Bone mineral density deficits and fractures in survivors of childhood cancer

Dose-Related Effect of Chemotherapy on Bone Mineral Density Among Pediatric Acute Lymphoblastic Leukemia Survivors

OBJECTIVES

Reduced bone mineral density (BMD) can negatively affect lifelong skeletal health by -increasing the risk for developing osteopenia and osteoporosis. This study evaluated the relationship between BMD and cumulative doses of intravenous (IV) methotrexate (MTX) and glucocorticoids in pediatric acute lymphoblastic leukemia (ALL) survivors. The association between BMD and vitamin D concentrations measured at the time of entry into the long-term follow-up program was also assessed.

METHODS

This retrospective study included pediatric ALL survivors who had received a dual-energy X-ray absorptiometry (DXA) scan after the end of therapy (EOT) or within the 6 months prior to the EOT. Low/-intermediate and high cumulative IV MTX doses were defined as doses less than 20,000 mg/m2 and -greater than or equal to 20,000 mg/m2, respectively. Descriptive statistics, Student t test, and linear -regression were used to analyze the data.

RESULTS

A total of 62 patients, with 34 patients in the low/intermediate and 28 patients in the high -cumulative IV MTX dose groups, were analyzed. The median time from EOT to DXA scan was 2.3 years. The mean DXA lumbar spine z score was significantly lower in the high cumulative IV MTX dose group -compared with the low/intermediate dose group (-0.86 vs -0.14; p = 0.008). Cumulative glucocorticoid doses and vitamin D concentrations were not associated with BMD.

CONCLUSIONS

Pediatric patients who had received cumulative IV MTX doses of greater than or equal to 20,000 mg/m2 during their ALL treatment had lower BMD than those who had received lower cumulative doses.

Contributing factors to well-being in a sample of long-term survivors of childhood acute lymphoblastic leukemia: the role of social support in emotional regulation

Objectives: To understand why some long-term childhood cancer survivors experience positive adjustment in the long run,[Q1] this study aimed to (1) explore associations between well-being, health status, social support, and emotion regulation (ER) strategies in a cohort of long-term childhood lymphoblastic leukemia (cALL) survivors, (2) identify the individual contribution of each ER strategy to well-being (3) and their interaction with social support. Methods: We used data from 92 participants from the PETALE cohort (51% female, aged 24 ± 7 years). Measures included well-being (WHO-5), health status (15D), social support (SSQ-6), cognitive reappraisal and expressive suppression (ERQ), and emotional processing and expression (EAC). We modeled the odds of high well-being adjusting for health status in logistic regressions and explored the moderating role of social support with bootstrap techniques. Independent of clinical history, high well-being was associated with better health status, higher social support, more frequent use of cognitive reappraisal and emotional processing. Results: We found a main contribution of emotional processing to well-being (OR = 2.12, 95% CI = 1.09-5.37). The interaction between low suppression and high social support was significant (OR = .40, 95% CI = .13-.79). Probabilities for high well-being were 96% when expressive suppression was low and social support was high. Results suggest approaching one's own emotions may contribute to well-being in long-term childhood cancer survivors. Clinical implications: Combining curbing emotional suppression with promoting supportive social environment could be a promising target for future supportive care interventions in survivors.

Determinants of bone parameters in young paediatric cancer survivors: the iBoneFIT project

BACKGROUND

Bone health is remarkably affected by endocrine side effects due to paediatric cancer treatments and the disease itself. We aimed to provide novel insights into the contribution of independent predictors of bone health in young paediatric cancer survivors.

METHODS

This cross-sectional multicentre study was carried out within the iBoneFIT framework in which 116 young paediatric cancer survivors (12.1 ± 3.3 years old; 43% female) were recruited. The independent predictors were sex, years from peak height velocity (PHV), time from treatment completion, radiotherapy exposure, region-specific lean and fat mass, musculoskeletal fitness, moderate-vigorous physical activity and past bone-specific physical activity.

RESULTS

Region-specific lean mass was the strongest significant predictor of most areal bone mineral density (aBMD), all hip geometry parameters and Trabecular Bone Score (β = 0.400-0.775, p ≤ 0.05). Years from PHV was positively associated with total body less head, legs and arms aBMD, and time from treatment completion was also positively associated with total hip and femoral neck aBMD parameters and narrow neck cross-sectional area (β = 0.327-0.398, p ≤ 0.05; β = 0.135-0.221, p ≤ 0.05), respectively.

CONCLUSION

Region-specific lean mass was consistently the most important positive determinant of all bone parameters, except for total hip aBMD, all Hip Structural Analysis parameters and Trabecular Bone Score.

IMPACT

The findings of this study indicate that region-specific lean mass is consistently the most important positive determinant of bone health in young paediatric cancer survivors. Randomised clinical trials focused on improving bone parameters of this population should target at region-specific lean mass due to the site-specific adaptations of the skeleton to external loading following paediatric cancer treatment. After paediatric cancer diagnosis, years from peak height velocity (somatic maturity) is critical for bone development.

Effect of a 1-year physical activity intervention on cardiovascular health in long-term childhood cancer survivors-a randomised controlled trial (SURfit)

BACKGROUND

This randomised controlled trial (RCT) assessed the effect of a 1-year, partially supervised, physical activity (PA) intervention on a cardiovascular disease (CVD) risk score in adult survivors of childhood cancer.

METHODS

We included childhood cancer survivors ≥16 y at enrolment, <16 y at diagnosis and ≥5 y in remission. The intervention group was asked to perform an additional ≥2.5 h of intense physical activity/week, controls continued exercise as usual; assessments were performed at baseline, 6 months (T6) and 12 months (T12). The primary endpoint was change in a CVD risk score (average z-score of waist circumference, blood pressure, fasting glucose, inverted high-density lipoprotein cholesterol, triglycerides, and inverted cardiorespiratory fitness) from baseline to T12. We performed intention-to-treat (ITT, primary) and 3 per protocol analyses.

RESULTS

We randomised 151 survivors (44% females, 30.4 ± 8.6 years). We found a significant and robust reduction of the CVD risk score in the intervention compared to the control group at T6 and T12 across all analyses; with a difference in the reduction of the CVD risk z-score of -0.18 (95% confidence interval -0.29 to -0.06, P = 0.003) at T12 in favour of the intervention group (ITT analysis).

CONCLUSIONS

This RCT showed that a long-term PA intervention can reduce CVD risk in long-term survivors of childhood cancer.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT02730767.

OPG/RANK/RANKL Axis in Egyptian Children With Acute Lymphoblastic Leukemia After Maintenance Therapy: Relationship to Bone Mineral and Vitamin D Status

Policies to maximize peak bone mass in survivor's children of acute lymphoblastic leukemia (ALL) have been recognized as a priority area for research. The present study aimed to evaluate the relationship between osteoprotegerin (OPG)/receptor activator of nuclear factor kappa-B (RANK)/RANK ligand (RANKL) axis, vitamin D status, and serum magnesium in ALL survivors. Sixty ALL survivors treated with chemotherapy and 60 age and sex-matched controls were included. Vitamin D and parathyroid hormone, RANK, RANKL, and OPG levels were immunoassayed, in addition to serum calcium, phosphorus, magnesium levels, and alkaline phosphatase activity assessment. Furthermore, standard anthropometric measurement, history of fractures since treatment and clinical assessment were recorded. History of bone fractures after the start of therapy was detected in 17 ALL subjects (28.33%). Significantly lower vitamin D, magnesium, calcium, and OPG levels, meanwhile, significantly higher serum parathyroid hormone, RANK, and RANKL levels were detected in survivors compared with the control group. Vitamin D level was significantly positively correlated with magnesium, calcium, and OPG levels. Meanwhile, negatively correlated with RANK and RANKL levels. ALL survivors had a high prevalence of impaired vitamin D status, decreased Mg, and altered OPG/RANK/RANKL axis with impaired bone remodeling. The results herein may open the door for new interventional actions in ALL survivors to protect against bone resorption.

Inference for set-based effects in genetic association studies with interval-censored outcomes

The rapid acceleration of genetic data collection in biomedical settings has recently resulted in the rise of genetic compendiums filled with rich longitudinal disease data. One common feature of these data sets is their plethora of interval-censored outcomes. However, very few tools are available for the analysis of genetic data sets with interval-censored outcomes, and in particular, there is a lack of methodology available for set-based inference. Set-based inference is used to associate a gene, biological pathway, or other genetic construct with outcomes and is one of the most popular strategies in genetics research. This work develops three such tests for interval-censored settings beginning with a variance components test for interval-censored outcomes, the interval-censored sequence kernel association test (ICSKAT). We also provide the interval-censored version of the Burden test, and then we integrate ICSKAT and Burden to construct the interval censored sequence kernel association test-optimal (ICSKATO) combination. These tests unlock set-based analysis of interval-censored data sets with analogs of three highly popular set-based tools commonly applied to continuous and binary outcomes. Simulation studies illustrate the advantages of the developed methods over ad hoc alternatives, including protection of the type I error rate at very low levels and increased power. The proposed approaches are applied to the investigation that motivated this study, an examination of the genes associated with bone mineral density deficiency and fracture risk.

Effect of exercise on bone health in children and adolescents with cancer during and after oncological treatment: A systematic review and meta-analysis

Background: Although regular physical activity and exercise programs might improve bone health caused by oncological treatment and the disease itself, it remains unknown the pooled effect of exercise interventions following frequency, intensity, time and type prescriptions.

Objective: This systematic review and meta-analysis aimed to synthesise evidence regarding the effectiveness of exercise interventions on bone health in children and adolescents with cancer during and after oncological treatment.

Methods: A systematic search was conducted in the MEDLINE (via PubMed), Web of Science and Scopus databases from November 2021 to January 2022. Randomised controlled trials (RCTs) and non-RCTs reporting pre-post changes of the effectiveness of exercise interventions on DXA-measured bone parameters in young population (1–19 years) during or after oncological treatment were included. Pooled (ESs) and 95% confidence intervals (95%CIs) were calculated. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed.

Results: A total of eight trials with 341 participants were included. The meta-analyses did not reveal a statistically significant increase in whole body areal bone mineral density (ES = 0.10; 95%CI: −0.14, 0.34), lumbar spine (ES = 0.03; 95%CI: −0.21, 0.26) or femoral neck (ES = 0.10; 95%CI: −0.37, 0.56). Similarly, during the oncological treatment phase the ES was 0.04 (95%CI: −0.17, 0.25) and after the ES was 0.07 (95%CI: −0.20, 0.33).

Conclusion: To date, exercise interventions have been inappropriate and therefore, ineffective to illustrate any beneficial effect on bone health in children and adolescents with cancer during and after oncological treatment.

Systematic Review Registration: PROSPERO registration number: CRD42022310876

Prevalence of low bone mineral density and risk of fractures in osteosarcoma and Ewing's sarcoma survivors: A scoping review

Background

The clinical outcomes of patients with pediatric cancer have significantly improved over the past few decades. However, the treatments are often highly intensive and can advertently pose a risk for developing various health conditions, including bone mass loss and fragility fractures. Since patients with bone malignancies, such as osteosarcoma (OS) and Ewing's sarcoma (ES), require musculoskeletal surgery as well as chemotherapy, OS/ES survivors are potentially at even greater risk of developing these musculoskeletal conditions than those with other types of cancer. However, these issues in OS/ES survivors are often overlooked by clinicians treating childhood cancers. Thus, this scoping review was designed and conducted to better understand the bone health conditions in OS/ES survivors.

Design

We conducted a literature search and included the studies that describe bone mineral density in association with bone health in OS/ES survivors for analysis. Data regarding patients' demographic, diagnosis, bone mineral density, laboratory examinations, and incidence of fractures were extracted and evaluated.

Results

We found that almost half of OS/ES survivors have bone mass deficit and that several factors (such as a frailer physique and younger age at diagnosis) are potentially associated with low bone mass in OS/ES survivors. On the other hand, due to a paucity of information currently available, we could not determine whether long-term OS/ES survivors would ultimately regain bone mass or be at a greater risk of fragility fractures.

Conclusions

This scoping review reveals a previously unappreciated knowledge gap in our understanding of bone health conditions in OS/ES survivors and raises awareness among clinicians and care providers of this condition that OS/ES patients may encounter after successful treatment.

Aging and Bone Metabolism

Changes in bone architecture and metabolism with aging increase the likelihood of osteoporosis and fracture. Age-onset osteoporosis is multifactorial, with contributory extrinsic and intrinsic factors including certain medical problems, specific prescription drugs, estrogen loss, secondary hyperparathyroidism, microenvironmental and cellular alterations in bone tissue, and mechanical unloading or immobilization. At the histological level, there are changes in trabecular and cortical bone as well as marrow cellularity, lineage switching of mesenchymal stem cells to an adipogenic fate, inadequate transduction of signals during skeletal loading, and predisposition toward senescent cell accumulation with production of a senescence-associated secretory phenotype. Cumulatively, these changes result in bone remodeling abnormalities that over time cause net bone loss typically seen in older adults. Age-related osteoporosis is a geriatric syndrome due to the multiple etiologies that converge upon the skeleton to produce the ultimate phenotypic changes that manifest as bone fragility. Bone tissue is dynamic but with tendencies toward poor osteoblastic bone formation and relative osteoclastic bone resorption with aging. Interactions with other aging physiologic systems, such as muscle, may also confer detrimental effects on the aging skeleton. Conversely, individuals who maintain their BMD experience a lower risk of fractures, disability, and mortality, suggesting that this phenotype may be a marker of successful aging. © 2023 American Physiological Society. Compr Physiol 13:4355-4386, 2023.

Effect of a physical activity intervention on lower body bone health in childhood cancer survivors: A randomized controlled trial (SURfit)

It remains controversial whether physical activity promotes bone health in childhood cancer survivors (CCS). We aimed to assess the effect of a one-year general exercise intervention on lower body bone parameters of CCS. CCS ≥16 years at enrollment, <16 years at diagnosis and ≥5 years in remission were identified from the national Childhood Cancer Registry. Participants randomized to the intervention group were asked to perform an additional ≥2.5 hours of intense physical activity/week, controls continued exercise as usual. Bone health was assessed as a secondary trial endpoint at baseline and after 12-months. We measured tibia bone mineral density (BMD) and morphology by peripheral quantitative computed tomography and lumbar spine, hip and femoral neck BMD by dual-energy x-ray absorptiometry. We performed intention-to-treat, per protocol, and an explorative subgroup analyses looking at low BMD using multiple linear regressions. One hundred fifty-one survivors (44% females, 7.5 ± 4.9 years at diagnosis, 30.4 ± 8.6 years at baseline) were included. Intention-to-treat analysis revealed no differences in changes between the intervention and control group. Per protocol analyses showed evidence for an improvement in femoral neck and trabecular BMD between 1.5% and 1.8% more in participants being compliant with the exercise program. Trabecular BMD increased 2.8% more in survivors of the intervention group with BMD z-score ≤-1 compared to those starting at z-score >-1. A nonstandardized personalized exercise programs might not be specific enough to promote bone health in CCS, although those compliant and those most in need may benefit. Future trials should include bone stimulating exercise programs targeting risk groups with reduced bone health and motivational features to maximize compliance.

Transition of young adults with metabolic bone diseases to adult care

As more accurate diagnostic tools and targeted therapies become increasingly available for pediatric metabolic bone diseases, affected children have a better prognosis and significantly longer lifespan. With this potential for fulfilling lives as adults comes the need for dedicated transition and intentional care of these patients as adults. Much work has gone into improving the transitions of medically fragile children into adulthood, encompassing endocrinologic conditions like type 1 diabetes mellitus and congenital adrenal hyperplasia. However, there are gaps in the literature regarding similar guidance concerning metabolic bone conditions. This article intends to provide a brief review of research and guidelines for transitions of care more generally, followed by a more detailed treatment of bone disorders specifically. Considerations for such transitions include final adult height, fertility, fetal risk, heritability, and access to appropriately identified specialists. A nutrient-dense diet, optimal mobility, and adequate vitamin D stores are protective factors for these conditions. Primary bone disorders include hypophosphatasia, X-linked hypophosphatemic rickets, and osteogenesis imperfecta. Metabolic bone disease can also develop secondarily as a sequela of such diverse exposures as hypogonadism, a history of eating disorder, and cancer treatment. This article synthesizes research by experts of these specific disorders to describe what is known in this field of transition medicine for metabolic bone diseases as well as unanswered questions. The long-term objective is to develop and implement strategies for successful transitions for all patients affected by these various conditions.

Safety and Efficacy of Alendronate to Treat Osteopenia in Children During Therapy for Acute Lymphoblastic Leukemia: A Retrospective Cohort Study of Sequential Outcomes

BACKGROUND

Low bone mineral density is encountered in children with acute lymphoblastic leukemia (ALL) before, during, and after treatment. Prior experience with alendronate, an oral bisphosphonate, demonstrated high tolerability and evident clinical efficacy. However, concerns have been expressed about the long-term safety and utility of such agents in children.

PROCEDURE

Sixty-nine children with ALL received alendronate for a mean of 87 weeks after dual-energy x-ray absorptiometry. Dual-energy x-ray absorptiometry was repeated following the completion of alendronate, and 5 to 9 years later in a subgroup of 32 children. Lumbar spine areal bone mineral density (LS aBMD) Z scores were obtained.

RESULTS

The mean LS aBMD Z score rose from -1.78 to-0.47 (P <0.0001). There was a modest median loss of LS aBMD subsequently in the 32 subjects on long-term follow-up. Almost 80% (N=172) of the children remain in continuous complete remission at a mean of 14.5 years from diagnosis. Of those who received alendronate, which was almost uniformly well tolerated, 7/69 (10.3%) relapsed compared with 19/89 (21.3%) who did not receive the drug.

DISCUSSION

Alendronate appears to be well tolerated and moderately effective in osteopenic children with ALL. Whether it offers protection against relapse of leukemia needs further study.

Individual Trajectories of Bone Mineral Density Reveal Persistent Bone Loss in Bone Sarcoma Patients: A Retrospective Study

Multiagent chemotherapy offers an undoubted therapeutic benefit to cancer patients, but is also associated with chronic complications in survivors. Osteoporosis affects the quality of life of oncologic patients, especially at the paediatric age. However, very few studies have described the extent of loss of bone mineral density (BMD) in bone sarcoma patients. We analysed a retrospective series of children and adolescents with primary malignant bone tumours (52 osteosarcoma and 31 Ewing sarcoma) and retrieved their BMD at diagnosis and follow-up as Hounsfield units (HU). We studied their individual BMD trajectories before and after chemotherapy up to 5 years, using routine chest CT scan and attenuation thresholds on T12 vertebrae ROI. At one year, bone sarcoma patients showed significant bone loss compared to diagnosis: 17.6% and 17.1% less for OS and EW, respectively. Furthermore, a bone loss of more than 49.2 HU at one-year follow-up was predictive of the persistence of a reduced bone mass over the following 4 years, especially in patients with EW. At 4 years, only 26% and 12.5% of OS and EW, respectively, had recovered or improved their BMD with respect to the onset, suggesting a risk of developing morbidities related to a low BMD in those subjects.

Osteoporosis in Childhood Cancer Survivors: Physiopathology, Prevention, Therapy and Future Perspectives

The improvement of chemotherapy, radiotherapy, and surgical interventions, together with hematopoietic stem cell transplantation, increased childhood cancer survival rate in the last decades, reaching 80% in Europe. Nevertheless, anti-cancer treatments are mainly responsible for the onset of long-term side effects in childhood cancer survivors (CCS), including alterations of the endocrine system function and activity. In particular, the most frequent dysfunction in CCS is a metabolic bone disorder characterized by low bone mineral density (BMD) with increased skeletal fragility. BMD loss is also a consequence of a sedentary lifestyle, malnutrition, and cancer itself could affect BMD, thus inducing osteopenia and osteoporosis. In this paper, we provide an overview of possible causes of bone impairment in CCS in order to propose management strategies for early identification and treatment of skeletal fragility in this population.

It starts from the womb: maximizing bone health

The foundation of bone health is established in utero. Bone accrual starts from the developing fetus and continues throughout childhood and adolescence. This process is crucial to achieve peak bone mass. Understanding factors that influence bone accrual before attainment of peak bone mass is thus critical to improve bone health and prevent osteoporosis, thereby reducing the burden of osteoporotic fractures in older women. In this review, we broadly outline factors influencing peak bone mass from pregnancy to infancy, childhood and adolescence with potential diseases and medications that may affect the optimum trajectory to maximizing bone health. It is estimated that a 10% increase in peak bone mass will delay the onset of osteoporosis by 13 years in a woman.

Prevalence of and factors influencing vitamin D deficiency in paediatric patients diagnosed with cancer at northern latitudes

AIM

To investigate the prevalence of vitamin D deficiency among children with non-haematological malignancies and to explore possible causes of low vitamin D levels among these patients.

METHODS

We performed a cross-sectional study of 458 children diagnosed with solid tumours, brain tumours, non-Hodgkin lymphoma or Hodgkin disease at the University Children's Hospital, Uppsala, Sweden. Serum 25-hydroxyvitamin D and parathyroid hormone levels were measured in samples taken at the time of cancer diagnosis and related to clinical data. Vitamin D deficiency was defined as a 25-hydroxyvitamin D level below 50 nmol/L.

RESULTS

The prevalence rate of vitamin D deficiency among children with non-haematological malignancies was 41%. There was no association between sex or diagnosis and vitamin D status. Vitamin D deficiency was more common among school children than preschool children (51% vs. 24%). Older age, season outside summer, and a more recent calendar year were significant predictors of lower 25-hydroxyvitamin D. There was a significant, albeit weak, negative correlation between 25-hydroxyvitamin D and parathyroid hormone.

CONCLUSION

Vitamin D deficiency is common among children diagnosed with cancer, particularly among school-aged children diagnosed outside summer. The prevalence appears to be increasing, underlining the need for adequate replacement of vitamin D in these patients.

Therapeutic Targeting of the Leukaemia Microenvironment

In recent decades, the conduct of uniform prospective clinical trials has led to improved remission rates and survival for patients with acute myeloid leukaemia and acute lymphoblastic leukaemia. However, high-risk patients continue to have inferior outcomes, where chemoresistance and relapse are common due to the survival mechanisms utilised by leukaemic cells. One such mechanism is through hijacking of the bone marrow microenvironment, where healthy haematopoietic machinery is transformed or remodelled into a hiding ground or "sanctuary" where leukaemic cells can escape chemotherapy-induced cytotoxicity. The bone marrow microenvironment, which consists of endosteal and vascular niches, can support leukaemogenesis through intercellular "crosstalk" with niche cells, including mesenchymal stem cells, endothelial cells, osteoblasts, and osteoclasts. Here, we summarise the regulatory mechanisms associated with leukaemia-bone marrow niche interaction and provide a comprehensive review of the key therapeutics that target CXCL12/CXCR4, Notch, Wnt/b-catenin, and hypoxia-related signalling pathways within the leukaemic niches and agents involved in remodelling of niche bone and vasculature. From a therapeutic perspective, targeting these cellular interactions is an exciting novel strategy for enhancing treatment efficacy, and further clinical application has significant potential to improve the outcome of patients with leukaemia.

Recent perspectives on the association between osteonecrosis and bone mineral density decline in childhood acute lymphoblastic leukemia

The attention to treatment-related toxicity has increased since the survival of children with acute lymphoblastic leukemia (ALL) has improved significantly over the past few decades. Intensive ALL treatment schedules including corticosteroids and asparaginase have been shown to give rise to skeletal abnormalities such as osteonecrosis and low bone mineral density (BMD), which may lead to debilitating sequelae in survivors. Although osteonecrosis and low BMD are different entities with suggested separate pathophysiological mechanisms, recent studies indicate that osteonecrosis is associated with accelerated BMD decline. Common underlying mechanisms for osteonecrosis and BMD decline are considered, such as an enhanced sensitivity to corticosteroids in children who suffer from both osteonecrosis and low BMD. In addition, restriction of weight-bearing activities, which is generally advised in patients with osteonecrosis, could aggravate BMD decline. This induces a clinical dilemma, since bone stimulation is important to maintain BMD but alternative interventions for osteonecrosis are limited. Furthermore, this recent finding of accelerated BMD decline in children with osteonecrosis emphasizes the need to develop effective preventive measures for osteonecrosis, which may include targeting BMD decline.

Genome-wide Association Studies Reveal Novel Locus With Sex-/Therapy-Specific Fracture Risk Effects in Childhood Cancer Survivors

Childhood cancer survivors treated with radiation therapy (RT) and osteotoxic chemotherapies are at increased risk for fractures. However, understanding of how genetic and clinical susceptibility factors jointly contribute to fracture risk among survivors is limited. To address this gap, we conducted genome-wide association studies of fracture risk after cancer diagnosis in 2453 participants of European ancestry from the Childhood Cancer Survivor Study (CCSS) with 930 incident fractures using Cox regression models (ie, time-to-event analysis) and prioritized sex- and treatment-stratified genetic associations. We performed replication analyses in 1417 survivors of European ancestry with 652 incident fractures from the St. Jude Lifetime Cohort Study (SJLIFE). In discovery, we identified a genome-wide significant (p < 5 × 10^-8 ) fracture risk locus, 16p13.3 (HAGHL), among female CCSS survivors (n = 1289) with strong evidence of sex-specific effects (p_{sex-heterogeneity}  < 7 × 10^-6 ). Combining discovery and replication data, rs1406815 showed the strongest association (hazard ratio [HR] = 1.43, p = 8.2 × 10^-9 ; n = 1935 women) at this locus. In treatment-stratified analyses in the discovery cohort, the association between rs1406815 and fracture risk among female survivors with no RT exposures was weak (HR = 1.22, 95% confidence interval [CI] 0.95-1.57, p = 0.11) but increased substantially among those with greater head/neck RT doses (any RT: HR = 1.88, 95% CI 1.54-2.28, p = 2.4 × 10^-10 ; >36 Gray only: HR = 3.79, 95% CI 1.95-7.34, p = 8.2 × 10^-5 ). These head/neck RT-specific HAGHL single-nucleotide polymorphism (SNP) effects were replicated in female SJLIFE survivors. In silico bioinformatics analyses suggest these fracture risk alleles regulate HAGHL gene expression and related bone resorption pathways. Genetic risk profiles integrating this locus may help identify female survivors who would benefit from targeted interventions to reduce fracture risk. © 2020 American Society for Bone and Mineral Research (ASBMR).

Late Effects in Survivors of Neonatal Cancer

The current 5-year survival rate for cancer in infants is greater than 75% in developed countries. However, survivors of neonatal malignancies have an increased risk of late effects from their tumor or its treatment, which may lead to long-term morbidity and/or early mortality. This article reviews surgical approaches and chemotherapeutic agents commonly used in neonatal malignancies and their associated late effects. It also reviews the increased risk for late effects associated with radiation at a young age and hematopoietic stem cell transplantation at a young age.. It highlights the importance of survivor-specific multidisciplinary care in the long-term management of neonatal cancer survivors.

A long-term trajectory of bone mineral density in childhood cancer survivors after discontinuation of treatment: retrospective cohort study

Low bone mineral density (BMD) was diagnosed in 24% of childhood cancer survivors (CCS), whereas very low BMD was relatively uncommon at 8%. We suggest that low BMD in CCS may become alleviated over time. Stem cell transplantation, radiotherapy, and underweight were the strongest independent predictors of decreased BMD.

PURPOSE

Childhood cancer survivors (CCS) are at risk of premature bone loss, although published studies are inconsistent. The objective of this study was to evaluate the prevalence and pattern of low bone mineral density (BMD) in short- and long-term CCS, and to determine clinical factors affecting skeleton after anticancer treatment.

METHODS

This retrospective study was conducted in a cohort of 326 children and young adult CCS (147 females) who completed anticancer treatment. BMD was determined by dual-energy X-ray absorptiometry (DXA). Low BMD was defined as a Z-score ≤ - 1.0, and the very low BMD as a Z-score ≤ - 2.0. Additionally, the changes in BMD over time were studied in 123 CCS who had been re-examined by DXA during follow-up.

RESULTS

Median age at diagnosis was 7.27 years (range, 4.4-10.6); median time between end of treatment and DXA was 6.12 (range, 4.0-22.0). Low BMD was found in 24% of CCS, while very low BMD was relatively uncommon (8%). Based on multivariate analysis, the following were significantly associated with low BMD at the follow-up: hematopoietic stem cell transplantation (OR 3.13, 95% CI 1.02-9.63), head and neck radiotherapy (OR 2.54, 95% CI 1.32-4.90), and body weight below the standard reference (OR 3.57, 95% CI 1.24-10.23). The time-related trajectory showed an improvement (BMD_LS) or stabilization (BMD_TB) in Z-scores values.

CONCLUSION

These data based on serial DXA measurements, encompassing a long-lasting observation period, show that CCS may not be at risk of premature bone loss in young adulthood. However, it is unknown how the scenario for skeletal mass is until the CCS will achieve older or postmenopausal age.

[Endocrine late-effects and bone mineral density after combined treatment of malignant brain tumors in childhood and adolescence]

Обоснование

Обоснование. Внедрение в клиническую практику стандартизированных протоколов комбинированного лечения онкологических заболеваний неизбежно приводит к развитию отдаленных последствий. Поскольку у лиц, излеченных в детском и подростковом возрасте, ожидаемая продолжительность жизни велика, своевременная диагностика и коррекция отдаленных последствий противоопухолевого лечения имеют даже большее значение, чем острые осложнения химиолучевой терапии.

Цель

Цель. Изучить распространенность эндокринных нарушений, оценить распространенность и степень снижения минеральной плотности костной ткани (МПК) у лиц, перенесших комбинированное лечение злокачественных опухолей головного мозга в детском и молодом возрасте.

Материалы и методы

Материалы и методы. Проведено ретроспективное исследование с участием 59 пациентов (31 мужчина; 28 женщин), перенесших в детском и молодом возрасте оперативное лечение злокачественной опухоли головного мозга с последующей лучевой терапией в объеме краниоспинального облучения в сочетании с полихимиотерапией или без нее. I группу составили 37 пациентов, которым комбинированное лечение проводилось в возрасте от 3 до 16 лет. Во II группу были включены 22 пациента, получившие лечение в возрасте от 16 до 38 лет.

Результаты

Результаты. Недостаточность соматотропного гормона по результатам пробы с инсулиновой гипогликемией выявлена у 48 пациентов (81%), вторичная надпочечниковая недостаточность — у 22 (37%). Большая часть обследованных (33 пациента (56%)) не достигли целевого роста. Лечение рекомбинантным гормоном роста (рГР) получили только 5 человек из I группы. Проведенный корреляционный анализ показал, что возраст на момент лечения — основной фактор, влияющий на конечный рост (r=0,619; p<0,001). Выявлена высокая частота развития гипотиреоза (n=39 (66%)), гипогонадизма (19 женщин; 17 мужчин). По результатам DXA снижение МПК ≤-2,0 SD по Z-критерию в поясничном отделе позвоночника выявлено у 35 из 59 обследованных (59%). МПК у пациентов I группы была значимо ниже по сравнению с пациентами, получившими лечение в более старшем возрасте (p<0,001). Обнаружена умеренная корреляция между МПК в поясничном отделе позвоночника на момент обследования и уровнем эстрадиола в крови у женщин (r=0,596; p<0,05) и тестостерона у мужчин (r=0,472; p<0,05). Выявлена прямая зависимость МПК от возраста на момент заболевания (r=0,781; p<0,01).

Заключение

Заключение. Полученные результаты свидетельствуют о необходимости ежегодного и пожизненного наблюдения пациентов после комбинированного лечения злокачественных опухолей головного мозга на предмет выявления отдаленных последствий лечения. Высокая распространенность остеопенических состояний определяет актуальность и необходимость проведения ранней диагностики для предотвращения дальнейшей потери костной массы, снижения прочности кости и риска переломов.

A 3D-Printed Model-Assisted Cervical Spine Instrumentation after Tumor Resection in a 4-Year-Old Child: A Case Report

INTRODUCTION

In the case of tumor resection in the upper cervical spine, a multilevel laminectomy with instrumented fixation is required to prevent kyphotic deformity and myelopathy. Nevertheless, instrumentation of the cervical spine in children under the age of 8 years is challenging due to anatomical considerations and unavailability of specific instrumentation.

CASE PRESENTATION

We present a case of 3D-printed model-assisted cervical spine instrumentation in a 4-year-old child with post-laminectomy kyphotic decompensation of the cervical spine and spinal cord injury 1 year after medulloblastoma metastasis resection in the upper cervical spine. Due to unavailability of specific instrumentation, 3D virtual planning was used to assess and plan posterior cervical fixation. Fixation with 3.5 mm lateral mass and isthmic screws was suggested and the feasibility of fixation was confirmed "in vitro" in a 3D-printed model preoperatively to reduce the possibility of intraoperative implant-spine mismatch. Intraoperative conditions completely resembled the preoperative plan and 3.5 mm polyaxial screws were successfully used as planned. Postoperatively the child made a complete neurological recovery and 2 years after the instrumented fusion is still disease free with no signs of spinal decompensation.

DISCUSSION/CONCLUSION

Our case shows that posterior cervical fixation with the conventional screw-rod technique in a 4-year-old child is feasible, but we suggest that suitability and positioning of the chosen implants are preoperatively assessed in a printed 3D model. In addition, a printed 3D model offers the possibility to better visualize and sense spinal anatomy "in vivo," thereby helping screw placement and reducing the chance for intraoperative complications, especially in the absence of intraoperative spinal navigation.

Relationships of Bone Mineral Density to Whole Body Mass, Fat Mass and Fat-free Mass in Long-term Survivors of Acute Lymphoblastic Leukemia in Childhood

Body size influences bone mineral density (BMD) in health. Relationships of BMD with body mass index, fat mass (FM), fat-free mass, and appendicular lean mass were explored in acute lymphoblastic leukemia (ALL) survivors (n=75; 41 males; 45 standard risk ALL) >10 years from diagnosis. Dual energy radiograph absorptiometry performed body composition analysis. Relationships were assessed by regression analyses and Pearson correlation coefficients (r). Twenty subjects (26.3%) were osteopenic; lumbar spine (LS) BMD Z score <-1.00. Age at diagnosis, sex, ALL risk-category, type of post-induction steroid or cranial radiation did not correlate with LS or whole body (WB) BMD. Body mass index correlated significantly with LS BMD (r=0.333, P=0.004) and WB BMD (r=0.271, P=0.033). FM index (FM/height²) Z score showed no significant correlation with LS or WB BMD. Fat-free mass index Z score correlated strongly with LS BMD (r=0.386, P=0.013) and WB BMD (r=0.605, P<0.001) in males but not in females. The appendicular lean mass index, a surrogate for skeletal muscle mass, correlated significantly with LS BMD (r=0.367, P=0.018) and WB BMD (r=0.604, P<0.001) in males but not in females. Future studies to evaluate interventions to enhance BMD focused on improving body composition particularly skeletal muscle mass are warranted.

The effect of an online exercise programme on bone health in paediatric cancer survivors (iBoneFIT): study protocol of a multi-centre randomized controlled trial

BACKGROUND

New approaches on paediatric cancer treatment aim to maintain long-term health. As a result of radiotherapy, chemotherapy or surgery, paediatric cancer survivors tend to suffer from any chronic health condition. Endocrine dysfunction represents one of the most common issues and affects bone health. Exercise is key for bone mass accrual during growth, specifically plyometric jump training. The iBoneFIT study will investigate the effect of a 9-month online exercise programme on bone health in paediatric cancer survivors. This study will also examine the effect of the intervention on body composition, physical fitness, physical activity, calcium intake, vitamin D, blood samples quality of life and mental health.

METHODS

A minimum of 116 participants aged 6 to 18 years will be randomized into an intervention (n = 58) or control group (n = 58). The intervention group will receive an online exercise programme and diet counselling on calcium and vitamin D. In addition, five behaviour change techniques and a gamification design will be implemented in order to increase the interest of this non-game programme. The control group will only receive diet counselling. Participants will be assessed on 3 occasions: 1) at baseline; 2) after the 9 months of the intervention; 3) 4 months following the intervention. The primary outcome will be determined by dual energy X-ray absorptiometry (DXA) and the hip structural analysis, trabecular bone score and 3D-DXA softwares. Secondary outcomes will include anthropometry, body composition, physical fitness, physical activity, calcium and vitamin D intake, blood samples, quality of life and mental health.

DISCUSSION

Whether a simple, feasible and short in duration exercise programme can improve bone health has not been examined in paediatric cancer survivors. This article describes the design, rationale and methods of a study intended to test the effect of a rigorous online exercise programme on bone health in paediatric cancer survivors. If successful, the iBoneFIT study will contribute to decrease chronic health conditions in this population and will have a positive impact in the society.

TRIAL REGISTRATION

Prospectively registered in isrctn.com: isrctn61195625 . Registered 2 April 2020.

Genome wide association studies for treatment-related adverse effects of pediatric acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common pediatric hematological malignancy; notwithstanding the success of ALL therapy, severe adverse drugs effects represent a serious issue in pediatric oncology, because they could be both an additional life threatening condition for ALL patients per se and a reason to therapy delay or discontinuation with important fallouts on final outcome. Cancer treatment-related toxicities have generated a significant need of finding predictive pharmacogenomic markers for the a priori identification of at risk patients. In the era of precision medicine, high throughput genomic screening such as genome wide association studies (GWAS) might provide useful markers to tailor therapy intensity on patients' genetic profile. Furthermore, these findings could be useful in basic research for better understanding the mechanistic and regulatory pathways of the biological functions associated with ALL treatment toxicities. The purpose of this review is to give an overview of high throughput genomic screening of the last 10 years that had investigated the landscape of ALL treatment-associated toxicities. This article is categorized under: Cancer > Genetics/Genomics/Epigenetics.

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.

Usefulness of X-rays in the Differential Diagnosis of Hypophosphataemic Rickets

Rickets and osteomalacia are two related conditions linked by the lack of mineralization of bone tissue due to a disturbance of calcium and phosphate homeostasis. Some of the most characteristic features of rickets are skeletal deformities, fractures, linear and continuous periosteal reaction, and enlargement of the metaphyseal space in an irregular and frayed form. However, these radiological findings are not exclusive to these diseases, but may also originate in children who were born prematurely or in those who have suffered physical abuse or an accident. Hence, it is important to establish a differential diagnosis. All these observations can be evidenced by radiological images using a simple X-ray. The aim of this article is to show the main radiological findings that can be found in rickets and how to establish a differential diagnosis of X-linked hypophosphataemic (XLH) rickets.

High impact physical activity and bone health of lower extremities in childhood cancer survivors: A cross-sectional study of SURfit

Childhood cancer survivors (CCS) are at risk of reduced bone health and premature osteoporosis. As physical activity with high impact loading (IL-PA) is known to promote bone health, we compared bone densitometry and microstructure between groups of CCS who performed different amounts of physical activities in their daily life. We used baseline data of a single-center PA trial including 161 CCS from the Swiss Childhood Cancer Registry, aged <16 at diagnosis, ≥16 at study and ≥5 years since diagnosis. Lower body bone health was assessed with peripheral quantitative computed tomography (pQCT) and dual-energy X-ray absorptiometry (DXA). Daily IL-PA (duration in activities >2 g acceleration and numbers of vertical impacts/hr >2 g) was captured using hip-worn accelerometers (1-3 weeks). For both IL-PA approaches, we formed low, middle and high activity groups based on tertiles. Bone health of the high and middle active groups was compared to the low active group. 63% of CCS had indication of at least one bone mineral density z-score ≤ -1 measured by pQCT or DXA. The high IL-PA group performing 2.8 min/day or 19.1 impact peaks/hr > 2 g (median) showed about 3-13% better microstructural and densitometric bone health as compared to the low IL-PA group with 0.38 min/day or 0.85 peaks/hr > 2 g. Just a few minutes and repetitions of high IL-PA as easily modifiable lifestyle factor may be sufficient to improve bone health in adult CCS. Future longitudinal research is needed to better understand pattern and dosage of minimal impact loading needed to strengthen bone in growing and adult CCS.

Bone morbidity in pediatric acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL), currently the most common pediatric leukemia, has a high curability rate of up to 90%. Endocrine disorders are highly prevalent in children with ALL, and skeletal morbidity is a major issue induced by multiple factors associated with ALL. Leukemia itself is a predominant risk factor for decreased bone formation, and major bone destruction occurs secondary to chemotherapeutic agents. Glucocorticoids are cornerstone drugs used throughout the course of ALL treatment that exert significant effects on demineralization and osteoclastogenesis. After completion of treatment, ALL survivors are prone to multiple hormone deficiencies that eventually affect bone mineral accrual. Dual-energy X-ray absorptiometry, the most widely used method of measuring bone mineral density, is used to determine the presence of childhood osteoporosis and vertebral fracture. Supplementation with calcium and vitamin D, administration of pyrophosphate analogues, and promotion of mobility and exercise are effective options to prevent further bone resorption and fracture incidence. This review focuses on addressing bone morbidity after pediatric ALL treatment and provides an overview of bone pathology based on skeletal outcomes to increase awareness among pediatric hemato-oncologists and endocrinologists.

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.

Prediction of Low and Very Low Bone Mineral Density Among Adult Survivors of Childhood Cancer

PURPOSE

To develop and validate prediction models for low and very low bone mineral density (BMD) on the basis of clinical and treatment characteristics that identify adult survivors of childhood cancer who require screening by dual-energy x-ray absorptiometry.

PATIENTS AND METHODS

White survivors of childhood cancer (n = 2,032; median attained age, 29.3 years [range, 18.1 to 40.9 years]) enrolled in the St Jude Lifetime Cohort (SJLIFE; development) and survivors treated at the Erasmus Medical Center (validation) in the Netherlands (n = 403; median age, 24.2 years [range, 18.0 to 40.9 years]) were evaluated with dual-energy x-ray absorptiometry to determine lumbar spine BMD and total-body BMD. Low and very low BMD were defined as lumbar spine BMD and/or total-body BMD z scores of -1 or lower or -2 or lower, respectively. Multivariable logistic regression was used to build prediction models; performance was assessed using receiver operating characteristic curves. Diagnostic values were calculated at different probabilities.

RESULTS

Low BMD was present in 51% and 45% of SJLIFE and Dutch participants, respectively, and very low BMD was present in 20% and 10%, respectively. The model for low BMD included male sex (odds ratio [OR], 3.07), height (OR, 0.95), weight (OR, 0.98), attained age (OR, 0.97), current smoking status (OR, 1.48), and cranial irradiation (OR, 2.11). Areas under the curve were 0.72 (95% CI, 0.70 to 0.75) in the SJLIFE cohort and 0.69 (95% CI, 0.64 to 0.75) in the Dutch cohort. The sum of the sensitivity (69.0%) and specificity (64.0%) was maximal at the predicted probability of 50%. The model for very low BMD included male sex (OR, 3.28), height (OR, 0.95), weight (OR, 0.97), attained age (OR, 0.98), cranial irradiation (OR, 2.07), and abdominal irradiation (OR, 1.61), yielding areas under the curve of 0.76 (95% CI, 0.73 to 0.78; SJLIFE cohort) and 0.75 (95% CI, 0.67 to 0.83; Dutch cohort).

CONCLUSION

Validated prediction models for low and very low BMD, using easily measured patient and treatment characteristics, correctly identified BMD status in most white adult survivors through age 40 years.

Long-Term Endocrine and Metabolic Consequences of Cancer Treatment: A Systematic Review

The number of patients surviving ≥5 years after initial cancer diagnosis has significantly increased during the last decades due to considerable improvements in the treatment of many cancer entities. A negative consequence of this is that the emergence of long-term sequelae and endocrine disorders account for a high proportion of these. These late effects can occur decades after cancer treatment and affect up to 50% of childhood cancer survivors. Multiple predisposing factors for endocrine late effects have been identified, including radiation, sex, and age at the time of diagnosis. A systematic literature search has been conducted using the PubMed database to offer a detailed overview of the spectrum of late endocrine disorders following oncological treatment. Most data are based on late effects of treatment in former childhood cancer patients for whom specific guidelines and recommendations already exist, whereas current knowledge concerning late effects in adult-onset cancer survivors is much less clear. Endocrine sequelae of cancer therapy include functional alterations in hypothalamic-pituitary, thyroid, parathyroid, adrenal, and gonadal regulation as well as bone and metabolic complications. Surgery, radiotherapy, chemotherapy, and immunotherapy all contribute to these sequelae. Following irradiation, endocrine organs such as the thyroid are also at risk for subsequent malignancies. Although diagnosis and management of functional and neoplastic long-term consequences of cancer therapy are comparable to other causes of endocrine disorders, cancer survivors need individually structured follow-up care in specialized surveillance centers to improve care for this rapidly growing group of patients.

The Impact of Physical Activity on the Health of Young Adult Survivors of Childhood Cancer: An Exploratory Analysis

Purpose: Physical activity (PA) habits of young adult survivors of childhood cancer (SCC) have not been well-characterized, and it is unclear whether PA has a relationship with the health status of young adult SCC. The objective of this study was to determine PA participation of young adult SCC and examine associations between PA participation and late adverse effects of treatment. Methods: A retrospective chart review, including SCC enrolled in the McMaster AfterCare program, was performed. Patient characteristics, health outcomes, and PA information were abstracted. Multivariable logistic regression models were used to examine associations in this exploratory analysis. Results: We identified 253 young adult SCC, 240 of whom had sufficient information on PA participation to determine a Leisure Score Index (LSI). Of these, 45% reported adequate PA (LSI ≥24) and 26% reported no PA (LSI = 0). Significant associations between PA and bone mineral density (p = 0.03), blood pressure (p = 0.04), triglycerides (p = 0.05), and high-density lipoprotein cholesterol (p < 0.01) were demonstrated. Conclusions: The majority of young adult SCC in this cohort reported inadequate PA, despite ongoing healthy active living counseling. We identified associations between PA and bone mineral density as well as lipid profile in this group, which suggest that PA may mitigate risk of sequelae of cancer treatment. Strategies to improve young adult SCC engagement in PA are required.

Mandibular radiomorphometric assessment of bone mineral density in survivors of pediatric hematopoietic stem-cell transplantation

OBJECTIVE

Hematopoietic stem-cell transplantation (HSCT) childhood survivors of hematologic malignancies are prone to develop late osteopenia and osteoporosis. The purpose of this retrospective study was to quantitatively and qualitatively assess bone mineral density (BMD) in HSCT childhood survivors and to compare the effectiveness of both qualitative and quantitative assessment methods.

METHODS

DESIGN BMD assessment using panoramic radiographs of childhood HSCT survivors aged 3.69-18.88 years using two radiomorphometric indexes. Case-control double-blinded comparison of panoramic radiographic images from childhood HSCT survivors and age- and sex-matched healthy controls. Quantitative assessment was performed by measuring the cortical bone width bilaterally at the mental foramen level. Qualitative assessment was performed using the mandibular cortical index bilaterally on all panoramic images.

RESULTS

Radiographs were taken 6.59-83.95 months after bone marrow transplantation [median±SD=25.92±24.9 months]. Fifty-two panoramic radiographic images were analyzed: 21 from HSCT survivors and 31 from healthy controls aged 3.69-25.1 years [mean±SD=11.89±5.28 years]. The mandibular cortical bone width was 17% smaller in childhood HSCT survivors than in healthy controls (case group: 2.420, control group: 3.307; p=0.00617). Qualitative analysis revealed an increased frequency of severe mandibular cortical erosion in childhood HSCT survivors, although no significant difference was observed (case group: 1.540, control group: 1.490; p=0.32). The interobserver agreement was 85% (Kappa index).

CONCLUSIONS

HSCT childhood survivors exhibit quantitative and qualitative mandibular bone impairments. Further studies are needed to establish an association between mandibular cortical bone impairment and osteoporosis.

Late Effects and Survivorship Issues in Patients with Neuroblastoma

Over the past two decades, marked progress has been made in understanding the biology of neuroblastoma; this has led to refined risk stratification and treatment modifications with resultant increasing 5-year survival rates for children with neuroblastoma. Survivors, however, remain at risk for a wide variety of potential treatment-related complications, or "late effects", which may lead to excess morbidity and premature mortality in this cohort. This review summarizes the existing survivorship literature on long-term health outcomes for survivors of neuroblastoma, focusing specifically on potential injury to the endocrine, sensory, cardiovascular, pulmonary, and renal systems, as well as survivors' treatment-related risk for subsequent neoplasms and impaired quality of life. Additional work is needed to assess the potential late effects of newer multimodality therapies with the aim of optimizing long-term medical and psychosocial outcomes for all survivors of neuroblastoma.

Investigating the bone mineral density in children with solid tumors in southern Iran: a case-control study

Along with increasing childhood cancer survival, there is increasing concern about its chronic complications. We showed that 20.5 and 45.9% of children with solid tumors in southern Iran had low bone mass for chronological age in lumbar and femoral area, which was associated with serum ferritin and hemoglobin. 52.4% of these children had vitamin D deficiency, as well.

PURPOSE/INTRODUCTION

Along with increasing the childhood cancer survival, there is increasing concern about the chronic complications of the disease and the related therapies. This study aims to compare the vitamin D status and bone mineral apparent density (BMAD) of these children with healthy ones and assess some possible associated factors.

METHOD

This case-control study enrolled 50 children with solid tumors and their age- and sex-matched controls. Dual-energy X-ray absorptiometry was used to assess bone mineral density. Body mass index, puberty, physical activity, sun exposure, and biochemical data were assessed.

RESULTS

52.4% of children with solid tumors had vitamin D deficiency, and there was no significant difference between the prevalence of vitamin D deficiency in patients and controls (P = 0.285). The prevalence of low bone mass for chronological age in lumbar area was 20.5 and 12.5% in patients and controls, respectively (P = 0.399). Lumbar spine BMD was associated with hemoglobin level (r = 0.468, P = 0.049), while low bone mass in femoral neck was associated with serum ferritin (859 ± 1037 in low bone mass vs. 178 ± 264 in without low bone mass, P = 0.039).

CONCLUSION

Vitamin D deficiency and low bone mass are prevalent among Iranian children with solid tumors. Future studies are warranted to investigate the best strategies to prevent and treat vitamin D deficiency and low bone mass in children surviving cancer.

Risk factors and surveillance for reduced bone mineral density in pediatric cancer survivors

BACKGROUND

Pediatric cancer survivors are at increased risk of developing low bone mineral density (BMD) due to cancer treatment. This study assessed the yield of screening for low BMD in pediatric-aged cancer survivors as per the Children's Oncology Group Long-Term Follow-Up (COG-LTFU) Guidelines, which recommend screening survivors who received steroids, methotrexate, or hematopoietic cell transplant (HCT).

METHODS

This is a retrospective cohort study of 475 pediatric blood cancer and noncentral nervous system solid tumor survivors screened for low BMD with dual-energy X-ray absorptiometry (DXA) as per the COG-LTFU Guidelines from 2003 to 2010. Risk factors for low BMD (DXA Z-score ≤-2) were evaluated by univariate and multivariate analysis.

RESULTS

The mean DXA Z-score was -0.1 for both whole body and lumbar spine measurements. Among at-risk survivors, 8.2% (39/475) had low BMD. Multivariate analysis of survivors with low BMD showed significant association with male gender (odds ratio [OR] 3.4, 95% confidence interval [CI], 1.3-9.0), exposure to total body irradiation (TBI), cranial, or craniospinal radiation (OR 5.2, 95% CI, 1.8-14.9), and gonadal dysfunction (OR 4.3, 95% CI, 1.4-13.0). Methotrexate exposure was not significantly associated with low BMD. Survivors receiving HCT had a reduced risk of low BMD (OR 0.2, 95% CI, 0.1-0.9).

CONCLUSION

The highest risk factors for low BMD were male gender, exposure to TBI, cranial, or craniospinal radiation, and gonadal dysfunction. Survivors receiving methotrexate or HCT therapy have the lowest risk for low BMD among those screened. Future studies should investigate risk of low BMD for survivors receiving HCT without radiation exposure.

The skeletal impact of the chemotherapeutic agent etoposide

Effects of the chemotherapeutic agent etoposide on the skeleton were determined in mice. Numbers of bone marrow cells were reduced and myeloid cells were increased. Bone volume was significantly decreased with signs of inhibition of bone formation. Etoposide after pre-treatment with zoledronic acid still reduced bone but overall bone volume was higher than with etoposide alone.

INTRODUCTION

Chemotherapeutics target rapidly dividing tumor cells yet also impact hematopoietic and immune cells in an off target manner. A wide array of therapies have negative side effects on the skeleton rendering patients osteopenic and prone to fracture. This study focused on the pro-apoptotic chemotherapeutic agent etoposide and its short- and long-term treatment effects in the bone marrow and skeleton.

METHODS

Six- to 16-week-old mice were treated with etoposide (20-25 mg/kg) or vehicle control in short-term (daily for 5-9 days) or long-term (3×/week for 17 days or 6 weeks) regimens. Bone marrow cell populations and their phagocytic/efferocytic functions were analyzed by flow cytometry. Blood cell populations were assessed by CBC analysis. Bone volume and area compartments and osteoclast numbers were measured by microCT, histomorphometry, and TRAP staining. Biomarkers of bone formation (P1NP) and resorption (TRAcP5b) were assayed from serum. Gene expression in bone marrow was assessed using qPCR.

RESULTS

Flow cytometric analysis of the bone marrow revealed short-term etoposide reduced overall cell numbers and B220+ cells, with increased marrow apoptotic (AnnexinV+PI-) cells, mesenchymal stem-like cells, and CD68+, CD45+, and CD11b+ monocyte/myeloid cells (as a percent of the total marrow). After 6 weeks, the CD68+, Gr1+, CD11b+, and CD45+ cell populations were still relatively increased in etoposide-treated bone marrow. Skeletal phenotyping revealed etoposide decreased bone volume, trabecular thickness, and cortical bone volume. Gene expression in the marrow for the leptin receptor and CXCL12 were reduced with short-term etoposide, and an increased ratio of RANKL/OPG mRNA was observed. In whole bone, Runx2 and osteocalcin gene expressions were reduced, and in serum, P1NP was significantly reduced with etoposide. Treatment with the antiresorptive agent zoledronic acid prior to etoposide increased bone volume and improved the etoposide-induced decrease in skeletal parameters.

CONCLUSIONS

These data suggest that etoposide induces apoptosis in the bone marrow and significantly reduces parameters of bone formation with rapid reduction in bone volume. Pre-treatment with an antiresorptive agent results in a preservation of bone mass. Preventive approaches to preserving the skeleton should be considered in human clinical studies.

Oral Treatment with the Ghrelin Receptor Agonist HM01 Attenuates Cachexia in Mice Bearing Colon-26 (C26) Tumors

The gastrointestinal hormone ghrelin reduces energy expenditure and stimulates food intake. Ghrelin analogs are a possible treatment against cancer anorexia-cachexia syndrome (CACS). This study aimed to investigate whether oral treatment with the non-peptidergic ghrelin receptor agonist HM01 counteracts CACS in colon-26 (C26) tumor-bearing mice. The C26 tumor model is characterized by pronounced body weight (BW) loss and muscle wasting in the absence of severe anorexia. We analyzed the time course of BW loss, body composition, muscle mass, bone mineral density, and the cytokines interleukin-6 (IL-6) and macrophage-inhibitory cytokine-1 (MIC-1). Moreover, we measured the expression of the muscle degradation markers muscle RING-finger-protein-1 (MuRF-1) and muscle atrophy F-box (MAFbx). After tumor inoculation, MIC-1 levels increased earlier than IL-6 and both cytokines were elevated before MuRF-1/MAFbx expression increased. Oral HM01 treatment increased BW, fat mass, and neuronal hypothalamic activity in healthy mice. In tumor-bearing mice, HM01 increased food intake, BW, fat mass, muscle mass, and bone mineral density while it decreased energy expenditure. These effects appeared to be independent of IL-6, MIC-1, MuRF-1 or MAFbx, which were not affected by HM01. Therefore, HM01 counteracts cachectic body weight loss under inflammatory conditions and is a promising compound for the treatment of cancer cachexia in the absence of severe anorexia.

Non-infectious chemotherapy-associated acute toxicities during childhood acute lymphoblastic leukemia therapy

During chemotherapy for childhood acute lymphoblastic leukemia, all organs can be affected by severe acute side effects, the most common being opportunistic infections, mucositis, central or peripheral neuropathy (or both), bone toxicities (including osteonecrosis), thromboembolism, sinusoidal obstruction syndrome, endocrinopathies (especially steroid-induced adrenal insufficiency and hyperglycemia), high-dose methotrexate-induced nephrotoxicity, asparaginase-associated hypersensitivity, pancreatitis, and hyperlipidemia. Few of the non-infectious acute toxicities are associated with clinically useful risk factors, and across study groups there has been wide diversity in toxicity definitions, capture strategies, and reporting, thus hampering meaningful comparisons of toxicity incidences for different leukemia protocols. Since treatment of acute lymphoblastic leukemia now yields 5-year overall survival rates above 90%, there is a need for strategies for assessing the burden of toxicities in the overall evaluation of anti-leukemic therapy programs.

Skeletal outcome in long-term survivors of childhood high-risk neuroblastoma treated with high-dose therapy and autologous stem cell rescue

High-dose therapy and hematopoietic stem cell transplantation (HSCT) have been shown to improve survival rates in high-risk neuroblastoma (HR-NBL), but may cause adverse effects on the growing skeleton. We studied skeletal health in a national cohort of long-term survivors of HR-NBL (n=21; age 16-30 years, median 22 years) and in 20 healthy age- and sex-matched controls. In addition to clinical evaluation and measurement of bone mineral density (BMD) by dual-energy X-ray absorptiometry, we performed spinal magnetic resonance imaging. Skeletal complications were categorized according to Common Terminology Criteria for Adverse Events (CTCAE). Altogether, 18/21 survivors presented with at least one skeletal adverse event according to CTCAE, the most common skeletal complications being short stature (n=14) and osteopenia (n=13). Altogether, 38% of the subjects had a severe complication (CTCAE score ⩾3) including bilateral slipped capital femoral epiphyseolysis in 3/21. Fracture rate was not increased. In spinal MRI, no vertebral fractures were found and degenerative intervertebral disc changes were equally prevalent in survivors and controls. BMD was lower in survivors than controls, but differences became non-significant when adjusted for bone size. In conclusion, skeletal late complications are common and can significantly impair the quality of life in young adult survivors of HR-NBL treated with high-dose protocols and HSCT.

Changes in Bone Health During the First Year of Cancer Treatment in Children

This study aimed to evaluate longitudinal changes in bone mineral density (BMD) and bone mineral content (BMC) in children with cancer during the first year of treatment. Thirty pediatric cancer patients (median age 11.2 [range 3.8-17.4] yr; 21 boys, 9 girls; 19 hematologic malignancies, 11 solid tumors) and 30 healthy controls were enrolled. Dual energy X-ray absorptiometry was performed at baseline and at 1, 6, and 12 mo for each pediatric cancer patient. There were no significant differences in age, sex, body weight, height, body mass index, serum vitamin D levels, BMD, and BMC among children with hematologic malignancies, those with solid tumors, and the controls at baseline. When the medians of BMD Z-scores were compared between different time intervals, whole-body BMD Z-score significantly decreased during the first year of cancer treatment (p = 0.001) in children with hematologic malignancies, especially during the first month (p = 0.002), and between 1 and 6 mo (p = 0.006). In children with solid tumors, whole-body BMD Z-score changed significantly only between 6 and 12 mo after treatment (p = 0.043). Generalized estimation equations for the analysis of trends in the whole-body BMD Z-scores revealed that there were significant downward trends between BMD Z-scores at baseline and those at 12 mo in children with hematologic malignancies and those with solid tumors. Cancer treatment significantly affects the bone health status at least during the first year, causing a significant decrease in BMD, especially during the first 6 mo for patients with hematologic malignancies and during the last 6 mo for those with solid tumors. Better strategies for treating changes in BMD based on the underlying cancer are necessary during cancer treatment in children.

Genetic variation and bone mineral density in long-term adult survivors of childhood cancer

PURPOSE

Despite similarities in upfront treatment of childhood cancer, not every adult survivor of childhood cancer (CCS) has an impaired bone mineral density (BMD). No data are available on the role of genetic variation on impairment of BMD in CCS.

METHODS

This cross-sectional single-center cohort study included 334 adult CCSs (median follow-up time after cessation of treatment: 15 years; median age at follow-up: 26 years). Total body BMD (BMD_TB ) and lumbar spine BMD (BMD_LS ) were measured by dual x-ray absorptiometry. We selected 12 candidate single-nucleotide polymorphisms (SNPs) in 11 genes (COL1A1, TNFSF11, TNFRSF11, TNRFSA11B, VDR, ESR1, WLS, LRP5, MTHFR, MTRR, IL-6).

RESULTS

Multivariate analyses revealed that lower BMD was associated with lower weight and height at follow-up, male sex, and previously administered radiotherapy. Survivors with the homozygous minor allele (GG) genotype of rs2504063 (ESR1: estrogen receptor type 1) had a lower BMD_TB values (-1.16 vs. -0.82; P = 0.01) than those with the AG/AA genotype; however, BMD_LS was not different. Carriers of two minor alleles (GG) of rs599083 (LRP5: low-density lipoprotein receptor) revealed lower BMD_TB (-1.20 vs. -0.78; P = 0.02) and lower BMD_LS (-0.95 vs. -0.46; P = 0.01) values than those with the TT/TG genotype.

CONCLUSION

CCSs who are carriers of candidate SNPs in the ESR1 or LRP5 genes seem to have an impaired bone mass at an early adult age. Information on genetic variation, in addition to patient- and treatment-related factors, may be helpful in identifying survivors who are at risk for low bone density after childhood cancer treatment.

Bone mineral density in children with acute leukemia and its associated factors in Iran: a case-control study

Acute leukemia is the most common malignancy in children. We showed that low bone mass is prevalent among children with leukemia, especially in femur. Serum calcium, exercise, chemotherapy protocol, and radiotherapy are the main contributing factors. We suggest that early diagnosis and treatment of this problem could improve bone health in them.

INTRODUCTION

Acute leukemia is the most common malignancy in children and has been reported to be associated with low bone mass. Due to lack of sufficient data about the bone mineral density of children with leukemia in the Middle East, and inconsistencies between possible associated factors contributing to decreasing bone density in these children, we aimed to conduct a case-control study in Iran.

MATERIALS AND METHODS

This case-control study was conducted on 60 children with acute leukemia and 60 age- and sex-matched healthy controls. Anthropometric data, sun exposure, puberty, physical activity, and mineral biochemical parameters were assessed. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DEXA). Data analysis was done by SPSS software v. 21.

RESULTS

Serum calcium was higher in the control group (P = 0.012) while serum phosphorous, alkaline phosphatase, and serum 25(OH)D₃ were higher in children with leukemia with P values of 0.04, 0.002, and 0.036, respectively. Sun exposure and physical activity were more in healthy controls (P values <0.001 and 0.003, respectively). Prevalence of vitamin D deficiency in case and control groups was 57.8 and 79.4 %, respectively. This prevalence was higher in healthy controls (P value = 0.007). Both lumbar and femoral neck bone mineral apparent density (BMAD) were higher in the control group (P value <0.001). Serum calcium, physical activity, and radiotherapy were the most relevant factors associated with lumbar BMAD. Femoral neck BMAD was associated with chemotherapy protocol.

CONCLUSION

Low bone mass for chronological age is prevalent among children with leukemia, especially in the femoral neck. Serum calcium, physical activity, chemotherapy protocol, and radiotherapy are the main contributing factors.