Cross-sectional study of bone mineral density in adult survivors of solid pediatric cancers

Bone Mineral Density in Survivors of Childhood Cancer: A Meta-Analysis

CONTEXT

There is an increasing population of childhood cancer survivors (CCS) at risk for treatment-related toxicities, including skeletal morbidities. Bone mineral density (BMD) is a proxy for bone health and reductions are associated with osteoporosis and fractures.

OBJECTIVE

To investigate bone health in CCS by conducting a systematic review and meta-analysis of BMD after completed treatments.

DATA SOURCES

We searched Medline, Embase, Cochrane, and Web of Science in May 2019 and updated in May 2023.

STUDY SELECTION

Studies reporting BMD Z-scores measured with dual-energy x-ray absorptiometry in CCS after treatment completion.

DATA EXTRACTION

We performed a pooled analysis of studies reporting BMD Z-scores and thereafter we analyzed studies comparing BMD in survivors and healthy controls. All analyses were performed based on the site of BMD measurement.

RESULTS

Of 4243 studies, 84 were included (N = 8106). The mean time off-treatment across the studies ranged from 2 months to 24 years. The overall pooled mean Z-score was -0.57 (95% confidence interval [CI] -0.59 to -0.55) in the whole-body, -0.84 (95% CI -0.86 to -0.83) in the lumbar spine, -0.79 (95% CI -0.81 to -0.77) in the femoral neck and -0.14 (95% CI -0.18 to -0.11) in the total hip. When comparing survivors with controls, BMD was significantly lower in survivors at all sites.

LIMITATIONS

English publications, study-level meta-analysis.

CONCLUSIONS

We showed a significant reduction of BMD Z-scores in CCS. Given the increased fracture risk already within -1 SD, these results emphasize the need for BMD surveillance and secondary prevention in CCS.

Prevalence of delayed puberty and low bone density in patients with epidermolysis bullosa: Insight from a large single center's experience

BACKGROUND

Epidermolysis bullosa (EB) is a group of rare genetic skin conditions that result in skin fragility. EB can be quite severe with chronic inflammation and malnutrition impairing growth and pubertal development. These factors have potential consequences for skeletal health. We aimed to determine the prevalence of delayed puberty and low bone mineral density (BMD) for age in children and young adults with EB.

METHODS

Electronic medical records (EMR) of patients with confirmed EB <30 years of age at time of initial encounter at Cincinnati Children's Hospital Medical Center between January 1, 2010 and September 30, 2020 were reviewed. Natural language processing software was used to categorize pubertal status of patients with EB as early, normal or delayed. BMD was measured by dual energy x-ray absorptiometry and categorized as low if height adjusted Z-score was <-2.0 using age, sex and race specific reference ranges.

RESULTS

29% of individuals with EB had low BMD with most cases occurring prior to 10 years of age. Of patients who reached adolescence, 23% failed to develop any signs of puberty in the normal range (before age 13 in females or 14 in males) and BMD Z-scores further declined in these individuals.

CONCLUSION

Delayed puberty is an under-recognized comorbidity of individuals with EB, especially in those with recessive dystrophic EB, and can have a significant impact on BMD.

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.

Clinical phenotype and musculoskeletal characteristics of patients with aggrecan deficiency

Aggrecan is a proteoglycan within the physeal and articular cartilage. Aggrecan deficiency, due to heterozygous mutations in the ACAN gene, causes dominantly inherited short stature and, in many patients, early-onset osteoarthritis and degenerative disc disease. We aimed to further characterize this phenotypic spectrum with an emphasis on musculoskeletal health. Twenty-two individuals from nine families were enrolled. Histories and examinations focused on joint health, gait analysis, joint specific patient reported outcomes, and imaging studies were performed. All patients had dominantly inherited short stature, with the exception of a de novo mutation. Short stature was worse in adults versus children (median height -3.05 SD vs. -2.25 SD). ACAN mutations were not always associated with bone age advancement (median advancement +1.1 years, range 0 to +2 years). Children had subtle disproportionality and clinically silent joint disease-25% with osteochondritis dissecans (OD). Adults had a high prevalence of joint symptomatology-decline in knee function, disability from spinal complaints, and lower physical activity on outcome measures. Osteoarthritis (OA) and OD was detected in 90% of adults, and orthopedic surgeries were reported in 60%. Aggrecan deficiency leads to short stature with progressive decline in height SD, mild skeletal dysplasia, and increasing prevalence of joint pathology over time. Optimal musculoskeletal health and quality of life can be attained with timely identification of pathology and intervention.

Bone mineral density changes in a free vascularised fibular graft in the distal femoral bone after osteosarcoma in a 10-year-old boy: a 7-year follow-up

A 10-year-old boy presented with continuous reports of pain located to the left knee. Imaging revealed a sclerotic process in the left distal femur, and biopsies were consistent with chondroblastic osteosarcoma. As part of standard treatment the patient underwent neoadjuvant chemotherapy followed by limb sparring surgery and adjuvant chemotherapy. The entire tumour was excised and femoral bone reconstruction was performed with a double barrel free vascularised fibular graft. Bone mineral density (BMD) can be decreased in childhood survivors of cancer. The patient was followed for 7 years with dual-energy X-ray absorptiometry scans in order to assess BMD and graft adaption. Despite two accidental fractures to the graft region local and global BMD underwent an overall increase. Approximately 7 years after tumour resection the patient had a global Z-score of 0.2, which is considered within normal range.

Outcomes following intravenous bisphosphonate infusion in pediatric patients: A 7-year retrospective chart review

INTRODUCTION

Intravenous bisphosphonates (IV BP) have been used to treat children with osteoporosis for many years. Favorable side effect profile and improvements in bone mineral density (BMD) have been demonstrated in patients with osteogenesis imperfecta (OI), a primary form of osteoporosis in pediatrics. Less is known about the safety of IV BP in children with secondary osteoporosis or glucocorticoid-induced osteoporosis (GIO). We aimed to determine the prevalence of both acute and long-term side effects and assess the efficacy of IV BP treatment to increase bone mineral density in pediatric patients with varying presentations of compromised bone health.

METHODS

We conducted a retrospective chart review of pediatric patients (<21 years old) treated for osteoporosis with intravenous pamidronate (PAM) or zoledronic acid (ZA) at Cincinnati Children's Hospital Medical Center from 2010 to 2017. Patient demographics, diagnosis, infusion type and dose, acute phase reactions (APR), electrolyte abnormalities, and bone density measurements were collected from the electronic medical records. Diagnoses were grouped into 3 categories: primary osteoporosis, secondary osteoporosis, and GIO. Descriptive characteristics and adverse events were compared among categories. Change in bone mineral density (BMD) over time was compared among groups.

RESULTS

123 patients (56% male) received 942 infusions (83% PAM and 17% ZA). APR was reported in 7% of all infusions and more common in secondary osteoporosis (16%, p < 0.0001). There was a higher percentage of acute adverse events after the first infusion (27% vs 5%, p < 0.0001). Hypocalcemia following IV BP infusions occurred in 7% (27/379) of infusions and was significantly associated with ZA use (p = 0.04). Severity of hypocalcemia was generally mild, requiring intravenous calcium in 3% (13/379) of infusions. Hypophosphatemia occurred frequently, however rarely required intravenous supplementation. In 468 patient years of IV BP exposure, there were no reports of osteonecrosis of the jaw (ONJ) nor atypical femoral fracture (AFF). Lumbar spine (LS) aBMD Z-score 1 year after IV BP initiation increased overall for all groups (p < 0.0001) but did not significantly differ for those who did or did not fracture following IV BP treatment.

CONCLUSIONS

APR due to intravenous BP treatment for pediatric osteoporosis were infrequent and generally mild. APR were more likely to occur in patients with secondary osteoporosis, a group who may require closer monitoring. A higher proportion of hypophosphatemia occurred in the patients with GIO. Long-term serious adverse events including ONJ and AFF were not identified in our patient population. LS aBMD Z-score increased following initiation of IV BP. However, the change in BMD was not associated with risk of fracture during the follow-up interval. These data provide reassurance and suggest that IV BP can be safely used in pediatric patients with osteoporosis.

Amifostine Suppresses the Side Effects of Radiation on BMSCs by Promoting Cell Proliferation and Reducing ROS Production

This study is aimed at investigating the effect of amifostine (AMI) on rat bone marrow stromal stem cells (BMSCs) exposed to 2 Gy radiation. The BMSCs were divided into four groups, namely, group A that received 0 Gy radiation, group B that received 0 Gy radiation and AMI, group C that received 2 Gy radiation, and group D that received 2 Gy radiation and AMI. The proliferation, apoptosis, and distribution of BMSCs in the cell cycle, along with their osteogenesis ability, adipogenesis ability, and ROS production, were subsequently examined. The levels of ALP, PPARγ, P53, and TNFα were determined by Western blotting. The results demonstrated that the proliferation of BMSCs and the levels of ALP in group C were much lower than those in group A. The production of ROS and levels of PPARγ, P53, and TNFα in the group that received 2 Gy radiation were much higher than those in group A. Furthermore, the production of ROS and the levels of PPARγ, P53, and TNFα were much lower in group D than in group C. Additionally, the levels of ALP and extent of cell proliferation were much higher in group D than in group C. The results demonstrated the potential of AMI in reducing the side effects of radiation in BMSCs and in treatment of bone diseases caused by radiation.

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.

Use of dual energy X-ray absorptiometry in pediatric patients

Dual Energy X-ray Absorptiometry (DXA) is a vital tool for assessing bone health in patients at risk for fragility fractures. In pediatric patients, this technology is used in conjunction with clinical fracture history to diagnosis osteoporosis and monitor treatment response. Childhood and adolescence is characterized by linear growth and bone mass accrual; thus there are important differences in the interpretation of bone measurements obtained by DXA in these young patients. This review aims to explore the current indications for DXA use and interpretation of DXA in the pediatric age group using currently available reference databases. Limitations of DXA in pediatric patients, specifically in children with short stature, will be explored. We will review several pathophysiologic mechanisms that may lead to low bone density in children, discussing representative diseases and the recommendations for monitoring bone health with DXA in these conditions. Finally, we will highlight new methods by which DXA imaging can gather additional information on bone health in children and may improve our ability to predict fractures and osteoporosis.

Low bone mineral density and fractures are highly prevalent in pediatric patients with spinal muscular atrophy regardless of disease severity

Patients with Spinal Muscular Atrophy (SMA) are at risk for poor bone health. The prevalence of fractures, low areal bone mineral density (aBMD; Z-score ≤-2.0) of the lateral distal femur and of osteoporosis by SMA subtype is not known. We aimed to describe the natural history of bone health in patients with SMA prior to bisphosphonate treatment. We reviewed data from 85 eligible patients with SMA ages 12 months to 18 years, seen at a single institution between January 2005 and July 2016. Fracture history was reported at annual clinic visits. aBMD was obtained from dual energy x-ray absorptiometry scans of the lumbar spine, total body, and lateral distal femur. 85% of patients had aBMD Z-scores ≤-2.0 SD and were progressively lower with worsening SMA severity. Longitudinal aBMD Z-scores of the lateral distal femur decreased with age. Fractures occurred in 38% (32/85) of patients with the femur being the most common location (25 of 57 fractures). Thirteen percent of patients fulfilled criteria for osteoporosis. Low aBMD and femur fractures are highly prevalent in all SMA subtypes from a young age; however, few patients met the criteria for osteoporosis. Poor bone health may be an under-recognized comorbidity of SMA.

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.

Parathyroid hormone attenuates radiation-induced increases in collagen crosslink ratio at periosteal surfaces of mouse tibia

As part of our ongoing efforts to understand underlying mechanisms contributing to radiation-associated bone fragility and to identify possible treatments, we evaluated the longitudinal effects of parathyroid hormone (PTH) treatment on bone quality in a murine model of limited field irradiation. We hypothesized PTH would mitigate radiation-induced changes in the chemical composition and structure of bone, as measured by microscope-based Raman spectroscopy. We further hypothesized that collagen crosslinking would be especially responsive to PTH treatment. Raman spectroscopy was performed on retrieved tibiae (6-7/group/time point) to quantify metrics associated with bone quality, including: mineral-to-matrix ratio, carbonate-to-phosphate ratio, mineral crystallinity, collagen crosslink (trivalent:divalent) ratio, and the mineral and matrix depolarization ratios. Irradiation disrupted the molecular structure and orientation of bone collagen, as evidenced by a higher collagen crosslink ratio and lower matrix depolarization ratio (vs. non-irradiated control bones), persisting until 12weeks post-irradiation. Radiation transiently affected the mineral phase, as evidenced by increased mineral crystallinity and mineral-to-matrix ratio at 4weeks compared to controls. Radiation decreased bone mineral depolarization ratios through 12weeks, indicating increased mineral alignment. PTH treatment partially attenuated radiation-induced increases in collagen crosslink ratio, but did not restore collagen or mineral alignment. These post-radiation matrix changes are consistent with our previous studies of radiation damage to bone, and suggest that the initial radiation damage to bone matrix has extensive effects on the quality of tissue deposited thereafter. In addition to maintaining bone quality, preventing initial radiation damage to the bone matrix (i.e. crosslink ratio, matrix orientation) may be critical to preventing late-onset fragility fractures.

Vitamin D and Bone Minerals Status in the Long-term Survivors of Childhood Acute Lymphoblastic Leukemia

Background:

Low vitamin D and diminished bone minerals with the potential for fractures are one of the nonapparent late effects of acute lymphoblastic leukemia (ALL). Chemotherapy and radiation were known as two important risk factors. We evaluated these late effects in ALL survivors who were treated with chemotherapy or chemo plus cranial radiation therapy.

Methods:

In a case–control study, 33 of ALL survivors who were treated with chemotherapy (Group A), and 33 subjects who were treated with chemoplus cranial radiation (Group B) were compared against 33 matched age, sex, and pubertal stage of their healthy siblings (Group C). Standard anthropometric data were collected as well as Tanner staging for puberty, number of fractures since treatment, serum calcium (Ca), phosphorus (P), magnesium (Mg), alkaline phosphatase, parathyroid hormone, and 25-hydroxyvitamin D (25(OH) D). The independent t-test, one-way ANOVA, Chi-square test, and Tukey's test were used to analyze the data.

Results:

The findings indicated that the mean serum levels of 25(OH) D in ALL survivors (i.e. Groups A and B) with age mean score of 11.2 years and 12.3 years, average treatment length: 3.25 years and average time after treatment completion: 4 years, was lower compared to the controls group (12.94 ± 6.69, 14.6 ± 8.1, 20.16 ± 10.83, respectively, P < 0.001) but no significant difference was observed between Group A and B in this regard (P > 0.05). Other clinical and laboratory parameters had no significant differences between the survivors and control. Vitamin D deficiency (<20 ng/ml) was observed in 27% of group A and 24% of group B and vitamin D insufficiency (20–30 ng/ml) in 72.7% and 69.6% survivors of Group A and B and 48.5% of controls group (P = 0.003).

Conclusions:

ALL treatment is associated with the increase in prevalence of vitamin D insufficiency in the childhood ALL survivors and since the low vitamin D level potentially increases the risk of low bone density, subsequent malignancies, and cardiovascular disease in the survivors, close follow-up of such patients are highly recommended to prevent the stated complications.

Do long term survivors of ewing family of tumors experience low bone mineral density and increased fracture risk?

BACKGROUND

Multimodal treatment regimens for Ewing's sarcoma have led to survival rates approaching 70% of patients with no metastases at diagnosis. However, these treatments have long-term side effects. Low bone mineral density (BMD) and risk of fractures can occur owing in part to chemotherapy and limited mobility from local control of the primary tumor.

QUESTIONS/PURPOSES

We performed this study to answer the following questions: (1) Do long-term survivors of the Ewing family of tumors sustain low BMD? (2) Which factors are associated with BMD in these patients? (3) Do they experience fractures? (4) Are BMD and fractures associated with each other?

METHODS

We queried our institutional registry to identify all known survivors of Ewing tumors who were treated before 2005. Of 100 such patients, 67 (67%) responded to a postal survey to participate in this study, and an additional 11 (11%) patients were excluded according to prespecified criteria. In the remaining 56 long-term survivors (27 females, 29 males; mean±SD age at followup, 32±10 years; mean followup, 15±7 years), BMD was measured by dual-energy x-ray absorptiometry and history of fractures was assessed using a questionnaire. Associations were tested using univariate and multivariate models by stepwise variable selection procedure, including Bonferroni correction.

RESULTS

Thirty-one of 56 (56%) patients had a pathologic BMD. Seven (13%) had osteoporosis and 24 (43%) had osteopenia. Factors related to low BMD after Bonferroni correction were the length of time between surgery and followup and the BMI at followup. Twenty-one patients reported 29 fractures. With the numbers available, BMD levels were not associated with fractures.

CONCLUSIONS

We could not confirm some potentially important predictors for fractures to be associated with clinical events of interest. However, the data are valuable as hypothesis-generating pilot data for future, multicenter prospective studies. If BMD changes cannot explain the propensity of fractures, there may be other bone characteristics like microarchitectural changes of bone to more accurately explain the effect.

LEVEL OF EVIDENCE

Level IV, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.

Bone mineral density in pediatric survivors of Hodgkin and non-Hodgkin lymphomas

PURPOSE

To assess skeletal mass in survivors of childhood Hodgkin disease (HD) and non-Hodgkin lymphoma (NHL) 1-5 years after treatment, and to identify potential risk factors influencing bone mineral density (BMD).

PATIENTS/METHODS

This cross-sectional study was conducted in a cohort of 43 survivors (HD=31; NHL=12); mean age: 16.21 ± 4.4. Total body bone mineral content (TBMC) and density (TBBMD), and lumbar spine density (LSBMD) were determined using dual-energy X-ray absorptiometry.

RESULTS

Three of all 43 patients developed low BMD. No significant differences in height, weight, and/or BMD Z-scores were found between HD and NHL survivors, children who received and did not receive radiotherapy, and the groups with different chemotherapeutic blocks. No differences were noted between the Z-scores of BMC (mean ± SD: 0.31 ± 1.29 vs. -0.089 ± 0.61, p=0.165), TBBMD (mean ± SD: -0.32 ± 1.21 vs. -0.27 ± 0.91, p=0.76), or the LSBMD (mean ± SD: -0.183 ± 1.54 vs. -0.17 ± 0.87, p=0.637) in subgroups, in accordance with time after therapy (subgroup I<2 years and subgroup II>2 years after treatment). In HD survivors, age at diagnosis only affected the TBBMD Z-score (a decrease of 0.127 in total BMD Z-score per each year, R²=0.999, p<0.001).

CONCLUSIONS

Childhood lymphoma survivors demonstrate no significant deficits in bone mass and tend to maintain their BMD within the normal range when presenting during one to five years' follow-up. However, this specific group requires longitudinal investigation to assess the pattern of peak bone mass achievement and the risk of future bone loss.

Raman spectroscopy demonstrates prolonged alteration of bone chemical composition following extremity localized irradiation

INTRODUCTION

Radiotherapy to the appendicular skeleton can cause an increased risk of developing catastrophic fractures with delayed bone healing or non-union, and may subsequently require multiple procedures and amputation. Biomechanical studies suggest that irradiated bone is more brittle, but the cause is unclear and cannot be explained by changes to bone structure or quantity, suggesting that there are crucial changes in irradiated bone material properties. Raman spectroscopy provides a means to assess the chemical properties of the mineral and matrix constituents of bone, which could help explain post-radiation embrittlement. In this study we use a murine tibial model with focal irradiation and perform Raman spectroscopy to test the hypothesis that changes in bone chemistry following irradiation is consistent with reduced bone quality and persists in the long term after irradiation.

METHODS

Female BALB/F mice aged 12weeks were subjected to unilateral, localized hindlimb irradiation in 4 daily 5Gy fractions (4×5Gy) totaling 20Gy, and were euthanized at 1, 4, 8, 12, and 26weeks post-irradiation (n=6/group). The irradiated (right) and non-irradiated contralateral control (left) tibiae were explanted and assessed by non-polarized and polarized Raman spectroscopy over the proximal cortical bone surface. Raman parameters used included the mineral/matrix ratio, mineral crystallinity, carbonate/phosphate ratio, collagen cross-link ratio, and depolarization ratio.

RESULTS

Significantly increased collagen cross-link ratio and decreased depolarization ratio of matrix were evident at 1week after irradiation and this persisted through 26weeks. A similar significant decrease was observed for depolarization ratio of mineral at all time points except 8 and 26weeks. At 4weeks after irradiation there was a significantly increased mineral/matrix ratio, increased mineral crystallinity, and decreased carbonate/phosphate ratio compared to controls. However, at 12weeks after irradiation these parameters had moved in the opposite direction, resulting in a significantly decreased mineral/matrix ratio, decreased crystallinity and increased carbonate/phosphate ratio compared to controls. At 26weeks, mineral/matrix, crystallinity and carbonate/phosphate ratios had returned to normal.

DISCUSSION

In this mouse model, Raman spectroscopy reports both bone mineral and collagen cross-link radiation-induced abnormalities that are evident as early as one week after irradiation and persists for 26weeks. The picture is one of extensive damage, after which there is an attempt at remodeling. We hypothesize that pathological cross-links formed by radiation damage to collagen are poorly resorbed during the altered remodeling process, so that new tissue is formed on a defective scaffold, resulting in increased bone brittleness.

Zoledronic acid prevents loss of trabecular bone after focal irradiation in mice

Radiation therapy for soft tissue sarcomas and metastatic disease can adversely affect bone, leading to late-onset fragility fractures. Adjunct administration of bisphosphonates has been postulated as means of minimizing these adverse effects. Using a murine model of focal hindlimb irradiation, we examined the potential for zoledronic acid treatment to minimize the deleterious effects of localized radiotherapy (RTx) on bone. Mice received a single, unilateral hindlimb exposure of 20 Gy. Beginning 4 days prior to irradiation, and at 1, 2 and 3 weeks post-irradiation, animals were treated with zoledronic acid or saline/vehicle injections. Areal bone mineral density was assessed at 4 days, and 2, 4 and 12 weeks post-irradiation by dual-energy X-ray absorptiometry (DXA). Micro-computed tomography and axial compression testing were used to quantify changes in morphological and mechanical properties of femurs at 4 and 12 weeks post-irradiation. Radiation had differential effects on cortical and trabecular bone, increasing cortical bone mineral content (BMC), cortical bone volume (BV) and trabecular separation (Tb.Sp) while decreasing trabecular number (Tb.N) by 12 weeks after localized radiotherapy. Administration of zoledronic acid increased hindlimb areal bone mineral density in both the presence and absence of radiotherapy, increased cortical bone mineral content and bone volume, increased trabecular bone volume (BV/TV), increased trabecular number, increased trabecular thickness (Tb.Th), and decreased trabecular separation compared to irradiated and vehicle control femurs. Despite these improvements in morphology with zoledronic acid, no biomechanical advantage was observed. Further work is needed to define the role of bisphosphonates in prevention of post-irradiation fragility fractures.

Endocrine health conditions in adult survivors of childhood cancer: the need for specialized adult-focused follow-up clinics

BACKGROUND

Survival rates among childhood cancer survivors (CCS) have enormously increased in the last 40 years. However, this improvement has been achieved at the expense of serious late effects that frequently involve the endocrine system.

AIM

To evaluate the cumulative incidence of endocrine diseases in a cohort of long-term CCS.

MATERIALS AND METHODS

We analyzed the clinical data of 310 adults, followed for a median time of 16.0 years after the first cancer diagnosis. The monitoring protocols applied to each patient were personalized on the basis of cancer diagnosis and previous treatments, according to the Children's Oncology Group guidelines.

RESULTS

The cumulative incidence of endocrine late effects steadily increased over time. At the last follow-up visit available, 48.46% of females and 62.78% of males were affected by at least one endocrine disease. The most common disorders were gonadal dysfunction, primary hypothyroidism, and GH deficiency (GHD). The main risk factors for endocrine disease were male sex (hazard ratio (HR)=1.45, 95% confidence interval (95% CI) 1.05-1.99), radiotherapy (HR=1.91, 95% CI 1.28-2.84), hematopoietic stem cells transplantation (HR=3.11, 95% CI 2.23-4.34), and older age at cancer diagnosis (HR=1.89, 95% CI 1.25-2.85). Male sex was associated with a higher risk of gonadal disorders, whereas radiotherapy specifically increased the risk of GHD and thyroid dysfunction.

CONCLUSIONS

Endocrine disorders among CCS have a high prevalence and increase over time. Thus, endocrinologists need to cope with an increasing demand for health care in a field that is still little developed and that, in perspective, could also be extended to some selected types of adult cancer survivors.

Bone mineral density deficits in childhood cancer survivors: Pathophysiology, prevalence, screening, and management

As chemotherapy and other sophisticated treatment strategies evolve and the number of survivors of long-term childhood cancer grows, the long-term complications of treatment and the cancer itself are becoming ever more important. One of the most important but often neglected complications is osteoporosis and increased risk of fracture during and after cancer treatment. Acquisition of optimal peak bone mass and strength during childhood and adolescence is critical to preventing osteoporosis later in life. However, most childhood cancer patients have multiple risk factors for bone mineral loss. Cancer itself, malnutrition, decreased physical activity during treatment, chemotherapeutic agents such as steroids, and radiotherapy cause bone mineral deficit. Furthermore, complications such as growth hormone deficiency and musculoskeletal deformity have negative effects on bone metabolism. Low bone mineral density is associated with fractures, skeletal deformity, pain, and substantial financial burden not only for childhood cancer survivors but also for public health care systems. Thus, it is important to monitor bone health in these patients and minimize their risk of developing osteoporosis and fragility fractures later in life.

Changes in health status among aging survivors of pediatric upper and lower extremity sarcoma: a report from the childhood cancer survivor study

OBJECTIVE

To evaluate health status and participation restrictions in survivors of childhood extremity sarcomas.

DESIGN

Members of the Childhood Cancer Survivor Study cohort with extremity sarcomas who completed questionnaires in 1995, 2003, or 2007 were included.

SETTING

Cohort study of survivors of extremity sarcomas.

PARTICIPANTS

Childhood extremity sarcoma survivors (N=1094; median age at diagnosis, 13y (range, 0-20y); current age, 33y (range, 10-53y); 49% male; 87.5% white; 75% had lower extremity tumors) who received their diagnosis and treatment between 1970 and 1986.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Prevalence rates for poor health status in 6 domains and 5 suboptimal social participation categories were compared by tumor location and treatment exposure with generalized estimating equations adjusted for demographic/personal factors and time/age.

RESULTS

In adjusted models, when compared with upper extremity survivors, lower extremity survivors had an increased risk of activity limitations but a lower risk of not completing college. Compared with those who did not have surgery, those with limb-sparing (LS) and upper extremity amputations (UEAs) were 1.6 times more likely to report functional impairment, while those with an above-the-knee amputation (AKA) were 1.9 times more likely to report functional impairment. Survivors treated with LS were 1.5 times more likely to report activity limitations. Survivors undergoing LS were more likely to report inactivity, incomes <$20,000, unemployment, and no college degree. Those with UEAs more likely reported inactivity, unmarried status, and no college degree. Those with AKA more likely reported no college degree. Treatment with abdominal irradiation was associated with an increased risk of poor mental health, functional impairment, and activity limitation.

CONCLUSIONS

Treatment of lower extremity sarcomas is associated with a 50% increased risk for activity limitations; upper extremity survivors are at a 10% higher risk for not completing college. The type of local control influences health status and participation restrictions. Both of these outcomes decline with age.

Modifiable risk factors associated with bone deficits in childhood cancer survivors

BACKGROUND

To determine the prevalence and severity of bone deficits in a cohort of childhood cancer survivors (CCS) compared to a healthy sibling control group, and the modifiable factors associated with bone deficits in CCS.

METHODS

Cross-sectional study of bone health in 319 CCS and 208 healthy sibling controls. Bone mineral density (BMD) was measured by dual-energy x-ray absorptiometry (DXA). Generalized estimating equations were used to compare measures between CCS and controls. Among CCS, multivariable logistic regression was used to evaluate odds ratios for BMD Z-score ≤ -1.

RESULTS

All subjects were younger than 18 years of age. Average time since treatment was 10.1 years (range 4.3 - 17.8 years). CCS were 3.3 times more likely to have whole body BMD Z-score ≤ -1 than controls (95% CI: 1.4-7.8; p = 0.007) and 1.7 times more likely to have lumbar spine BMD Z-score ≤ -1 than controls (95% CI: 1.0-2.7; p = 0.03). Among CCS, hypogonadism, lower lean body mass, higher daily television/computer screen time, lower physical activity, and higher inflammatory marker IL-6, increased the odds of having a BMD Z-score ≤ -1.

CONCLUSIONS

CCS, less than 18 years of age, have bone deficits compared to a healthy control group. Sedentary lifestyle and inflammation may play a role in bone deficits in CCS. Counseling CCS and their caretakers on decreasing television/computer screen time and increasing activity may improve bone health.

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

SUMMARY

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Bone mineral density in newly diagnosed children with neuroblastoma

BACKGROUND

Neuroblastoma is the second most common extracranial malignant tumor of childhood and the most common solid tumor of infancy which is characterized by bone metastasis. Previous reports on bone mineral density (BMD) in patients with leukemia and solid malignancies concentrate on long-term survivors and on the effect of chemotherapeutic agents and irradiation. Also, evaluation of BMD in neuroblastoma was reported in few studies which were conducted upon adult survivors of childhood cancer. Previous studies on both acute leukemia and lymphoma patients suggested that the disease process itself played a role in decrease BMD.

METHODS

We evaluated 27 patients with newly diagnosed neuroblastoma for both lumbar (L2-L4) BMD and total BMD using dual energy X-ray absorptiometery (DXA) scan to highlight the effect of neuroblastoma as a disease process on BMD as this disease characterized by bone metastasis.

RESULTS

Three out of the 27 patients showed low bone mass in both lumbar and total BMD studies.

CONCLUSION

Low bone mass may occur in early disease process of neuroblastoma and it is important to consider BMD assessment during the early course of the disease as well as the long-term survivors as a part of the patient screening in suspected cases.

Early decrements in bone density after completion of neoadjuvant chemotherapy in pediatric bone sarcoma patients

Background

Bone mineral density (BMD) accrual during childhood and adolescence is important for attaining peak bone mass. BMD decrements have been reported in survivors of childhood bone sarcomas. However, little is known about the onset and development of bone loss during cancer treatment. The objective of this cross-sectional study was to evaluate BMD in newly diagnosed Ewing's and osteosarcoma patients by means of dual-energy x-ray absorptiometry (DXA) after completion of neoadjuvant chemotherapy.

Methods

DXA measurements of the lumbar spine (L2-4), both femora and calcanei were performed perioperatively in 46 children and adolescents (mean age: 14.3 years, range: 8.6-21.5 years). Mean Z-scores, areal BMD (g/cm²), calculated volumetric BMD (g/cm³) and bone mineral content (BMC, g) were determined.

Results

Lumbar spine mean Z-score was -0.14 (95% CI: -0.46 to 0.18), areal BMD was 1.016 g/cm² (95% CI: 0.950 to 1.082) and volumetric BMD was 0.330 g/cm³ (95% CI: 0.314 to 0.347) which is comparable to healthy peers. For patients with a lower extremity tumor (n = 36), the difference between the affected and non-affected femoral neck was 12.1% (95% CI: -16.3 to -7.9) in areal BMD. The reduction of BMD was more pronounced in the calcaneus with a difference between the affected and contralateral side of 21.7% (95% CI: -29.3 to -14.0) for areal BMD. Furthermore, significant correlations for femoral and calcaneal DXA measurements were found with Spearman-rho coefficients ranging from ρ = 0.55 to ρ = 0.80.

Conclusions

The tumor disease located in the lower extremity in combination with offloading recommendations induced diminished BMD values, indicating local osteopenia conditions. However, the results revealed no significant decrements of lumbar spine BMD in pediatric sarcoma patients after completion of neoadjuvant chemotherapy. Nevertheless, it has to be taken into account that bone tumor patients may experience BMD decrements or secondary osteoporosis in later life. Furthermore, the peripheral assessment of BMD in the calcaneus via DXA is a feasible approach to quantify bone loss in the lower extremity in bone sarcoma patients and may serve as an alternative procedure, when the established assessment of femoral BMD is not practicable due to endoprosthetic replacements.

Prevalence of abnormal bone density of pediatric patients prior to blood or marrow transplant

Osteoporosis and osteopenia are long-term side effects of bone marrow transplant (BMT). The purpose of this study was to determine the prevalence of bone mineral density (BMD) abnormalities in pediatric patients prior to BMT. Forty-four pediatric patients were evaluated with DEXA scans. The average Z-score was -0.37. Thirty-six percent had abnormal BMD. Sixty-seven percent of ALL patients had abnormal BMD. Patients with non-malignant diseases were significantly more likely to have abnormal BMD. Patients with ALL had more defects than solid tumor patients. Females had more defects than males. These results demonstrate BMD defects are common in children prior to BMT, especially in patients with ALL.

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.

Pediatric Hodgkin lymphoma survivors at negligible risk for significant bone mineral density deficits

BACKGROUND

We hypothesized that pediatric Hodgkin lymphoma (HL) survivors would have bone mineral density (BMD) deficits compared to their peers because of osteotoxic chemotherapy during the time of greatest BMD accretion.

METHODS

We retrospectively reviewed records of HL survivors returning for follow-up between 1990 and 2002. Of the 133 eligible survivors, 109 who underwent quantitative computed tomography (QCT) comprised the study group. QCT-determined BMD Z-scores were correlated with patient characteristics and therapeutic exposures by Wilcoxon rank sum or Chi-square tests. Logistic regression models were used to explore risk factors for diminished BMD.

RESULTS

The study cohort was half male (50.5%) and 85.3% reported their race as white. Participants were representative of all survivors potentially eligible for study, except that more study participants were female, had hypothyroidism, and had received cyclophosphamide. Median age at diagnosis was 15.1 years (range, 3.1-20.7 years); median time between diagnosis and QCT was 7.5 years (range, 5.0-12.4 years). The proportion of HL survivors with BMD below the mean did not significantly differ from the general population (P = 0.503). However, those with BMD -1.5 SD and BMD -2.0 SD or lower (14.7% and 7.3%, respectively) exceeded that in the general population (6.7% and 2.3%, respectively; P < 0.001 for both degrees of severity). Males, diagnosed at 14 years or older, were at 6.5 times higher risk than females (OR 95% CI: 1.24-34.14; P = 0.027) for BMD deficits.

CONCLUSIONS

Overall, pediatric HL survivors had negligible BMD deficits. Male gender was associated with an increased risk of developing BMD deficits.

Cancer treatment-related bone disease

Bone health may be impaired in many patients being treated for cancer. Primary tumors that reside in or form metastases to bone can result in compromised skeletal integrity. It has also been increasingly recognized that patients undergoing therapies for treatment of cancer are at higher risk of bone loss. These include androgen-deprivation therapy for prostate cancer and aromatase inhibitor therapy for breast cancer, among others. Hypogonadism induced by many of these cancer treatments results in bone loss and increases the risk of osteoporosis and fractures. Progress has been made in identifying the role of oral and intravenous bisphosphonates to prevent bone loss in these patients. This review discusses bone loss associated with cancer treatments, with a focus on breast cancer, prostate cancer, and survivors of childhood malignancies.

Is the treatment for childhood solid tumors associated with lower bone mass than that for leukemia and Hodgkin disease?

BACKGROUND

Cancer disease and its therapy (e.g., chemotherapeutic agents such as glucocorticoids, methotrexate, antymetabolities, cranial and local irradiation) may severely disturb normal growth, bone mineral acquisition, and skeletal development because most individuals go through the stages of rapid growth when childhood cancer is diagnosed.

PROCEDURES

To identify factors associated with reduced bone mineral density (BMD) in survivors of childhood cancer the authors examined 114 patients (70 males) who had been treated for acute lymphoblastic leukemia (ALL; n = 43), Hodgkin disease (HD; n = 35), and solid tumors (ST; n = 36) twice. Median age at diagnosis was 8.4 years; at the consecutive examinations it was 12.8 and 16.3 years, respectively. To assess bone density we used dual-energy x-ray absorptiometry (DXA).

RESULTS

In the first examination, patients with a history of steroid therapy had higher total and spine BMD and higher BMI (body mass index) than those who were not given steroids. At the end of the follow-up, no differences were found in BMD between subgroups, although BMI was still higher in both ALL and HD patients than in those with ST.

CONCLUSIONS

Patients treated for solid tumors have reduced bone mass. Low BMI and local irradiation seem to be the factors responsible for reduced BMD in children treated for ST. The use of steroids does not disturb bone mass accumulation in patients treated for childhood malignancies. However, a long-term effect of cancer treatment on osteoporosis risk remains to be determined.

Bone mineral density deficits in survivors of childhood cancer: long-term follow-up guidelines and review of the literature

The development of curative therapy for most pediatric malignancies has produced a growing population of childhood cancer survivors who are at increased risk for a variety of health problems resulting from their cancer or its treatment. Because of the fact that many treatment-related sequelae may not become clinically apparent until the survivor attains maturity or begins to age, the ability of primary care providers to anticipate late effects of treatment is essential for providing timely interventions that prevent or correct these sequelae and their adverse effects on quality of life. Altered bone metabolism during treatment for childhood cancer may interfere with attainment of peak bone mass, potentially predisposing to premature onset of and more severe complications related to osteopenia and osteoporosis. Bone mineral deficits have been reported after treatment for a variety of pediatric malignancies and represent morbidity that can be reduced or prevented through lifestyle changes and attention to other common cancer-related sequelae such as hypogonadism. The Children's Oncology Group long-term follow-up guidelines for survivors of childhood, adolescent, and young adult cancers provide risk-based surveillance recommendations that are based on expert opinion and review of the scientific literature for potential late effects of pediatric cancer therapy including osteopenia. This review summarizes the existing literature that has defined characteristics of cancer survivors at risk for bone mineral deficits and contributed to the surveillance and counseling recommendations outlined in the Children's Oncology group long-term follow-up guidelines.

Skeletal complications after bone marrow transplant in childhood

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

Low bone mass in children with malignant lymphoma

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

Cancer treatment-induced bone loss

PURPOSE OF REVIEW

Patients treated for cancer may be at risk for osteoporosis and fracture. Evaluation and treatment of patients with cancer treatment-induced bone loss should lead to fewer fractures. This review will help clinicians learn to identify, evaluate and treat cancer patients at risk.

RECENT FINDINGS

Survivors of childhood cancers and patients made hypogonadal by treatment for breast or prostate cancer are clearly at risk for osteoporosis and fracture. Use of aromatase inhibitors rather than tamoxifen for breast cancer will likely lead to more osteoporosis. Bisphosphonates prevent bone loss in many patients at risk.

SUMMARY

For many cancer patients, treatment with calcium, vitamin D, and bisphosphonates will likely decrease the consequences of cancer treatment-induced bone loss, namely fractures.

Pediatric dual-energy X-ray absorptiometry: technique, interpretation, and clinical applications

This article reviews the dual-energy x-ray absorptiometry (DXA) technique, its interpretation, and clinical applications with emphasis on the considerations unique to pediatrics. Specifically, the use of DXA in children requires the radiologist to be a "clinical pathologist," monitoring the technical aspects of the DXA acquisition, a "statistician" knowledgeable in the concepts of Z-scores and least significant changes, and a "bone specialist," aware of the DXA findings in a large number of clinical diseases, providing the referring clinician with a meaningful context for the numeric result obtained with DXA.

Pediatric DXA: clinical applications

Normal bone mineral accrual requires adequate dietary intake of calcium, vitamin D and other nutrients; hepatic and renal activation of vitamin D; normal hormone levels (thyroid, parathyroid, reproductive and growth hormones); and neuromuscular functioning with sufficient stress upon the skeleton to induce bone deposition. The presence of genetic or acquired diseases and the therapies that are used to treat them can also impact bone health. Since the introduction of clinical DXA in pediatrics in the early 1990s, there has been considerable investigation into the causes of low bone mineral density (BMD) in children. Pediatricians have also become aware of the role adequate bone mass accrual in childhood has in preventing osteoporotic fractures in late adulthood. Additionally, the availability of medications to improve BMD has increased with the development of bisphosphonates. These factors have led to the increased utilization of DXA in pediatrics. This review summarizes much of the previous research regarding BMD in children and is meant to assist radiologists and clinicians with DXA utilization and interpretation.

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.

Adverse Late Effects of Childhood Cancer and Its Treatment on Health and Performance

More than 12,000 newly diagnosed cases of cancer occur each year in the United States among children ages 20 years or younger, and the current 5-year survival rate is near 80%. An estimated 228,000 among adults 47 years or younger and currently living in the United States had a diagnosis of cancer during childhood or adolescence. Here, we review long-term adverse effects of childhood cancer and its treatment with an emphasis on physical performance and health. We also briefly review existing guidelines that may be used to develop appropriate exercise and diet interventions for childhood cancer survivors. We suggest that there is a need for development of evidence-based, risk-based guidelines and interventions for health promotion among long-term childhood cancer survivors, particularly for those whose physical activity limitations interfere with chances for optimizing their bodies' potential in today's society.

Long-term effects of treatments for childhood cancers

PURPOSE OF REVIEW

The late effects of current treatments for childhood cancer increase the risk of morbidity and mortality and diminish the quality of life in long-term survivors. We selectively review the negative late cardiac, endocrine, and neurological effects of childhood cancer and its treatments and comment on current research and recommendations for the care of long-term survivors of childhood cancer.

RECENT FINDINGS

Progressive cardiotoxicity has been established. Late cardiac effects can be mitigated with the concomitant use of dexrazoxane with anthracycline. When radiotherapy is used multiple organ systems must be monitored for known late effects dependent on the location. Proper diet, physical activity, and obesity are topics that must be addressed in survivors. Late neurocognitive effects impact intelligence quotient, behavior, and achievement. Systematic follow-up with appropriate clinical screening and testing is important in diagnosing and potentially preventing late effects of cancer therapy.

SUMMARY

The new paradigm for defining successful cancer therapy is the balance between oncologic efficacy and toxicity/late effects. The complexity of late effects necessitates a multidisciplinary approach to long-term care of these patients. The high frequency, delayed onset, and potential severity of late effects demand increased and lifelong monitoring of these individuals.

Advances in the diagnosis and treatment of osteoporosis

Although severely low bone density is relatively rare in the pediatric population, it can be a significant problem in many patients with chronic illness. As peak bone formation occurs during adolescence, it is crucial that pediatricians and other care providers for this patient population recognize the significance of attainment of adequate bone. Dietary intake of vitamin D and calcium should be optimized, and correction of underlying causes of poor bone density should occur whenever possible. Assessment of bone density is difficult, as each technology available has problems, and none of the technologies are well-associated with fracture risk in pediatric patients. Once diagnosis of severely low bone density is established, treatment options are limited and poorly studied. The benefits of bisphosphonate therapy appear to outweigh the risks in patients with low bone density and frequent fragility fractures, and it appears that most improvement with bisphosphonates occurs within the first 2 to 4 years. Evidence, however, is emerging that once off therapy, bone turnover remains decreased for at least several years. During that time, improvements in bone density are decreased. Many questions remain regarding duration of therapy with bisphosphonate therapy and the long-term effects on the children who receive this medication. Anabolic therapies may become important in the future, but there is currently extremely limited information regarding their use in pediatrics.

A pilot study of heel ultrasound to screen for low bone mass in children with leukemia

The optimal method to assess pediatric bone mass remains controversial. Dual x-ray absorptiometry (DXA) is commonly used but quantitative ultrasound is less expensive, free of ionizing radiation, and predicts fractures as well as DXA does, in adults. Broadband ultrasound attenuation (BUA) was determined using a portable calcaneal ultrasonometer and, compared with DXA derived areal bone mineral density (BMD) values in 42 young patients (ages 4.5 to 20.3 y) with leukemia. Reduced BMD was defined as a DXA z score of <-1. Mean z scores for lumbar spine BMD were significantly lower than zero (-0.77+/-1.23 SD, P=0.0004). Mean z scores for whole body BMD were also significantly lower than different from 0 (-0.34+/-1.04 SD, P=0.05). Calcaneal BUA was highly correlated with DXA measurement of lumbar, whole body, and femoral neck BMD. BUA was significantly associated with the probability of having a reduced lumbar BMD z score (P=0.03) and having a reduced whole body z score of (P=0.03). Area under the receiver operator characteristic curves for model including BUA predicting reduced bone density by DXA were 0.77 and 0.86 for lumbar and whole body z score cutoffs, respectively. Our data suggest that calcaneal BUA may serve as a reliable screening tool to detect reduced bone mass in pediatric patients with leukemia.