Longitudinal evaluation of bone mineral density in children receiving chemotherapy

A Validated Risk Prediction Model for Bone Fragility in Children With Acute Lymphoblastic Leukemia

Although bone fragility may already be present at diagnosis of pediatric acute lymphoblastic leukemia (ALL), routine performance of dual-energy X-ray absorptiometry (DXA) in every child is not universally feasible. The aim of this study was to develop and validate a risk prediction model for low lumbar spine bone mineral density (LS BMD Z-score ≤ -2.0) at diagnosis, as an important indicator for fracture risk and further treatment-related BMD aggravation. Children with ALL (4-18 years), treated according to the Dutch Childhood Oncology Group protocol (DCOG-ALL9; model development; n = 249) and children from the Canadian Steroid-Associated Osteoporosis in the Pediatric Population cohort (STOPP; validation; n = 99) were included in this study. Multivariable logistic regression analyses were used to develop the prediction model and to confirm the association of low LS BMD at diagnosis with symptomatic fractures during and shortly after cessation of ALL treatment. The area under the receiver operating characteristic curve (AUC) was used to assess model performance. The prediction model for low LS BMD at diagnosis using weight (β = -0.70) and age (β = -0.10) at diagnosis revealed an AUC of 0.71 (95% CI, 0.63-0.78) in DCOG-ALL9 and 0.74 (95% CI, 0.63-0.84) in STOPP, and resulted in correct identification of 71% of the patients with low LS BMD. We confirmed that low LS BMD at diagnosis is associated with LS BMD at treatment cessation (OR 5.9; 95% CI, 3.2-10.9) and with symptomatic fractures (OR 1.7; 95% CI, 1.3-2.4) that occurred between diagnosis and 12 months following treatment cessation. In meta-analysis, LS BMD at diagnosis (OR 1.6; 95% CI, 1.1-2.4) and the 6-month cumulative glucocorticoid dose (OR 1.9; 95% CI, 1.1-3.2) were associated with fractures that occurred in the first year of treatment. In summary, a prediction model for identifying pediatric ALL patients with low LS BMD at diagnosis, as an important indicator for bone fragility, was successfully developed and validated. This can facilitate identification of future bone fragility in individual pediatric ALL patients. © 2021 American Society for Bone and Mineral Research (ASBMR).

B cell acute lymphoblastic leukemia cells mediate RANK-RANKL-dependent bone destruction

Although most children survive B cell acute lymphoblastic leukemia (B-ALL), they frequently experience long-term, treatment-related health problems, including osteopenia and osteonecrosis. Because some children present with fractures at ALL diagnosis, we considered the possibility that leukemic B cells contribute directly to bone pathology. To identify potential mechanisms of B-ALL-driven bone destruction, we examined the p53 ^-/-; Rag2 ^-/-; Prkdc^scid/scid triple mutant (TM) mice and p53 ^-/-; Prkdc^scid/scid double mutant (DM) mouse models of spontaneous B-ALL. In contrast to DM animals, leukemic TM mice displayed brittle bones, and the TM leukemic cells overexpressed Rankl, encoding receptor activator of nuclear factor κB ligand. RANKL is a key regulator of osteoclast differentiation and bone loss. Transfer of TM leukemic cells into immunodeficient recipient mice caused trabecular bone loss. To determine whether human B-ALL can exert similar effects, we evaluated primary human B-ALL blasts isolated at diagnosis for RANKL expression and their impact on bone pathology after their transplantation into NOD.Prkdc^scid/scidIl2rg^tm1Wjl /SzJ (NSG) recipient mice. Primary B-ALL cells conferred bone destruction evident in increased multinucleated osteoclasts, trabecular bone loss, destruction of the metaphyseal growth plate, and reduction in adipocyte mass in these patient-derived xenografts (PDXs). Treating PDX mice with the RANKL antagonist recombinant osteoprotegerin-Fc (rOPG-Fc) protected the bone from B-ALL-induced destruction even under conditions of heavy tumor burden. Our data demonstrate a critical role of the RANK-RANKL axis in causing B-ALL-mediated bone pathology and provide preclinical support for RANKL-targeted therapy trials to reduce acute and long-term bone destruction in these patients.

Vitamin D supplementation for children with cancer: A systematic review and consensus recommendations

Background

Prevalent vitamin D deficiency (VDD) and low bone mineral density (BMD) have led to vitamin D supplementation for children with cancer, regardless vitamin D status. However, it remains unsettled whether this enhances bone strength. We sought to address this issue by carrying out a systematic review of the literature.

Methods

We conducted a literature search using PubMed, Embase, and Cochrane databases. Studies including children up to 5 years after cancer therapy were assessed for the association between 25‐hydroxyvitamin D (25OHD) levels and BMD Z‐scores or fractures, and the effect of vitamin D supplementation on BMD or fractures. Evidence quality was assessed using the GRADE methodology.

Results

Nineteen studies (16 observational and 3 interventional, mainly involving children with hematologic malignancies) were included. One study which analyzed 25OHD as a threshold variable (≤10 ng/ml) found a significant association between 25OHD levels and BMD Z‐scores, while 25OHD as a continuous variable was not significantly associated with BMD Z‐scores in 14 observational studies. We found neither a significant association between lower 25OHD levels and fractures (2 studies), nor between vitamin D (and calcium) supplementation and BMD or fracture frequency (3 studies) (very low quality evidence).

Conclusion

There is a lack of evidence for an effect of vitamin D (and calcium) supplementation on BMD or fractures in children with cancer. Further research is needed; until then, we recommend dietary vitamin D/calcium intake in keeping with standard national guidelines, and periodic 25OHD monitoring to detect levels <20 ng/ml. Vitamin D/calcium supplementation is recommended in children with low levels, to maintain levels ≥20 ng/ml year‐long.

Spinal changes after craniospinal irradiation in pediatric patients

BACKGROUND

To evaluate long-term degenerative changes in bone and soft tissue after craniospinal irradiation (CSI).

PROCEDURE

An analysis was performed for 892 vertebral bodies in 220 pediatric patients treated with CSI. To analyze vertebral growth, vertebral body height was calculated. Signal changes for vertebral bodies on MRI, scoliosis and kyphosis, degenerative changes of vertebral bones and discs, and wedging or vertebral height loss were analyzed on images, and factors that influenced these changes were investigated.

RESULTS

Vertebral growth was significantly correlated with radiation dose and growth hormone (GH) deficiency. Growth rate was significantly worse at a dose >39 Gy. Fatty marrow change was found in 83% of patients, 31% had disc degenerative changes, 13% had degenerative changes of spinal bones, 17% had wedging or spinal height loss, and 27% had scoliosis.

CONCLUSIONS

Vertebral bone growth was significantly reduced when high doses were administered, and adequate GH replacement was important for bone growth. Even with symmetrical irradiation, the risk of scoliosis is high after CSI. There was also frequent progression of spinal demineralization and degenerative changes after CSI. Therefore, careful attention should be paid to spinal symptoms as pediatric patients grow into adulthood.

Bone Mineral Density in Survivors of Childhood Acute Lymphoblastic Leukemia

Background:

The objective of this study was to evaluate bone mineral density (BMD) after completion of treatment for childhood acute lymphoblastic leukemia (ALL).

Methods:

In this cross-sectional study, 103 survivors of ALL aged 13.5 ± 0.45 who completed their treatment at least one year earlier were enrolled. Among these, 49.5% and 51.5% received chemotherapy alone and chemotherapy plus cranial radiotherapy, respectively. Bone mineral content, BMD, and bone mineral apparent density in the lumbar spine (LS), femoral neck (FN) and forearm were assessed using dual-energy X-ray absorptiometry (DEXA). BMD Z-scores were classified according to International Society for Clinical Densitometry (ISCD) criteria.

Results:

The mean BMD Z-scores ± SD forLS, FN and forearm were -1.60 ± 0.12, -1.21 ± 0.9 and -2.43 ± 0.14 respectively with significant differences (P<0.001). Considering the lowest BMD Z-score in LS and FN areas (at any site) and according to the ISCD classification, 62.1%, 33% and 4.9% of the patients had normal BMD, low BMD and osteoporosis, respectively. Also, 8.7% of patients had developed fractures after completion of the treatment period, 4.9% having BMD Z-Scores <-2 SD at any site. A direct relationship was apparent between BMD Z-scores at LS and FN at any sites and risk of fracture (P<0.001).

Conclusions:

ALL patients are at risk for low BMD and fracture. Therefore, applying DEXA scanning is recommended after completion of therapy for prevention of BMD reduction and osteoporosis.

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.

The Incidence of and Factors Associated with Vitamin D Deficiency in Newly Diagnosed Children with Cancer

This retrospective chart review study aimed to assess vitamin D status and identify risk factors associated with vitamin D deficiency and bone parameters in children with cancer at admission. The data of 86 (50 males and 36 females) patients between April 2013 and June 2015 were analyzed. Calcium, phosphorus, alkaline phosphatase (ALP), 25(OH)D, age, gender, diagnostic category, body mass index, duration of complaints, and season of blood sampling were recorded. Median age was 7.17 years (range 0.31-17.40) in 29 hematological malignancy and 57 solid tumor patients. According to cut-off level of 20 ng/ml, 63% of children with cancer had vitamin D deficiency at diagnosis with a median 25(OH)D of 16.75 ng/ml. The mean vitamin D value of children >10 years was significantly low in comparison to that observed in younger children [11.83, 95% confidence interval (CI) = = 8.85-14.81 ng/ml vs. 19.81, 95% CI = = 17.02-22.60 ng/ml]. Vitamin D measurement between November and May was a risk factor for vitamin D deficiency (P < 0.05). The frequency of hypocalcemia and hypophosphatemia was not different between two groups of vitamin D. Further longitudinal studies are needed to investigate whether monitoring vitamin D status and supplementation in children with cancer might prevent future complications related to vitamin D deficiency.

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.

Bone health in children and adolescents with steroid-sensitive nephrotic syndrome assessed by DXA and QUS

BACKGROUND

The management of steroid-sensitive nephrotic syndrome (SSNS) requires treatment with high-dose glucocorticoids (GCs), but GC usage causes the most frequent form of drug-induced osteoporosis. The aim of our study was to evaluate the impact of GCs on bone mineralization in patients with SSNS using two diagnostic tools, dual-energy X-ray densitometry (DXA) and quantitative ultrasound (QUS), and to compare the diagnostic efficacy of these two imaging tools.

METHODS

A total of 30 children with SSNS (age 5.20 ± 2.20 years) were evaluated at the start (T0) and after 1 (T1), 2.44 ± 0.75 (T2, 18 patients) and 5.96 ± 2.33 years (T4, 12 patients) of GC treatment. Patients who stopped at T2 were also evaluated at the 1-year timepoint after ceasing GC treatment (T3).

RESULTS

Of the patients assessed at T2, 11 had bone mineralization at the lower limit of normal versus those at T0 and T1, with bone mineralization rescue at the 1-year timepoint after GC discontinuation. At T4, 6/12 patients had densitometric parameters at the lower limit of normal values, and 3/12 patients showed reduced bone mineralization. The parameters derived from measurements of DXA and QUS were significantly related to each timepoint.

CONCLUSIONS

Patients with SSNS receiving GC therapy undergo bone status alteration related to the dosage and duration of the therapy. In terms of diagnostic efficacy, DXA and QUS were comparable, indicating that QUS is a reliable tool to evaluate bone health in children with SSNS.

Bone morbidity in childhood leukemia: epidemiology, mechanisms, diagnosis, and treatment

Skeletal abnormalities are commonly seen in children and adolescents with leukemia. The spectrum ranges from mild pain to debilitating osteonecrosis (ON) and fractures. In this review, we summarize the skeletal manifestations, provide an update on therapeutic strategies for prevention and treatment, and discuss the most recent advances in musculoskeletal research. Early recognition of skeletal abnormalities and strategies to optimize bone health are essential to prevent long-term skeletal sequelae and diminished quality of life observed in children and adolescents with leukemia.

Bone mineral density among long-term survivors of childhood acute lymphoblastic leukemia: results from the St. Jude Lifetime Cohort Study

BACKGROUND

The prevalence of low bone mineral density (BMD) in adult survivors of childhood acute lymphoblastic leukemia (ALL), and the degree of recovery or decline, are not well elucidated.

PROCEDURE

Study subjects (age ≥ 18 years and ≥10 years post-diagnosis) participated in an institutional follow-up protocol and risk-based clinical evaluation based on Children's Oncology Group guidelines. Trabecular volumetric BMD was ascertained using quantitative computed tomography, reported as age- and sex-specific Z-scores.

RESULTS

At median age 31 years, 5.7% of 845 subjects had a BMD Z-score of ≤-2 and 23.8% had a Z-score of -1 to -2. Cranial radiation dose of ≥24 Gy, but not cumulative methotrexate or prednisone equivalence doses, was associated with a twofold elevated risk of a BMD Z-score of ≤-1. The cranial radiation effect was stronger in females than in males. In a subset of 400 subjects, 67% of those who previously had a BMD Z-score of ≤-2 improved by one or more categories a median of 8.5 years later.

CONCLUSIONS

Very low BMD was relatively uncommon in this sample of adult survivors of childhood ALL, and BMD Z-scores tended to improve from adolescence to young adulthood. High-dose cranial or craniospinal radiation exposure was the primary predictor of suboptimal BMD in our study. Given that cranial radiation treatment for childhood ALL is used far more sparingly now than in earlier treatment eras, concerns about persistently low BMD among most current childhood ALL patients may be unwarranted.

Bone mineral deficits in recipients of hematopoietic cell transplantation: the impact of young age at transplant

Low bone mineral density (BMD) has been reported in recipients of pediatric hematopoietic cell transplantation (HCT), but it is unclear whether age at HCT plays a role. The objective of this cross-sectional study was to determine if patients treated with HCT before age 10 years have long-term BMD deficits compared to patients transplanted at an older age and to sibling controls. The study included 151 HCT recipients (87 males), age at study 24.7±8.6 years treated with HCT for hematologic malignancies at age 10.9±6.4 years, and 92 healthy sibling controls (49 males), age at study 22.3±8.0 years. Dual-energy x-ray absorptiometry was performed to measure BMD Z-scores for total body (TBMD), lumbar spine (LBMD), and femoral neck (FNBMD, for subjects ≥20 years at study visit). Patients <10 years at HCT had significantly lower TBMD and FNBMD Z-scores (by 0.5 and 0.8 SD, respectively) compared to controls (P=0.003 and P=0.0001, respectively) and patients >18 years at HCT (P=0.04 and P=0.004, respectively) at an average of 14 years after HCT. In conclusion, this study identified young age at transplant as an important risk factor for bone deficits in young adulthood, suggesting that efforts to reduce bone loss should focus on this patient population.

Fractures among long-term survivors of childhood cancer: a report from the Childhood Cancer Survivor Study

BACKGROUND

Although reductions in bone mineral density are well documented among children during treatment for cancer and among childhood cancer survivors, little is known about the long-term risk of fracture. The objective of this study was to ascertain the prevalence of and risk factors for fractures among individuals participating in the Childhood Cancer Survivor Study (CCSS).

METHODS

Analyses included 7414 ≥ 5-year survivors of childhood cancer diagnosed between 1970 and 1986 who completed the 2007 CCSS follow-up questionnaire and a comparison group of 2374 siblings. Generalized linear models stratified by sex were used to compare the prevalence of reported fractures between survivors and siblings.

RESULTS

The median ages at follow-up among survivors and siblings were 36.2 years (range, 21.2-58.8 years) and 38.1 years (range, 18.4-62.6 years), respectively, with a median 22.7 years of follow-up after cancer diagnosis for survivors. Approximately 35% of survivors and 39% of siblings reported ≥ 1 fracture during their lifetime. The prevalence of fractures was lower among survivors than among siblings, both in males (prevalence ratio, 0.87; 95% confidence interval, 0.81-0.94; P < .001) and females (prevalence ratio, 0.94; 95% confidence interval, 0.86-1.04; P = .22). In multivariable analyses, increasing age at follow-up, white race, methotrexate treatment, and balance difficulties were associated with increased prevalence of fractures among female survivors (P = .015). Among males, only smoking history and white race were associated with an increased prevalence of fracture (P < .001).

CONCLUSIONS

Findings from this study indicated that the prevalence of fractures among adult survivors did not increase compared with that of siblings. Additional studies of bone health among aging female cancer survivors may be warranted.

Time-dependent alterations in growth and bone health parameters evaluated at different posttreatment periods in pediatric oncology patients

Bone mineral density (BMD) and anthropometric measurements in pediatric cancer patients were evaluated and compared at early and late posttreatment periods. Sixty-six pediatric cancer patients who recovered completely following treatment longer than at least a 6-month period were included in the study. Patients were evaluated cross-sectionally and prospectively with regard to anthropometric measurements and BMD twice; the first being at a mean period of 2.62 ± 1.44 years and the second of 6.55 ± 1.71 years after the completion of treatment. Rates of osteoporosis and osteopenia at first or second evaluation were 25.8% and 39.4% or 10.6% and 19.7%, respectively. Mean BMD z-scores were (-1.26) ± 1.12 [(-4.3)-2.0] and (-0.48) ± 1.25 [(-3.30)-3.40] at first and second evaluations, respectively. BMD findings obtained at second evaluation revealed statistically significant recovery compared with those obtained at first evaluation (P = .001). BMD z-scores were significantly lower in patients who received, as opposed to those who did not receive, radiotherapy (RT) at both evaluations. Anthropometric parameters of patients such as height, weight, and body mass index (BMI) were increased at both evaluations compared with values obtained at diagnosis (P < .05). Height standard deviation score (SDS) decreased at first evaluation compared with that measured at diagnosis, whereas it increased at second evaluation. Conversely, weight SDS and BMI SDS increased (P < .05) at first evaluation compared with that measured at diagnosis, whereas they decreased at second evaluation. The authors conclude that early impairments in anthropometric measurements recover in the long term, whereas BMD is continually reduced in children who recovered from cancer.

Bone mineral density in adult survivors of childhood acute leukemia: impact of hematopoietic stem cell transplantation and other treatment modalities

Femoral and lumbar bone mineral densities (BMDs) were measured in 159 adults enrolled in the Leucémies de l'Enfant et de l'Adolescent program, a French prospective multicentric cohort of childhood leukemia survivors. BMDs were expressed as Z-scores, and multivariate linear regression analyses were used to construct association models with potential risk factors. Mean age at evaluation and follow-up was 23 and 14.7 years, respectively. In the whole cohort, mean femoral Z-score was -0.19 ± 0.08. Two factors were associated with lower femoral BMD transplantation (-0.49 ± 0.15 vs -0.04 ± 0.10 in the chemotherapy group; P = .006) and female sex (-0.34 ± 0.10 vs -0.03 ± 0.13; P = .03). Among patients who received a transplant, the only significant risk factor was hypogonadism (-0.88 ± 0.16 vs -0.10 ± 0.23; P = .04). A slight reduction in lumbar BMD (mean Z-score, -0.37 ± 0.08) was detected in the whole cohort without difference between the transplantation and chemotherapy groups. Among patients who received a transplant, younger age at transplantation was correlated with a low lumbar BMD (P = .03). We conclude that adults who had received only chemotherapy for childhood leukemia have a slight reduction in their lumbar BMD and a normal femoral BMD. Patients who received a transplant with gonadal deficiency have a reduced femoral BMD which might increase the fracture risk later in life.

An osteoporotic hip fracture in a 14-year-old girl undergoing chemotherapy and operated for knee osteosarcoma

Non-weight-bearing, pre- and postsurgical immobilization, neoadjuvant and adjuvant chemotherapy are known to act on bone turnover, causing osteoporosis over short and long time periods. Treatment of fracture insurgence is very difficult because it really depends on being able to choose the right time (i.e., when immunodeficiency is less important). We report a case of spontaneous neck femur fracture during adjuvant chemotherapy in a young girl treated with resection and prosthesis reconstruction for distal femur osteosarcoma. Possible prevention and the correct approach and surgical timing are emphasized considering immunodeficiency following chemotherapy.

Total body bone measurements: a cross-sectional study in children with acute lymphoblastic leukemia during and following completion of therapy

BACKGROUND

Abnormalities in bone mineral density (BMD) occur in children treated for acute lymphoblastic leukemia (ALL). However, BMD estimates have been performed using varied instruments, reference data, and interpretations. This exploratory cross sectional study to evaluate bone mass in children with ALL, uses an algorithm that serially adjusts for variables known to affect pediatric bone measures by dual energy X-ray absorptiometry (DXA), based on models developed in 1,218 healthy children and adolescents.

PROCEDURE

Anthropometry, DXA scans, and factors with possible influence on bone mass were evaluated in 21 ALL patients receiving chemotherapy and 20 in the follow-up phase. Main outcome was treatment group differences in Z-scores for total body bone mineral content (BMC), bone area (Area), and areal BMD (aBMD).

RESULTS

Mean Z-scores for the entire study population for BMC, Area, and aBMD were significantly less than zero. Among possible contributing factors, only calcium intake was a significant co-variate. Comparison between treatment groups showed that least-square mean Z-scores for patients on-therapy for at least 12 months were significantly lower than those off therapy for at least 12 months (P: 0.0008-0.044), except for BMC at last step of the algorithm (adjusted for sex, age, ethnicity, height, weight, and bone area).

CONCLUSIONS

Evaluation of total body DXA by this algorithm is consistent with better general bone status in those off-therapy. However, in this small exploratory study, the lack of significant difference between Z-scores for fully adjusted BMC in on- versus off-therapy groups suggests possible risk of low peak bone mass. Additional longitudinal evaluation is warranted.

Dual-energy X-ray aborptiometry assessment in children and adolescents with diseases that may affect the skeleton: the 2007 ISCD Pediatric Official Positions

The Task Force focusing on the use of dual energy X-ray absorptiometry (DXA) in children and adolescents with diseases that may affect the skeleton reviewed over 300 articles to establish the basis for the Official Positions. A significant number of studies used DXA-based outcome measures to assess the effects of specific interventions and charted the natural history of incremental changes in bone size and mass in specific disease states in children. However, the utility of DXA in clinical practice has not been evaluated systematically, in large part due to the lack of a workable definition for childhood osteoporosis. Thus, in combination with the Official Positions addressing the diagnosis of osteoporosis in children, and the reporting of DXA results in children, this document presents clear guidelines from which clinicians and researchers alike can work. This report delineates a set of disorders in which it is appropriate to use DXA as part of the comprehensive assessment of skeletal health in children and adolescents, and provides guidance concerning the initiation of assessment and the frequency of monitoring. Importantly, this document also highlights significant gaps in our knowledge, emphasizing areas for future research.

Effect of 1,25(OH)2-vitamin D on bone mass in children with acute lymphoblastic leukemia

BACKGROUND

Calcitriol deficit has been described in patients with acute lymphoblast leukemia (ALL). The aim of this randomized case-control trial is to investigate the effectiveness of calcitriol administration during the first year of treatment to protect bone mass. Sixteen children recently diagnosed with ALL, aged 1.7 to 11.5 years, average 5.5, completed the study. Anthropometrical measurements, food intake record, physical activity, and bone pain were registered. Dual energy x-ray absorptiometry was performed at the completion of remission induction chemotherapy (after 1 mo) to measure bone mineral density (BMD) at hip, lumbar spine and whole body, and total bone mineral content and 1 year after. Half of them were randomly assigned to receive calcitriol during 1 year.

STATISTICAL

Kruskal-Wallis, Wilcoxon, Mann-Whitney, and Spearman.

RESULTS

Both groups had similar anthropometric measurements and bone densitometric variables increments. Spine BMD significantly increased in calcitriol supplemented children with lower baseline BMD (r=-0.78 and P<0.05).

CONCLUSIONS

One-year calcitriol administered to recently diagnosed ALL children did not show impact on bone mass. Greater increment in lumbar spine bone mass was observed in patients who received calcitriol and had lower baseline BMD.

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.

Bone mineral density and bone metabolism in children treated for bone sarcomas

In adolescent bone sarcoma patients, bone mass acquisition is potentially compromised at a time in which it should be at a maximum. To evaluate the problem we measured bone mineral density (BMD) and serum markers of bone formation and resorption in a series of pediatric patients with bone tumors. BMD was measured by dual-energy x-ray absorptiometry, at clinical remission, for lumbar spine and the neck of the femur in 38 osteosarcoma and 25 Ewing's sarcoma patients. Mean age was 20.65 and 19.13 y respectively. Serum markers of bone metabolism were: OC, PICP, ICTP, 25-OH vit D and 1,25-(OH)(2) vit D, IGF-I, IGFBP-3 and intact PTH. Serum was sampled throughout anti-tumoral treatments and follow-up. We analyzed 85 samples from 59 osteosarcoma patients and 54 samples from 36 Ewing's sarcoma patients. Patients had decreased lumbar and femoral BMD. The decrease was more pronounced in pubertal patients compared with those who had completed pubertal development at the time of disease diagnosis. Multivariate analysis indicated that sex, age, weight and BMI were significant in lumbar BMD depletion. Weight and BMI were significant in femoral BMD depletion. Serum markers of bone formation (PICP and OC) and resorption (ICTP) were, throughout, lower than reference values. Significant alterations in other markers were also observed. Up to a third of osteosarcoma and Ewing's sarcoma patients in clinical remission had some degree of BMD deficit. The corresponding increased risk of pathologic bone fractures constitutes a reduction in future quality of life.

Density and structural changes in the bone of growing rats after weekly alendronate administration with and without a methotrexate challenge

Alendronate (ALN) and other bisphosphonates have been used successfully in pediatric patients with osteopenia secondary to connective tissue diseases. Loss of growth in height has not been reported, but concerns remain regarding the effect of these potent antiresorptive agents when used in children and adolescents. High-dose methotrexate (MTX) and other chemotherapy drugs have been implicated in osteoporosis and a high fracture incidence in survivors of childhood cancers and are also associated with osteopenia in adult animals. The effect of high dose MTX on bone density during rapid skeletal growth, however, has not been widely studied, nor has the potentially therapeutic effect of bisphosphonates in this setting. We examined the effects of ALN and MTX administration, alone and in combination, on bone density, morphology, mechanical strength, and longitudinal growth in normal growing rats. Sprague-Dawley rats were given ALN once weekly (0.3 mg/kg) from 5 to 11 weeks of age, with and without a course of methotrexate (MTX) given daily in weeks 1 and 3 (0.75 mg/kg/day). Twenty-four animals were randomly divided into four groups: Control (vehicle), ALN alone, ALN + MTX, and MTX alone. After 6 weeks, the femora, tibiae, and lumbar spine were studied by dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, mechanical strength testing, microradiography, light microscopy, and by determination of ash weights and bone lengths. ALN treatment increased bone mineral density (BMD) by 23% to 68%. The largest increases in the femur occurred in the distal third where endochondral bone growth was greatest and included large increases in trabecular bone and total cross-sectional area. ALN + MTX produced similar effects to ALN alone. MTX only reduced BMD by 8% in the vertebrae, but not significantly at other sites. MTX also led to femoral length reductions of 2.9%. The small reductions in BMD due to MTX were overwhelmed by the increases due to ALN, whereas the length loss was unaffected. Transverse density banding corresponding to weekly ALN administrations were clearly evident radiographically throughout the growing skeleton, likely due to decreased resorption and possibly increased mineralization in the bands. ALN or ALN + MTX treatment also led to increases in mechanical strength in the femora. Although MTX administration during growth leads to some BMD reduction, ALN given with MTX eliminates this reduction and in fact bone density and strength increase above control levels.

Bone mineral density decrements and children diagnosed with cancer

This integrative literature review is focused on (1) the prevalence of bone mineral density (BMD) decrements in children treated for acute lymphoblastic leukemia (ALL), and when these decrements are observed; (2) the risk factors associated with the development of decreased BMD and resultant complications in children treated for ALL; (3) the role, if any, that corticosteroids play in decreasing BMD in children treated for ALL; (4) interventions that can potentially manage bone loss in people treated for ALL during childhood or adolescence. The results showed that people who have been diagnosed with ALL can have decrements in BMD. The etiology of BMD decrements can be attributed to multiple factors including genetic endowment, lifestyle behaviors, the leukemia disease process, and treatment exposures especially to corticosteroids and cranial radiotherapy. Male gender, age greater than 10 years, and physical inactivity are associated with BMD decrements in ALL survivors. The role of pediatric oncology nurses in the management of bone disease in children with cancer across the illness trajectory is discussed.

Evaluation of bone mineral density at different phases of therapy of childhood all

In the present study the authors evaluated the status of spinal bone mineral density (BMD) using dual-energy X-ray absorptiometry in a group of 31 children with acute lymphoblastic leukemia, treated by ALL-BFM protocols without irradiation, at different phases of their treatment. These patients were studied (1) within 2 months of diagnosis (group 1, n = 17, median time postdiagnosis 17 days), (2) during chemotherapy (group 2, n = 16, median time on treatment 22 months), and (3) shortly after completion of therapy (group 3, n = 10, median time postchemotherapy 13 months). Twelve patients underwent serial measurements in either of the groups they entered (6 patients of group 1 and 6 patients of group 2). The mean cumulative prednisone dose was 0.8, 4.3, and 5 g/m2 in groups 1, 2, and 3, respectively. A gradual decline of BMD from group 1 through group 3 was observed. The mean value of age- and sex-specific BMD z-score was -0.74 (+/-0.32) in group 1, -1.59 (+/-0.24) in group 2, and -2.03 (+/-0.27) in group 3; there was a statistically significant difference between groups 1 and 3 (p = .022). A BMD z-score < -2 was found in 3 (17%), 4 (25%), and 5 (50%) patients of groups 1, 2, and 3, respectively. In conclusion, a high incidence of reduced bone mass was observed during and shortly after treatment. These findings could have significant consequences in long-term survivors.

Low turnover bone disease in Egyptian children with acute leukemia

The aim of this work was to study bone turnover markers, calcium homeostasis and bone mineral density (BMD) in children with acute leukemia at diagnosis, after induction chemotherapy, and during maintenance therapy to delineate abnormalities present. After evaluation of L2-L4 BMD using dual-energy X-ray absorptiometry in patients with acute myeloid and lymphoid leukemia at presentation and after treatment, the results were compared to 352 healthy age- and sex-matched Egyptian controls. Calcium homeostasis parameters and bone turnover biochemical markers (serum osteocalcin and urinary deoxypyridinoline) were also assayed and the results were compared to 12 healthy age- and sex-matched controls. Osteopenia was observed at diagnosis and during treatment in patients with acute leukemia. At diagnosis osteopenia was observed in 27 patients (62.8%): 10 (23.3%) had non severe osteopenia and 17 (39.5%) had severe osteopenia. This low BMD persisted in those who were followed up. Parathyroid hormone (PTH) (pg/ml) levels demonstrated non significant differences between children with acute leukemia at different stages of therapy and controls, while, 25 (OH) D3 (ng/ml) was significantly lower in acute leukemia patients at different stages of therapy compared to controls (p<0.001). Osteocalcin (ng/ml) is significantly lower in patients at different stages of the disease compared to controls (p<0.001) but there was no significant difference between patients at different stages of therapy. Deoxy-pyridoline cross links showed non-significant difference between the different types of acute leukemia and with controls. Osteopenia is a significant problem in children with acute leukemia at presentation and after chemotherapy. Osteopenia in acute leukemia appears to be of the low turnover type (decreased osteoblastic activity and decreased bone mineralization).

Osteoporosis due to Glucocorticoid Use in Children with Chronic Illness

Osteoporosis is increasingly recognized as a complication of chronic childhood illnesses, particularly when glucocorticoids (GCs) are necessary for treatment. Elucidation of the mechanisms leading to bone fragility in these settings requires disentanglement of the relative contributions of myriad risk factors, including disease activity, muscle weakness, immobilization, delayed growth and puberty, compromised nutrition, and osteotoxic medications. Over the years, bone mass and density evaluations by dual energy X-ray absorptiometry (DXA) have become popular for assessing bone health in children; however, such measurements are difficult to interpret because of the confounding effect of bone size and the lack of DXA-based densitometric criteria for defining osteoporosis in childhood. Recently, a new diagnostic approach for evaluation of densitometric data in children has been suggested, driven by Frost's mechanostat theory. A diagnostic algorithm based on the mechanostat theory of bone-muscle development is proposed for the characterization of bone disease in children with chronic illness. In addition to DXA-based assessments, techniques such as peripheral quantitative computerized tomography and ilial histomorphometry, for which there are pediatric reference data, are gaining ground in the characterization of skeletal changes due to chronic illness. Although these diagnostic techniques expand our understanding of osteoporosis in children, they do not replace clinical assessment. Concrete clinical evidence for GC-induced bone fragility can be seen in spinal changes due to vertebral compression, with spinal morphometry emerging as an essential, but frequently overlooked, tool in the evaluation of children's bone health. Presently, osteoporosis treatment in the chronic illness setting remains experimental and should be restricted to clinical studies. Following an understanding of the natural history of GC-induced osteoporosis in children, randomized, placebo-controlled prevention and intervention trials will be the next step toward the development of clinical practice guidelines.

Improvement in bone mineral density and body composition in survivors of childhood acute lymphoblastic leukemia: a 1-year prospective study

OBJECTIVES

Abnormalities in bone mineral density (BMD), body composition, and bone metabolism have been reported in children who were treated for acute lymphoblastic leukemia (ALL) during and after completion of therapy. However, these studies are cross-sectional, and no longitudinal data are available in a large group of patients after completion of therapy. In the present study, 1-year longitudinal changes in BMD, body composition, and bone metabolism were evaluated in children with ALL during the first 3 years after completion of therapy without cranial irradiation.

METHODS

BMD of total body (TB; g/cm(2)), areal and apparent volumetric lumbar spine (L2-L4), lean body mass, and percentage of body fat were measured by dual-energy x-ray absorptiometry in 37 children (median age: 7.9 years; range: 4.7-20.6 years) who were treated for ALL at a median age of 3.3 years (range: 1.1-16.6 years), after a median time of 2.2 years after the completion of treatment, and after a 1-year follow-up period. Two control subjects (n = 74) who were matched for gender, age, and pubertal stage were also longitudinally investigated for body composition for 1 year. Usual serum biochemical markers of calcium metabolism and bone turnover were measured in patients during the study period.

RESULTS

A slight decrease in TB BMD was found after a median time of 2.2 years after the completion of therapy for ALL in childhood. Patients showed a significantly lower median TB BMD when evaluated <1.5 years as compared with those at >or=1.5 years since completion of therapy. At the time of first evaluation, the percentage of body fat mass was significantly higher and patients were physically less active than their matched control subjects. Although, as expected, during the 1 year of follow-up both groups showed an annual increment in their BMD measurements, a significantly higher increase in TB BMD was observed in patients in comparison with control subjects. During this same period, the increase in the percentage of body fat mass was slightly lower in ALL patients as compared with control subjects. At the end of the follow-up year, BMD, body-composition parameters, and physical activity of ALL patients were similar to those observed in matched control subjects. Serum biochemical markers of bone turnover were normal at both evaluations.

CONCLUSIONS

A significant increase in TB BMD and a tendency to a lesser increase in percentage of body fat mass were observed during the study period in ALL patients as compared with chronological age-, gender-, and pubertal stage-matched control subjects. These findings suggest a positive effect of long-term completion therapy and increase in physical activity on BMD, body composition, and bone metabolism in patients who have been treated for ALL.

Reduced bone mineral density in childhood chronic idiopathic thrombocytopenic purpura treated with high-dose methylprednisolone

PURPOSE

To evaluate whether repeated courses of high-dose methylprednisolone (HDMP) affect the lumbar spine bone mineral density (BMD) in children with chronic idiopathic thrombocytopenic purpura (ITP).

MATERIALS AND METHODS

This study included 24 patients with chronic ITP and 149 healthy controls. The patients were allocated into three groups according to the number of HDMP courses (30 mg/kg per day as a single dose for 7 days); group 1 (10 patients), group 2 (9 patients), and group 3 (5 patients) had received less than 5, 6-10, and more than 10 courses, respectively. Lumbar spine BMD and body composition were measured using dual energy X-ray absorptiometry of lumbar spine (L2-L4), and volumetric bone mineral density (vBMD) values were calculated and compared with the controls. The z score of the vBMD was also calculated and compared in the patients of each other groups. Serum markers of the bone turnover were measured to exclude other factors that could effect BMD.

RESULTS

The vBMD values of the patients, corrected BMDs for age, were significantly lower than the values of controls (P = 0.018). It was significantly lower in group 3 than groups 1 and 2 (P = 0.005 and P = 0.006, respectively), but there was no statistically significant difference between groups 1 and 2 (P = 0.87). The vBMD z scores were significantly lower in group 3 than in groups 1 and 2 (P = 0.003 and P = 0.004, respectively), and also in group 2 than in group 1 (P = 0.034). There were a weak negative correlation between the cumulative dose of HDMP and vBMD (r = -0.39, P = 0.054), and strong negative correlation between the cumulative dose of HDMP and vBMD z score (r = -0.63, P = 0.001).

CONCLUSION

Children with chronic ITP are at risk for decreased BMD because of the repeated courses of HDMP; especially more than 2100 mg of cumulative dose. We therefore recommend that BMD should be monitored in patients with chronic ITP who received repeated courses of HDMP.

Skeletal morbidity in childhood acute lymphoblastic leukemia

PURPOSE

Treatment for acute lymphoblastic leukemia (ALL) in childhood results in a reduction in bone mineral density (BMD). Whether there is a recovery of this lost bone mass in survivors of ALL is not known. We sought to determine if changes in BMD are common long-term sequelae in children with ALL.

METHODS

Bone mineral densitometry of the lumbar spine and femoral neck was performed on 106 patients. The results were compared with those of age-matched normal controls. The effect of treatment was examined in those with low BMD compared with the remainder of the study group.

RESULTS

When data were tested with respect to age, sex, and age and sex, no difference was observed in BMD between survivors of childhood ALL and controls. In the subgroup of patients with low BMD, the difference was not related to age, age at diagnosis, or years since diagnosis. Low BMD of the spine was not explained by radiotherapy (RT), methotrexate (MTX) dose, or corticosteroid dose. Low BMD of the femur was not explained by RT. However, those with low femoral BMD were more likely to have received high-dose MTX or higher-dose corticosteroids compared with the remainder of the group.

CONCLUSION

It appears that survivors of childhood ALL as a whole recover normal BMD. However, those patients who received a total MTX dose of greater than 40000 mg/m(2) or a total corticosteroid dose of greater than 9000 mg/m(2) may not recover normal BMD and therefore should be screened for decreased BMD of the femoral neck.

Bone density in survivors of childhood cancer

Advances in combination chemotherapy, radiation therapy, surgery, and bone marrow transplantation have resulted in markedly improved survival rates for many children with cancer. Advancements in therapy, however, have led to new concerns, namely long-term consequences of effective treatments. Young adult and adult survivors of childhood cancer are at risk for a number of disorders related to therapy. Specifically, the young adult who has survived cancer, attendant treatments, and their complications is at risk for factors that can lead to suboptimal acquisition of peak bone mass. These factors include chronic illness, nutritional deficiencies, limited physical activity, and treatment with glucocorticoids, multiagent chemotherapy, and radiation. The long-term adverse effects of these therapies on endocrine systems, especially sex steroid and growth hormone deficiencies, are additional risk factors for some patients. After a brief review of the processes associated with acquisition of peak bone mass in the young adult, this article examines the impact of cancer and cancer therapy on bone mineral density in survivors of childhood cancer.

Effects of chemotherapeutic agents on the function of primary human osteoblast-like cells derived from children

Studies in children treated with chemotherapy suggest that chemotherapeutic agents have deleterious effects on bone metabolism. We therefore evaluated the in vitro effects of clinically relevant concentrations of chemotherapeutic agents on the synthesis of type I collagen, alkaline phosphatase (AP) activity, and mineralization by primary human osteoblast-like (HOB) cells derived from children. Because serum 1,25-dihydroxyvitamin D(3) concentrations may be reduced during treatment with chemotherapy, the effect of chemotherapeutic agents on HOB cells cultured in the presence or absence of 1,25-dihydroxyvitamin D(3) was also evaluated. Type I collagen synthesis was reduced by all agents (P < 0.01) other than methotrexate, whereas the relative AP activity was increased (P < 0.01) by all agents. The relative number of cells staining intensely for AP after culture with agents increased (P < 0.05), and AP mRNA expression was increased (P < 0.01) with vincristine. 1,25-Dihydroxyvitamin D(3) ameliorated (P < 0.01) the depletion of HOB cell numbers by chemotherapeutic agents. Furthermore, vincristine and daunorubicin inhibited 1,25-dihydroxyvitamin D(3)-mediated AP activity (P < 0.01). We conclude that chemotherapeutic agents can adversely affect HOB cell function, and we speculate that this observation may account, in part, for the osteopenia observed during and after treatment of children with chemotherapy.

Radiation-therapy effects on bone density

Only limited data are available on the effects of radiation-therapy on the mineral content of the bone of children treated for malignancy. The incidence of osteopenia varies between 8 and 23%, but confounding factors were the use of chemotherapy and the effects of prophylactic cranial irradiation. The factors influencing bone atrophy are no more clearly defined in adults treated for cancer by high dose local radiation-therapy. Pathological observed in patient tissues, indicates a clear role for vascular changes in the development of osteopenia, although there remains some uncertainty as to the effects of osteoblast cell loss. Reduced blood flow in bone is clearly dose-related in experimental animal studies and after single doses of >20 Gy changes in bone mineral content have been found. However, this was only at late times (>/=30 weeks) after irradiation. The relationship between these changes and bone strength remains unproven because of the limited nature of many of the animal studies. Radiation dose fractionation data for rib-fracture in breast cancer patients suggests an alpha/beta ratio is in the range 1.8-2.8 Gy, comparable to values obtained for other late responding normal human tissues.

Renal function following hematological stem cell transplantation in childhood

Renal function greatly influences mortality rates in the early phase following hematological stem cell transplantation (HSCT) in childhood, as well as the quality of life in long-term survivors. Nevertheless, the number of studies in pediatric populations is limited and some important aspects of kidney function after HSCT have only been elucidated in adults. The incidence of acute renal failure (ARF) immediately after HSCT in pediatric patients is between 25% and 50%, with 5%-10% of children requiring renal replacement therapy. Doubling of serum creatinine is associated with a twofold increase in mortality. However, the need for dialysis leads to a further increase in mortality rates to 80%-90%. Specific renal syndromes appear at different times following HSCT, revealing a similar pattern in children and adult patients. In both children and adults, impaired renal function associated with liver impairment (hepatorenal syndrome) is the most important cause for ARF. Therapeutic approaches have not been able to reduce the frequency or to improve outcome so far. In adults surviving long term, bone marrow transplant (BMT) nephropathy is the most frequent renal complication, although a considerable variation in incidence (up to 70%) has been published, partly due to various definitions and manifestations. Little is known about the long-term outcome of renal function in patients treated with HSCT in childhood. However, chronic renal failure has been reported in 0%-28%, but no end-stage renal failure has been published so far. Tubular function following HSCT is rarely investigated, although its impact on long-term survivors of BMT in childhood might be of some importance, especially for growth and bone metabolism.

Endocrine complications in pediatric patients with acute lymphoblastic leukemia

Endocrine complications of therapy for acute lymphoblastic leukemia (ALL) are common and are potentially debilitating both during and after therapy. Growth velocity slows during therapy for ALL, especially during the first year; however, children who do not receive cranial irradiation usually reach normal adult height. While growth hormone deficiency generally occurs in patients who have received 24Gy of cranial irradiation, it may also develop in those treated with lower doses (18Gy) of cranial radiation or with only high-dose methotrexate. Obesity commonly occurs during therapy and persists after completion of therapy. Osteopenia can occur early during therapy for ALL and can persist for many years. Adrenal insufficiency should be suspected in any child who has recently received glucocorticoid therapy, and stress doses of steroid should be administered in the event of metabolic stress. Screening of urine is useful for early detection of hyperglycemia during therapy with glucocorticoids and L-asparaginase. The syndrome of inappropriate secretion of anti-diuretic hormone is usually associated with vincristine therapy and may be aggravated by concurrent use of azole antifungals. Finally, patients who have received 18 or 24Gy of cranial irradiation may have clinical or subclinical deficiencies of thyroid hormones.

Bone mineral assessment with tibial ultrasonometry and dual-energy X-ray absorptiometry in long-term survivors of acute lymphoblastic leukemia in childhood

Acute lymphoblastic leukemia (ALL) in childhood is a serious disease that can affect growth and the attainment of maximal peak bone mass. The latter has recently been recognized as a risk factor for the development of osteoporosis later in life. To determine long-term effects of the disease itself and its treatment, we assessed the bone status of a group of long-term survivors of childhood ALL, all treated with high doses of steroids (dexamethasone) and methotrexate and without cranial irradiation. All 21 subjects enrolled in this cross-sectional study were diagnosed to have non-high-risk precursors acute lymphoblastic leukemia (12 boys and 9 girls, mean age 16.5 yr, range 12.2-25.4 yr). Standard deviation (SD) scores were calculated using a tibial ultrasound device and spinal dual-energy X-ray absorptiometry (DXA) device as bone assessment techniques. SD scores of those two different bone assessment techniques were compared. The mean SOS (speed of sound) SD scores (SDS) of the tibia (mean 0.26, standard deviation [sd] 1.00) were not significantly different from our reference value of 0. There was no significant difference between the SOS SDS in boys and girls. With DXA, no significant difference was seen between the mean BMD SDS and the reference data and no significant difference in BMD between boys and girls was found. The individual mean SDS for bone mineral density (BMD) of lumbar spine are 0.24 (sd 1.02), total body 0.17 (sd 1.00), and apparent BMD (BMAD) 0.07 (sd 1.09). Spearman's correlation between mean SOS SDS and mean BMD of lumbar spine was 0.47, mean SOS SDS and mean BMAD SDS was 0.43, and mean SOS SDS and mean BMD of total body was 0.49. These correlations were significant at the 0.05 level (two tailed). Despite high-dose dexamethasone and methotrexate used for treatment of these children with ALL, no long-term side effects on the bone mineral status of the subjects, measured with DXA or tibial ultrasonometry, could be determined.

Bone mass after treatment of malignant lymphoma in childhood

BACKGROUND

Sex hormone deficiency, growth hormone deficiency, skeletal irradiation, and treatment with corticosteroids or methotrexate may all cause reduction in bone mass after treatment for childhood malignant lymphoma. Previous studies of the bone mass of childhood cancer survivors often lacked adequate local reference data, and survivors of malignant lymphoma were never analyzed separately.

PROCEDURE

The bone mass of survivors of childhood Hodgkin disease (n = 23) or non-Hodgkin lymphoma (n = 21) was measured by dual-energy X-ray absorptiometry a median of 11 years after diagnosis (range 2-25). Results were compared with local data on 463 healthy controls.

RESULTS

Adjusted for gender and age, the mean whole-body bone mineral content and bone mineral areal density were slightly, but significantly, reduced (0.5 and 0.4 SD lower than predicted). The reduced bone mineral content was associated with a significantly reduced height, whereas the size-adjusted bone mass (bone mineral content for bone area) did not differ significantly from that of controls. Lower height was related to male gender and to cranial, thoracic, and lumbar spine irradiation. Whole-body bone mineral content and bone mineral density were lower in persons treated with lumbar spine irradiation and whole-body bone mineral content was higher in nine women receiving sex hormone replacement therapy or oral contraceptives. Whole-body bone mass was not related to the cumulated doses of corticosteroids or methotrexate.

CONCLUSIONS

Eleven years after diagnosis of childhood Hodgkin disease or non-Hodgkin lymphoma, the whole-body bone mass of survivors was only slightly reduced and the size-adjusted bone mass was normal.

Osteoporosis in survivors of acute lymphoblastic leukemia

Osteoporosis is currently receiving increasing attention as an important late effect in survivors of childhood cancer and its treatment because of their quality of life and its negative effect on the survivors' ability to perform developmentally appropriate activities. Survivors of childhood cancer are especially vulnerable because they are affected during childhood and adolescence, a time when peak bone mass should be achieved. This paper reviews decreased bone density in acute lymphoblastic leukemia (ALL), which is the most common childhood cancer and has a cure rate approaching 80%. Osteopenia/osteoporosis has been observed in all phases of the disease: at diagnosis, during treatment, and throughout the post-treatment period for as long as 20 years. Among the findings that have been described are musculoskeletal pain, disturbed gait, fractures, kyphosis, lordosis, and growth failure. Risk factors not specifically related to ALL include smoking, ingestion of carbonated beverages, and family history of "brittle bone" or fractures. Patients should be counseled in regard to diet, exercise, smoking cessation, and avoidance of carbonated beverages. There are a number of options for specific drug therapy; however, the administration of bisphosponates to children and adolescents must be approached with caution. Research is needed to determine how extensive the problem is and how to best prevent and treat the osteopenia/osteoporosis associated with ALL.

Osteoporosis in childhood: bone density of children in health and disease

Bone mineral density in later life largely depends on the peak bone mass achieved in adolescence or young adulthood. A reduced bone density is associated with increased fracture risk in adults as well as in children. Pediatricians should therefore play an important role in the early recognition and treatment of childhood osteoporosis. Juvenile idiopathic osteoporosis and osteogenesis imperfecta are examples of primary osteoporosis in childhood. However, osteoporosis is more frequently a complication of a chronic disease or its treatment. This paper provides an overview of bone and bone metabolism in healthy children and the use of diagnostic tools, such as biochemical markers of bone turnover and several bone densitometry techniques. Furthermore, a number of diseases associated with osteoporosis in childhood and possible treatment strategies are discussed.

Normal bone mineral density after treatment for childhood acute lymphoblastic leukemia diagnosed between 1991 and 1998

OBJECTIVE

We investigated whether previous reports of reduced bone mineral density after management for childhood acute lymphoblastic leukemia (chALL) were confirmed in a more recently treated cohort.

STUDY DESIGN

In a cross-sectional study 75 subjects who were given the diagnosis of chALL between January 1, 1991, and December 31, 1997 (69% standard, 31% high risk), at Denver Children's Hospital and who were 11 to 82 months post-diagnosis with no history of relapse, secondary malignancy, or transplant underwent whole body areal bone mineral densitometry (BMD(A) expressed as age- and sex-standardized z scores), a food frequency questionnaire, and a weight-bearing activity survey.

RESULTS

Overall, the mean whole body BMD(A) z score was normal (+0.22 +/- 0.96). A significant positive association was found with whole body BMD(A) z score and years elapsed since the beginning of maintenance (linear regression coefficient = +0.2 Deltaz score/year; 95% CI = 0.09 to 0.3) after adjustment was done for risk status/age category, history of cranial radiation, and total days hospitalized. No association was found with high risk/older age at diagnosis, nutrient intake, chemotherapy dosage, or weight-bearing activity.

CONCLUSION

Contrary to previous reports in which cranial radiation and longer hospitalizations were prominent components of therapy, our study suggests that more recently treated patients with chALL do not have persistent abnormalities of bone mineral density after completion of therapy.

Bone mineral density, body composition, and height in long-term survivors of acute lymphoblastic leukemia in childhood

BACKGROUND

Childhood leukemia has increasing numbers of survivors, so more emphasis is being placed on long-term effects. The ALL-6 protocol of the Dutch Childhood Leukemia Study Group involved high-dose dexamethasone and methotrexate and no cranial irradiation. Therefore, we studied the long-term effects on bone mineral density (BMD), body composition, and growth in survivors of non-high-risk ALL treated with the ALL-6 protocol.

PROCEDURE

Twenty-three subjects (12.2-25.4 years) participated in this cross-sectional study. Mean follow-up was 9.6 years (range 7.9-11.4 years). BMD of lumbar spine (LS) and total body (TB) and body composition were measured by dual energy X-ray absorptiometry; results are expressed as standard deviation scores (SDS). Bone mineral apparent density (BMAD(LS)) was calculated to correct for bone size. A questionnaire was administered to determine physical activity, calcium intake, and medical history.

RESULTS

Mean SDS for BMD(LS), BMD(TB), and BMAD(LS) were normal. None of the subjects had BMD below -2 SDS; one subject had BMAD(LS) below -2 SDS. Mean SDS for lean body mass, percentage fat, and height were not significantly different from zero. Calcium intake correlated positively with BMD. Nine subjects reported traumatic fractures (eight during or shortly after therapy).

CONCLUSIONS

Ten years after ALL-6 treatment, no long-term side effects on height, BMD, or body composition were found in this small group of patients, despite high-dose dexamethasone and methotrexate. This study suggests that ALL treatment without cranial irradiation might not be associated with long-term side effects on growth and BMD.

The effect of chemotherapy on the growing skeleton

With the increasing use of high dose (poly)chemotherapy schedules in the treatment of childhood cancer it is particularly important to know the adverse effects of these treatments. Growth is a complex mechanism affected not only by chemotherapy but also by the malignancy itself as well as nutritional status, the use of corticosteroids and (cranial) radiation. In vitro and animal studies are often the most useful in determining the effect of a single chemotherapeutic agent on the growing skeleton. In vitro studies have shown doxorubicin, actinomycin D and cisplatin to have a direct effect on growth plate chondrocytes that in animals results in decreased growth and final height. Clinical studies with multiagent chemotherapy have demonstrated that antimetabolites decrease bone growth and final height. Childhood cancer survivors are at risk of a reduced bone mineral density, mainly due to methotrexate, ifosfamide and corticosteroids. This reduced bone mineral density persists into adult life and may increase bone fracture risk at an older age.

Impaired development of bone mineral density during chemotherapy: a prospective analysis of 46 children newly diagnosed with cancer

Osteopenia and osteoporosis are becoming increasingly recognized in children with cancer, though reasons for these changes are poorly understood. The purpose of the present study was to evaluate longitudinal changes in bone mineral density (BMD) and bone turnover in newly diagnosed children with a malignancy. Lumbar spine (L2-L4) and femoral neck bone mineral density (BMDareal, g/cm2) was measured by dual-energy X-ray absorptiometry in 46 children (age 2.9-16.0, median 8.0 years; 15 leukemias, 12 lymphomas, 19 solid tumors) at diagnosis, and after 6 months from the baseline. The apparent volumetric bone mineral density (BMDvol) was calculated to minimize the effect of bone size on BMD. Serum levels of osteocalcin (OC), type I collagen carboxy-terminal propeptide (PICP), and type I collagen carboxy-terminal telopeptide (ICTP) were analyzed at diagnosis, and during a 6-month follow-up. A significant decrease in lumbar BMDvol (-2.1%, p < 0.05), and in femoral BMDareal (-9.9%, p = 0.0001) and BMDvol (-8.5%, p = 0.0001) was observed after 6 months when compared with baseline measurements. The markers of bone formation (PICP, OC) were significantly decreased, and the marker of bone resorption (ICTP) was significantly increased at diagnosis as compared with normal values. By the end the follow-up, the levels of PICP and OC were normalized, whereas the level of ICTP continued to increase indicating that there was a negative balance in bone turnover. A deficient accumulation of bone mass might predispose children with a malignancy to impaired development of peak bone mass. A controlled study determining the benefits of an early intervention on bone turnover should be considered in these patients.