard of care (SOC). Compared to SOC, DOT Vitamin D3 successfully increased trough Vitamin 25(OH)D levels (p = .026) with no residual Vitamin D deficiency, 100% adherence to DOT Vitamin D3, and without associated toxicity. However, neither Vitamin D status nor supplementation impacted bone density. Thus, this adherence-optimized intervention is feasible and effective to correct Vitamin D deficiency in adolescents during ALL therapy. Repletion of Vitamin D and calcium alone did not mitigate osteopenia, however, and new, comprehensive approaches are needed to address treatment-associated osteopenia during ALL therapy.

Osteonecrosis in children and adolescents with acute lymphoblastic leukemia: a therapeutic challenge

Osteonecrosis (ON) represents one of the most common and debilitating sequelae of antileukemic treatment in children and adolescents with acute lymphoblastic leukemia (ALL). Systematic screening strategies can focus on early detection and intervention to prevent ON from progressing to stages associated with pain and functional impairment. These strategies hold promise for reducing ON-associated morbidity without the risk of impairing leukemia control. Herein, we critically reviewed clinical data on pharmacological, nonpharmacological/nonsurgical, and surgical (including cellular) treatment options for ON, which are covered in the literature and/or are conceivable based on the supposed underlying ON pathophysiology. Prevention of ON progression is of paramount importance, and attempts seem to be more effective in early (precollapse) disease status than in late-stage (collapse) ON. Based on the results of ongoing prospective magnetic resonance imaging screening studies, which will hopefully identify those patients with a high risk of ON progression and debilitating sequelae, prospective interventional studies are urgently needed. Although there is still a lack of high-quality studies, based on currently available data, core decompression surgery combined with cellular therapies (eg, employing mesenchymal stem cells) appears most promising for preventing joint infraction in children at high risk of developing late-stage ON.

Skeletal Fragility in Children with Chronic Disease

Skeletal fragility associated with underlying childhood chronic disease is a systemic disorder of poor bone growth and reduction in bone turnover which can lead to abnormal bone mass, geometry and microarchitecture. Due to the growth potential unique to children, remarkable bone recovery following a transient threat to the bone can occur if there is concurrent growth. Addressing bone health in these children should focus on improvement in growth, puberty and removing the primary insult. In conditions where there is a little scope for bone recovery and limited residual growth, bone-targeted therapy may need to be considered, even though there is currently limited evidence. The importance of early detection of signs of bone fragility, by active screening for vertebral fracture using newer imaging techniques such as dual-energy X-ray absorptiometry lateral vertebral morphometry, may now be possible. There is currently, a paucity of evidence to support prophylactic use of anti-resorptive therapy. Where poor growth and low bone turnover are seen, the use of growth-promoting therapies and anabolic bone-protective agents may be more physiological and should be evaluated in well-designed trials. Collaborative studies on long-term fracture outcome and well-designed trials of bone-protective therapies are needed and to be encouraged.

Systematic review and meta-analysis: Prevalence and possible causes of vitamin D deficiency and insufficiency in pediatric cancer patients

BACKGROUND AND AIMS

Vitamin D inadequacy is now an internationally recognized health problem and pediatric cancer patients may be at even higher risk than healthy children. We aimed to evaluate primary research to establish the prevalence of vitamin D inadequacy and to explore its possible causes in pediatric cancer patients.

METHODS

Electronic databases were searched (no restriction-Aug 2013) with no language restrictions and keywords related to cancer and vitamin D. We included studies of patients aged <18 years, diagnosed with and treated for cancer and reporting plasma vitamin D status. Evidence was critically appraised employing the CASP tool. Meta-analysis was performed when appropriate.

RESULTS

We included 19 studies, which were mainly of moderate-quality and heterogeneous in the definitions of vitamin D deficiency and insufficiency. The median (range) prevalence of vitamin D deficiency was 14% (0-61.5%) and insufficiency 23% (0-83%). Finally, a significant effect of younger age with vitamin D inadequacy was shown (effect size: -0.132; 95%CI -0.203, -0.060).

CONCLUSION

There is a possibility of a high prevalence of vitamin D inadequacy in pediatric cancer patients, especially older children, urging the need for high-quality population-based longitudinal studies using standard definitions.

Assessment of corticosteroid-induced osteonecrosis in children undergoing chemotherapy for acute lymphoblastic leukemia: a report from the Japanese Childhood Cancer and Leukemia Study Group

Steroid-induced osteonecrosis (ON) is a challenging complication encountered during modern chemotherapy for childhood acute lymphoblastic leukemia (ALL). We retrospectively assessed the incidence of ON and its risk factors in a total of 1095 patients enrolled in 3 consecutive Japanese Children's Cancer and Leukemia Study Group ALL studies (ALL941 [1994 to 2000], n=464; ALL2000 [2000 to 2004], n=305; and ALL2004 [2004 to 2010], n=326). ON was diagnosed in 16 patients, of whom 15 were symptomatic. The cumulative incidence of ON was 0.76% in ALL941, 0.35% in ALL2000, and 3.6% in ALL2004. The incidence of ON in ALL941/2000, in which only prednisolone was administered as a steroid, was significantly lower than that in ALL2004, in which dexamethasone was used as a partial substitute for prednisolone (P<0.01). In ALL2004, sex and age were significantly correlated with the incidence of ON (1.3% in boys vs. 6.7% in girls, P=0.0132; 0.42% for age <10 y vs. 15.6% for age ≥10 y, P<0.0001), suggesting that girls aged 10 years and above are at a greater risk of ON onset. These results indicate that the risk of ON should be considered when administering dexamethasone as part of ALL protocol treatment in girls aged 10 years and above.

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.

Use of bisphosphonates for the treatment of osteonecrosis as a complication of therapy for childhood acute lymphoblastic leukaemia (ALL)

BACKGROUND

Osteonecrosis is a well-recognised complication of current childhood acute lymphoblastic leukaemia (ALL) therapy. There are few studies on the medical management of osteonecrosis in this setting. We studied the therapeutic and radiological effects of oral and intravenous bisphosphonate use compared with standard care as treatment for osteonecrosis in this population.

METHOD

Patients who developed osteonecrosis as a complication of ALL therapy between 1994 and 2007 were treated at a single paediatric institution. Of 17 patients, 9 were commenced on bisphosphonates and 8 treated conservatively. Both groups were observed with time. Pain, analgesic requirement and musculoskeletal function were assessed monthly. Affected joints were radiologically imaged at set intervals. Each scan was graded using an ellipsoid method to give the total volume of osteonecrosis, by blinded radiologic examination.

RESULTS

Three of six patients treated with oral alendronate showed clinical improvement. The three patients that had no improvement were subsequently treated with intravenous pamidronate. All six patients treated with intravenous pamidronate showed clinical improvement. Seven of eight conservatively treated patients deteriorated clinically. All patients demonstrated reduction in the radiological burden of osteonecrosis with time. There was no difference in the rate of reduction between conservative and bisphosphonate arms.

CONCLUSION

Bisphosphonate use, in particular pamidronate, improved pain scores, analgesic requirement and musculoskeletal function in patients with osteonecrosis occurring as a complication of childhood ALL therapy. Objective radiologic benefit of bisphosphonate treatment could not be demonstrated. Risks, benefits and long-term outcome of bisphosphonate use in this population should be addressed in a larger prospective, randomised trial.

Bone mineral density after bone marrow transplantation in childhood: measurement and associations

This study examined the bone mineral density (BMD) of 46 (median age 16.3, 8-29) survivors of autologous and allogeneic bone marrow transplantation (BMT). Areal (g/m2) BMD was acquired with dual energy x-ray absorptiometry and volumetric (g/cm3) BMD values were calculated. Abnormal BMD was identified in 24% (11/46) of survivors with areal measures and 22% (10/46) with volumetric measures. Comparison of areal and volumetric BMD revealed the measures were highly correlated (r = 0.73, p<0.001) but clinical diagnosis of osteopenia/osteoporosis were not consistent. Volumetric z-scores were higher for 7/8 of the survivors who were < 3rd percentile for height. Associations of BMD and body composition and disease and treatment factors were assessed with multiple linear regression. When controlling for other significant associations and cumulative steroid dose, the body composition measure of fat mass index (FMI) was associated with higher volumetric BMD z-scores (CI: 0.006, 0.193; p = 0.037). CNS irradiation (CI: -1.710,-0.200; p = 0.015), age at time of testing (CI: -0.116, -0.024; p = 0.004) and female sex (CI: -1.375, -0.155; p = 0.015) were associated with lower volumetric BMD z-scores.

CONCLUSIONS

Childhood BMT survivors are at risk for diminished BMD. Areal and volumetric DEXA derived measures of BMD are highly correlated and volumetric measures may correct for underestimation of BMD in BMT survivors who are small for age. Survivors who received CNS irradiation, are older and female may be at greater risk for diminished BMD while fat mass is associated with higher BMD in childhood BMT survivors.

Treatment of osteoporosis/osteopenia in pediatric leukemia and lymphoma

OBJECTIVE

To evaluate the efficacy and safety of various treatment options for osteopenia and osteoporosis secondary to cancer treatment in pediatric patients undergoing cancer therapy.

DATA SOURCES

A systematic search of PubMed (1949-November 2008) and International Pharmaceutical Abstracts (to November 2008) was conducted using the following search terms: osteoporosis, osteopenia, pediatrics, cancer, neoplasms, chemotherapy, bisphosphonates, calcium, vitamin D, calcitonin, and physical therapy.

STUDY SELECTION AND DATA EXTRACTION

All prospective studies that evaluated various osteoporosis treatment options in pediatric patients undergoing chemotherapy were included. Results from studies evaluating bisphosphonates and other treatments in children with osteoporosis due to other causes were also included if important safety and efficacy data were provided. Most commonly reported primary efficacy endpoints included comparisons of bone density parameters measured before and after treatment.

DATA SYNTHESIS

Four clinical studies and 2 case reports describing treatment with bisphosphonates, specifically alendronate and pamidronate, for osteoporosis or osteopenia in pediatric cancer patients were identified. Results from the trials showed that these medications were efficacious in reducing bone mineral density loss during cancer therapy and were well tolerated in this special population. Primary efficacy endpoints included improvements in Z-scores measured by dual-energy X-ray absorptiometry scans. The most commonly reported adverse effects included hypocalcemia, mild stomach upset, and infusion-related hyperpyrexia. Four additional clinical trials involving the treatment of osteoporosis or osteopenia in children and adolescents who developed bone degeneration after chronic steroid therapy are also included. In these trials, treatment options such as calcitonin, and calcium and vitamin D supplementation were also shown to be beneficial.

CONCLUSIONS

The clinical trials published to date are limited to only a few conducted in small populations of patients diagnosed with lymphoblastic leukemia or non-Hodgkin's lymphoma. However, alendronate and pamidronate both appeared to be effective options in improving bone mineral density scores with minimal adverse effects.

Effects of alendronate and pamidronate on cultured rat metatarsal bones: failure to prevent dexamethasone-induced growth retardation

Bisphosphonates are widely used anti-resorptive drugs in the adult population. In children, their use has mainly been limited to patients with osteogenesis imperfecta. However, the powerful effects of bisphosphonates on bone turnover have raised concern about their long-term effects on the growing skeleton. We aimed to study the effects of two commonly used bisphosphonates, alendronate (Aln) and pamidronate (Pam) on normal bone growth as well as their potential to prevent glucocorticoid-induced growth retardation. Effects on bone growth were studied in fetal rat metatarsal bones (day E20) that were cultured for 5-47 days and measured every 2-7 days. Cellular mechanisms were investigated in metatarsal bones and also in the human chondrocytic cell line HCS-2/8. Chondrocyte viability (WST-1), proliferation (BrdU incorporation), differentiation (collagen type X immunohistochemistry) and apoptosis (TUNEL and Cell Death ELISA) were determined. At a clinically relevant concentration of bisphosphonates (1 microM), metatarsal bone growth was stimulated by both Aln (p<0.001 for length and p<0.05 for width) and Pam (p<0.05 for both length and width) from day 19 of culture. The growth-stimulatory effect was associated with increased chondrocyte proliferation (+21% with Aln and +24% with Pam), while cell differentiation and apoptosis were not affected. Despite the finding that both Aln and Pam (1 muM) rescued HCS-2/8 cells from undergoing dexamethasone-induced apoptosis, neither of them was able to prevent dexamethasone-induced growth retardation of fetal rat metatarsal bones. Aln and Pam have the capacity to stimulate the growth of cultured fetal rat metatarsal bones; an effect associated with increased proliferation of growth plate chondrocytes. Our experimental data suggest that bisphosphonates are ineffective in preventing glucocorticoid-induced growth retardation. Nevertheless, based on our in vitro data, both Aln and Pam appear safe to use in growing children, at least with regard to their effects on linear bone growth.

Osteonecrosis in children and adolescents with cancer

Osteonecrosis is recognized increasingly as a complication of the treatment of cancer in young people, especially those with acute lymphoblastic leukemia and non-Hodgkin lymphoma, reflecting a probable pathogenetic role of steroid therapy. Children >/=10 years of age and Whites are at particular risk, and genetic predispositions have been identified. The disorder affects weight-bearing joints predominantly. It is commonly bilateral and multi-articular. Treatment options include both surgical and non-surgical interventions.

Assessing mineral metabolism in children using stable isotopes

Mineral metabolism may be altered in children with acute or chronic illnesses. The effects may be short term, such as hypomagnesemia associated with chemotherapy, or long-term, such as loss of bone mineral mass after steroid use. Understanding the causes, consequences, and potential therapies for mineral disorders is enhanced by understanding the absorption, body utilization, and turnover of these minerals. These assessments can now be done safely and readily using non-radioactive, stable isotopes which are available for calcium, zinc, magnesium, and iron. The methods for measurement of mineral absorption and kinetics (turnover) are well established, especially for calcium, and have been tested in every age group. Few studies, however, have been performed in children with acute or chronic illnesses such as cancer. Isotope dosing and infusion protocols are minimally invasive and protocols require small blood or urine volumes. Mineral absorption can be assessed without collecting fecal samples. Kinetics are assessed with blood and urine collections, usually over 5-10 days. Increased use of these techniques may be important in medical and nutritional assessment as well as in the management of pediatric oncology patients.

Osteoporosis in children with cancer

As increasing numbers of childhood cancer patients are surviving, the long-term complications of the disease and its treatment have become ever more increasingly important. Reduced bone mineral density and increased fracture risk have been reported during and after treatment of children with cancer. The causes of osteoporosis are multifactorial. Among others, the disease itself, chemotherapy, irradiation and genetic susceptibility play a role. Bone mineral density in later life depends largely on the peak bone mass achieved in adolescence or young adulthood. Therefore, optimizing peak bone mass is of clinical importance. Preventive and therapeutic strategies, such as calcium and vitamin D supplementation, physical activity and bisphosphonates, are considered.

Low bone mass in children with malignant lymphoma

The aim of this work was to study the effect of disease process on bone mass and calcium homeo-stasis in children with malignant lymphoma at diagnosis, 3 months after starting chemotherapy, and after 1 year. Evaluation of lumber vertebrae (L2-L4) bone mineral density using dual-energy X-ray absorptiometry and calcium homeostasis parameters and bone turnover biochemical markers (serum osteocalcin and urinary deoxypyridinoline) had been assayed in twenty lymphoma patients at presentation and after treatment. Low bone mass for chronological age was observed in 4 patients (20%) at diagnosis and persisted after 3 months and 1 year. Parathyroid hormone level demonstrated no differences between children with lymphoma at different stages of therapy and controls, while 25(OH) D(3) was significantly lower in lymphoma patients at different stages of therapy as compared to controls (p < .001). Osteocalcin was significantly lower in lymphoma patients at different stages of therapy. Deoxypyridinoline showed only significant higher values after 3 months of therapy compared to controls (p = .01). In conclusion, low bone mass was observed in children with lymphoma and is related to decreased osteoblastic activity and decreased mineralization of bone.

Bisphosphonate therapy for children and adolescents with secondary osteoporosis

BACKGROUND

Children with chronic illnesses are at increased risk for reductions in bone strength and subsequent fractures (osteoporosis), either due to the impact of the underlying condition on skeletal development or due to the osteotoxic effect of medications (e.g., glucocorticoids) used to treat the chronic illness. Bisphosphonates are being administered with increasing frequency to children with secondary osteoporosis; however, the efficacy and harm of these agents remains unclear.

OBJECTIVES

To examine the efficacy and harm of bisphosphonate therapy in the treatment and prevention of secondary osteoporosis in children and adolescents.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (Issue 4, 2006), MEDLINE, EMBASE, CINAHL and ISI Web of Science (inception-December 2006). Further literature was identified through expert contact, key author searches, scanning reference lists of included studies, and contacting bisphosphonate manufacturers.

SELECTION CRITERIA

Randomized, quasi-randomized, controlled clinical trials, cohort, and case controls of bisphosphonate(s) in children 0-18 years of age with at least one low-trauma fracture event or reductions in bone mineral density in the context of secondary osteoporosis.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed quality. Case series were used for supplemental harms-related data.

MAIN RESULTS

Six RCTs, two CCTs, and one prospective cohort (n=281 children) were included and classified into osteoporosis due to: 1) neuromuscular conditions (one RCT) and 2) chronic illness (five RCTs, two CCTs, one cohort). Bisphosphonates examined were oral alendronate, clodronate, and intravenous (IV) pamidronate. Study quality varied. Harms data from 23 case series (n=241 children) were used. Heterogeneity precluded statistically combining the results. Percent change or Z-score change in lumbar spine areal BMD from baseline were consistently reported. Two studies carried out between-group analyses; one showed no significant difference (using oral alendronate in anorexia nervosa) while the other demonstrated a treatment effect on lumbar spine with IV pamidronate in burn patients. Frequently reported harms included the acute phase reaction, followed by gastrointestinal complaints, and bone/muscle pain.

AUTHORS' CONCLUSIONS

The results justify further evaluation of bisphosphonates among children with secondary osteoporosis. However, the evidence does not support bisphosphonates as standard therapy. Short-term (3 years or less) bisphosphonate use appears to be well-tolerated. An accepted criterion for osteoporosis in children, a standardized approach to BMD reporting, and examining functional bone health outcomes (e.g., fracture rates) will allow for appropriate comparisons across studies.

Bisphosphonate therapy for reduced bone mineral density during treatment of acute lymphoblastic leukemia in childhood and adolescence: a report of preliminary experience

BACKGROUND

Osteopenia is a common consequence of the treatment of acute lymphoblastic leukemia (ALL) in children and adolescents, due predominantly to glucocorticosteroid therapy. The pathogenesis relates to an imbalance of resorption over formation of bone.

METHODS

Alendronate (Fosamax), an inhibitor of osteoclastic bone resorption, was administered for at least 6 months to 15 children with ALL during maintenance chemotherapy, after the diagnosis of osteopenia/osteoporosis by dual energy x-ray absorptiometry. The height velocity was also measured during the administration of alendronate and again 2 years later.

RESULTS

Areal bone mineral density Z scores of the lumbar spine had a median value of -1.32 before administration of alendronate and a median gain of +0.64, with 14/15 children showing improvement. There was no adverse effect of alendronate on height velocity, and the drug was well tolerated with no short-term toxicity.

CONCLUSIONS

This preliminary experience suggests a potential value in the use of alendronate for the treatment of osteopenia/osteoporosis in children with ALL and points to the need for a randomized controlled trial of this intervention.

Bone mineral status after treatment of malignant lymphoma in childhood and adolescence

The relationship between bone mineral mass and cumulative dose of corticosteroids (CDC) was investigated in 42 children and adolescents treated for Hodgkin disease (HD; n = 22) and non-Hodgkin lymphoma (NHL; n = 20). The median age at the time of the study was 24.1 years for HD survivors and 14.1 years for NHL survivors. Dual-energy X-ray absorptiometry [bone mineral density of the lumbar spine (LS-BMD) expressed as Z-scores] and peripheral quantitative computed tomography at the distal radius [trabecular volumetric BMD (vBMD-trab)] were undertaken. Osteopenia (Z-score < -1.00) was found in 9/22 patients with HD and 10/20 with NHL, while 34% (HD = 6, NHL = 8) had a vBMD-trab below the normal range. The CDC correlated inversely with LS-BMD Z-score (r =-0.41, P = 0.007). There was a statistically significantly higher vBMD-trab in patients who received low (1-4 g/m(2)) compared with high (>or=20 g/m(2)) CDC (P = 0.031). Treatment of malignant lymphoma with high CDC is a risk factor for development of osteopenia.

Osteopenia and cancer in children and adolescents: the fragility of success

The attainment of a satisfactory peak bone mass, which is accomplished largely by the end of adolescence, is the best protection against excessive bone mineral loss in late adulthood. Factors that influence this process include age, race, sex, body size, pubertal status, diet, physical activity, and other lifestyle elements. Cancer and its treatment in children and teenagers adversely impact bone mineralization. In particular, chemotherapy (especially glucocorticosteroids and methotrexate) and cranial irradiation (apparently by reducing growth hormone secretion and by causing hypogonadotropic hypogonadism) interfere with normal bone turnover. Resorption often exceeds formation, resulting in net bone mineral loss and providing a rational basis for the use of antiresorptive drugs. Such osteopenia may be symptomatic, with pain and abnormal gait, and increases the risk of fractures several fold. The disorder is compounded by reduced physical activity, so programs to reduce this deficit are of measurable benefit. All of those engaged in the care of children and adolescents with cancer have an opportunity to improve the bone health of these young people and to limit their risk of developing osteoporosis and fragility fractures in adult life.

Osteonecrosis in children and adolescents with cancer - an adverse effect of systemic therapy

Osteonecrosis (ON) is recognised increasingly as a complication of the treatment of cancer in children and adolescents. It is especially prevalent among survivors of acute lymphoblastic leukaemia and non-Hodgkin lymphoma, in whom as many as 1/3 may be affected, likely reflecting the cumulative exposure to glucocorticosteroid therapy. The pathogenesis is complex and includes suppression of bone formation, expansion of the intra-medullary lipocyte compartment and a direct effect on nutrient arteries. Children > or =10 years of age are at particular risk and the disorder is substantially more common in Whites than in Blacks. Genetic predispositions have been identified. ON is often multi-articular and bilateral, affecting weight-bearing joints predominantly. Surgical management options are of concern in young growing subjects, although injection of autologous marrow into affected sites offers promising results. Other novel approaches include the use of anti-resorptive drugs and strategies for prevention, such as with lipid-lowering agents, are being explored.

A nutrition odyssey: knowledge discovery, translation, and outreach. 2006 Ryley-Jeffs Memorial Lecture

BACKGROUND

The 21st-century model of health research is founded on a broad base of multidisciplinary research that is expeditiously and effectively translated into evidence-based practice, education, policy, and advocacy. The key objective is to improve the health of populations. DIETITIANS' ROLES: Dietitians, whether they are working in clinical or public health nutrition or food science, have a vital role to play in this paradigm of health research. As dietitians' roles have evolved beyond the traditional ones into subspecialties including epidemiology, nutrigenomics, functional foods, nutraceuticals, toxicology, natural health products, and multidisciplinary research, the need for advanced training in subspecialty fields has become essential.

OPPORTUNITIES

A dietetics background is an excellent foundation upon which to develop a research career in one of these new areas of nutrition. Opportunities for personnel awards and research funding targeted at nutrition clinician-scientists and other nutrition subspecialists have grown tremendously in recent years.

CONCLUSION

The information in this paper is intended to inspire dietitians seeking advanced academic training in one of the new exciting avenues for a career in nutrition. These avenues will permit dietitians to contribute to knowledge discovery, translation, and outreach to improve the nutritional status and health of populations in Canada and globally.