Bone mineral status during and after therapy of childhood cancer: an increasing population with multiple risk factors for impaired bone health

Bone Loss in Pediatric Survivors of Acute Lymphoblastic Leukemia

Objective

Bone mineral density (BMD) in children may be negatively affected by acute lymphoblastic leukemia (ALL) or its treatment protocol. The aim of our study was to evaluate bone health by measuring BMD after ALL treatment.

Materials and Methods

The age, anthropometric measurements, and lumbar spine BMDs were recorded in 39 pediatric survivors of ALL, with no history of relapse, secondary malignancy, or transplantation. The lumbar spine BMD was measured by dual energy x-ray absorptiometry. The BMD risk factors, pubertal status, age at diagnosis, risk category, the time interval from the completion of the chemotherapy, and cranial radiotherapy were investigated. Serum calcium, phosphate, alkaline phosphates, magnesium, parathormone, and 25-hydroxy vitamin D levels were determined.

Results

The mean BMD value was calculated as 0.668±0.176 g/cm². Osteopenia and osteoporosis were detected in nine patients (23.1%) and three patients (7.7%), respectively, according to previously published data of healthy age- and sex-related Turkish children's BMD values. The mean age at diagnosis of patients with ALL, having the Z-score above -1 was lower than in patients having bone defect (Z score <-1).

Conclusion

Early detection and intervention strategies to optimize bone health are essential in pediatric patients with ALL.

Mobilization patterns of children on a hematology/oncology inpatient ward

BACKGROUND

Children being treated for cancer are admitted to the hospital for treatment of their disease or complications of therapy. Periods of bed rest during hospitalization can cause impairments detrimental to children with cancer who endure many side effects of therapy. Little is known about how these children mobilize while admitted to the hospital. The purpose of this study was to examine how children admitted to a hematology/oncology ward are mobilizing and analyze factors associated with delayed or infrequent mobility.

PROCEDURE

A retrospective chart review was conducted on 228 charts with data recorded on documented mobilization and referrals to physiotherapy. Primary outcome was related to mobility including timing, frequency, type, and nature of mobilization.

RESULTS

Almost half of children (43%) mobilized between 3 and 5 days per week, with median time to first mobilization being 2 days (interquartile range 1-3). Caregivers assisted with mobilization 91% of the time. Children isolated to their room and those reporting fever had a statistically significant decrease in the percent of admission days involving mobilization (mean difference 15 and 8%, respectively) than those not isolated and without fever. Children who were isolated also mobilized 1 day later (P = 0.016) than children who were not isolated. Percentage of time in isolation was positively correlated with timing (P = 0.04) and negatively correlated with frequency of mobilization (P < 0.001).

CONCLUSION

Most children admitted to the hospital for treatment of oncologic or hematologic conditions were noted to mobilize early, but frequency of mobilization could be improved. Periods of time in isolation appear to negatively affect mobilization.

Pediatric Survivors of Retinoblastoma Are at Risk for Altered Bone Metabolism After Chemotherapy Treatment Early in Life

Survivors of childhood cancer frequently suffer from endocrine late effects, which are, at least partly, attributed to toxic effects of chemotherapy. Treatment of retinoblastoma typically involves chemotherapy at a very young age. The authors conducted a cross-sectional study to assess bone health in a pediatric cohort of 33 survivors of retinoblastoma (mean age: 4.4 years) who had undergone chemotherapy treatment at an especially young age (mean age: 0.76 years). Of these patients, 14 had unilateral and 19 bilateral retinoblastoma. Polychemotherapy consisted of treatment with cyclophosphamide, etoposide, vincristine, and carboplatin. Ten patients had undergone external beam radiotherapy. Clinical and biochemical parameters of growth, pubertal development, and bone health were obtained. A vitamin D deficiency was found in 51.7% of the patients, and 13.7% of patients displayed severe vitamin D deficiency. Secondary hyperparathyroidism and altered readings for bone formation or resorption markers were present in 15%. Nine percent reported bone pain or experienced fractures of the long bones after primary diagnosis. No difference between children with bilateral and unilateral disease or irradiated versus nonirradiated children was observed. The parameters of thyroid function, growth, and pubertal development were within age-appropriate norms in almost all children. In conclusion, altered parameters of bone health can be present in survivors of retinoblastoma at a young age and warrant regular follow-up in these children. The endocrine hypothalamic-pituitary axes, however, were not impaired at this early age in this group of survivors of retinoblastoma.

Validity of anthropometric measurements for characterizing obesity among adult survivors of childhood cancer: A report from the St. Jude Lifetime Cohort Study

BACKGROUND

Childhood cancer survivors (CCSs) are at risk for obesity. The purpose of this project was to determine which clinical measures of body composition are most accurate among CCSs in comparison with dual-energy x-ray absorptiometry (DXA).

METHODS

The agreement between the body mass index (BMI), skinfold percent body fat, and waist-to-height ratio (WHtR) and DXA was evaluated among 1361 CCSs (mean age, 32.4 ± 7.7 years) 10 or more years after the diagnosis. The sensitivity and specificity of BMI, skinfold, and WHtR obesity classifications were calculated with respect to DXA. Log-binomial regression, stratified by sex, was used to evaluate treatment-related factors for misclassification as nonobese by BMI, skinfolds, and WHtR.

RESULTS

The mean body fat values were 23.3% ± 7.7% (males) and 32.3% ± 8.1% (females) for skinfolds and 26.9% ± 7.4% (males) and 38.4% ± 7.7% (females) for DXA. Pearson correlations between skinfolds and DXA were high (R = 0.83 for males, R = 0.84 for females). Skinfolds incorrectly classified 34.5% of obese males and 27.3% of obese females. BMI measures were the least sensitive with false-negative rates of 46.4% (males) and 53.1% (females). Males exposed to abdominal/pelvic radiation were at increased risk for misclassification as nonobese by BMI (relative risk, 1.57; 95% confidence interval, 1.25-1.95). The percentages classified as obese were highest with DXA (males, 63.1%; females, 84.8%) and lowest with BMI (males, 35.7%; females, 39.7%). Although skinfolds and WHtR underestimated the percentage classified as obese in comparison with DXA, the differences were not as large.

CONCLUSIONS

Findings suggest that skinfolds and WHtR are better than BMI for obesity classification in CCSs. Clinicians should be aware of the high risk of misclassifying obese CCSs as nonobese.

Bone turnover in long-term survivors of childhood acute lymphoblastic leukemia

BACKGROUND

We investigated the effects of demographic, lifestyle (self-reported smoking status and physical activity levels), cancer-related treatment factors (radiation and chemotherapy), and diet (calcium and vitamin D intake) on bone turnover and the relationship of bone turnover to lumbar spine bone mineral density (BMD) Z-scores (LS-BMD Z-scores) determined by quantitative computed tomography (QCT) in 418 ≥5-year survivors of childhood acute lymphoblastic leukemia (ALL).

PROCEDURE

Bone turnover was assessed by biomarkers including serum bone-specific alkaline phosphatase (BALP), osteocalcin (OC), and urinary N-telopeptide of type I collagen indexed to creatinine (NTX/Cr). The 215 males ranged in age from 9 to 36 years (median age 17 years).

RESULTS

Age and tanner score were inversely associated with all biomarkers (BALP, OC, NTX/Cr) (P < 0.001). Males had higher BALP and OC than females (P < 0.001). Body mass index (BMI) was inversely associated with OC and NTX/Cr (P < 0.001). There was no significant association of biomarkers with lifestyle related factors, ALL treatment-related factors, dietary calcium, vitamin D, or LS-BMD Z-score.

CONCLUSIONS

In this population of long-term survivors of ALL, bone turnover was significantly associated with age, gender, tanner stage, and BMI. ALL-related treatments did not influence bone turnover and bone turnover was not predictive of volumetric LS-BMD Z-score.

Why Healthcare Providers Should Focus on the Fertility of AYA Cancer Survivors: It's Not Too Late!

Reproductive health among cancer survivors is an important quality of life issue. Certain cancer therapies have known fertility risks. There is an existing cohort of adolescents and young adults (AYA) cancer survivors that, seen less frequently in clinical care settings than active patients, are likely not having discussions of fertility and other reproductive health issues. A survivor or healthcare provider can easily assume that the window of opportunity for fertility preservation has passed, however emerging research has shown this may not be the case. Recent data demonstrates a close relationship between fertility and other late effects to conclude that ongoing assessment during survivorship is warranted. Some fertility preservation procedures have also been shown to mitigate common late effects. This review explores the link between late effects from treatment and common comorbidities from infertility, which may exacerbate these late effects. This review also highlights the relevance of fertility discussions in the AYA survivorship population.

Osteoporosis in children and young adults: a late effect after chemotherapy for bone sarcoma

BACKGROUND

Premature bone loss after childhood chemotherapy may be underestimated in patients with bone sarcoma. Methotrexate (MTX), a standard agent in osteosarcoma protocols, reportedly reduces bone mineral density (BMD). The literature, however, has reported cases of BMD reduction in patients with Ewing's sarcoma treated without MTX. Thus, it is unclear whether osteoporosis after chemotherapy relates to MTX or to other factors.

QUESTIONS/PURPOSES

We therefore asked whether (1) young patients with a bone sarcoma had BMD reduction, (2) patients treated with MTX had lower BMD, and (3) other factors (eg, lactose intolerance or vitamin D deficiency) posed additional risks for low BMD.

METHODS

We retrospectively reviewed 43 patients with malignancies who had dual-energy x-ray absorptiometry (DEXA) (lumbar, femoral); 18 with Ewing's sarcoma (mean age, 26 ± 8 years), and 25 with an osteosarcoma (mean age, 27 ± 10 years). The mean time since diagnosis was 8 ± 4 years in the group with Ewing's sarcoma and 7 ± 5 years in the group with osteosarcoma. At last followup we determined BMD (computing z-scores), fracture rate, and lifestyle, and performed serum analysis.

RESULTS

BMD reduction was present in 58% of patients (37% had a z-score between -1 and -2 SD, 21% had a z-score less than -2 SD) in at least one measured site. Seven of the 43 patients (16%) had nontrauma or tumor-associated fractures after chemotherapy. Findings were similar in the Ewing and osteosarcoma subgroups. We found vitamin D deficiency in 38 patients (88%) and borderline elevated bone metabolism; lactose intolerance was present in 16 patients (37%).

CONCLUSION

Doctors should be aware of the possibility of major bone loss after chemotherapy with a risk of pathologic fracture. Vitamin D deficiency, calcium malnutrition, and lactose intolerance may potentiate the negative effects of chemotherapy, and should be considered in long-term patient management.

LEVEL OF EVIDENCE

Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Predictors of bony morbidity in children with acute lymphoblastic leukemia

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Bone mineral density in young adult survivors of acute lymphoblastic leukemia

BACKGROUND

The purpose of the current study was to determine the prevalence of low bone mineral density (BMD) (ie, osteopenia) and identify factors associated with low BMD in young adult survivors of childhood acute lymphoblastic leukemia (ALL).

METHODS

Dual energy x-ray absorptiometry was used to evaluate BMD in 74 randomly selected, long-term childhood ALL survivors initially treated in Minneapolis/St. Paul, Minnesota. Growth hormone (GH)-releasing hormone-arginine stimulation testing was conducted to evaluate peak GH level, and insulin-like growth factor I (IGF-I) and other markers of endocrine functioning were also evaluated in relation to BMD.

RESULTS

The mean age at the time of interview was 30 years, and the mean time since diagnosis was 24 years. Low BMD (Z-score, < or = -1) was present in 24% of subjects, including 1 with osteoporosis. Low BMD was substantially more prevalent in men than in women and was strongly associated with short height. The mean height Z-score for those with low BMD was -1.44, compared with a height Z-score of -0.39 (P < .01) for those with normal BMD. GH insufficiency, low IGF-I Z-score, and current smoking were also suggestive risk factors for low BMD.

CONCLUSIONS

In this long-term follow-up study of childhood ALL survivors, low BMD was found to be more prevalent than expected based on population normative data, specifically in men. The health consequences of early-onset BMD problems in childhood ALL survivors need to be carefully monitored.

Implementing an intervention to improve bone mineral density in survivors of childhood acute lymphoblastic leukemia: BONEII, a prospective placebo-controlled double-blind randomized interventional longitudinal study design

The BONEII study is a large two-phase study. The baseline study (Study 1) aims to estimate the prevalence of diminished bone mineral density (BMD) in patients treated for childhood acute lymphoblastic leukemia (ALL) and identify risk factors for BMD deficits. The interventional phase (Study 2) of BONEII has a placebo-controlled double-blind randomized longitudinal design to evaluate the effects of nutritional counseling and calcium and vitamin D supplementation on changes in BMD and serum and urine markers of bone metabolism. The extensive information being collected through this large study will serve as a repository of relational data about BMD and bone turnover and will support further investigations to assess the association of calcium metabolism, bone turnover, nutritional intake, lifestyle factors (such as exercise and the use of alcohol and tobacco), and the specific agents used in ALL therapy in this rapidly increasing population of childhood cancer survivors.

Some musculo-skeletal sequelae in cancer survivors

This paper deals with some of the musculo-skeletal complication that can occur after cancer treatment. In particular, we focus on Cancer Treatment Induced Bone Loss (CTIBL) and the musculo-skeletal complications that can occur in patients treated for extremity sarcoma. In addition we discuss peripheral neuropathy, musculo-skeletal pain and briefly mention some of the complications related to radiotherapy. CTIBL is mostly studied in breast cancer and prostate cancer survivors. The cause in these groups is mainly due to treatment induced hypogonadism. Other causes of CTIBL are indirect or direct cause of chemotherapy, physical inactivity and inadequate intake of vitamin D and calcium. Treatment of CTIBL consists of diet and lifestyle changes and pharmacological intervention. Extremity bone sarcomas constitute a special group since they often experience mutilating surgery and heavy combination chemotherapy. The treatment results in worse function than the normal population and the amputated usually have lower physical functioning than patients treated with limb sparing surgery (LSS). However, most studies fail to show differences in quality of life between the amputated and LSS. Most of the studies performed on musculo-skeletal sequelae have been done on survivors of childhood cancer, breast cancer or prostate cancer. More studies among the other cancer groups are needed to reveal the extent and prevalence of these complications.

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.

Incidence of skeletal complications during treatment of childhood acute lymphoblastic leukemia: comparison of fracture risk with the General Practice Research Database

BACKGROUND

Skeletal complications during or after treatment of acute lymphoblastic leukemia (ALL) have been frequently reported and can cause substantial morbidity, yet their incidence is not well established. The present study assessed the incidence of fractures, osteonecrosis (ON), and bone pain during ALL treatment and compared the fracture incidence with age- and sex-specific reference data from the UK General Practice Research Database (GPRD).

PROCEDURE

Medical records of 122 ALL patients diagnosed at our institution from 1992 to 2004 were reviewed for information on fractures, ON, bone pain, and their anatomical location, risk group, phase of antileukemic therapy, and time since diagnosis. Evaluation of skeletal complications was followed up until July 2005 or the patient's death. Thirteen children were excluded as they were transferred to other institutions shortly after diagnosis.

RESULTS

Skeletal complications occurred at a 5-year incidence of 32.7%. The 5-year incidence of fractures, ON, and isolated bone pain was 13.5%, 12.1%, and 12.3%, respectively. The relative rate of fractures adjusted for age and sex was 2.03 (95% confidence interval 1.15-3.57) compared to the GPRD, with greatest rates in children <5 years. Thirty ON occurred in 10 patients with a 15 times greater incidence in children >10 years than in those <5 years. Nearly all skeletal complications occurred during maintenance therapy at a median of 14.92 months (range 0.0-53.8) after diagnosis and in weight-bearing bones.

CONCLUSIONS

The doubled fracture rate and the high incidence of skeletal complications during the first years after diagnosis suggest the developing skeleton is very vulnerable in this period. Adolescents develop more ON whereas younger children may be more prone to fractures. Serious "immediate effects" of chemotherapy on bone appear of great concern and should entail preventative studies in this group of patients.

Retention of survivors of acute lymphoblastic leukemia in a longitudinal study of bone mineral density

Attrition in longitudinal studies of survivors of childhood cancer reduces these studies' statistical power, introduces bias and threatens internal and external validity. This study investigated the variables associated with dropout of survivors of acute lymphoblastic leukemia in a trial investigating the effect of vitamin D and calcium supplementation and nutritional counseling on bone mineral density (BMD). Twenty-five participants withdrew from the study. Common reasons given for withdrawing were intolerance of the study drug, family hardship and schedule conflicts. Few statistically and clinically significant differences identified participants who completed the study. Nurses need to be aware of the reasons that participants withdraw from clinical trials, as they are in a strategic position to encourage patients to participate in health promotion studies.

QCT versus DXA in 320 survivors of childhood cancer: association of BMD with fracture history

PURPOSE

To assess agreement on diagnosis of diminished bone mineral density (BMD) and correlation between BMD values obtained by dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) in childhood cancer survivors.

PATIENTS AND METHODS

We retrospectively reviewed lumbar spine QCT and DXA studies for BMD in patients who underwent both imaging studies within a 24-hr period. We determined correlation between BMD values and agreement on diagnosis of diminished BMD obtained by both modalities. Diminished BMD was defined as two or more SDs below mean for age- and gender-matched reference values. We evaluated the relationship of BMD values determined by each modality to self-reported fracture history in the 160 (50%) patients with available reports.

RESULTS

Of 320 patients, 56% (178) were male; 87% (277) were white. Median age was 16.4 (range, 5.1-36.0) years. Median BMD Z-score was -1.43 (range, -5.96 to 3.20) by QCT and -1.30 (range, -5.50 to 2.80) by DXA. Correlation between QCT- and DXA-determined BMD values was significant but low, and agreement on diminished BMD was fair (kappa = 0.32). There was no association between BMD measured by either QCT or DXA and self-reported traumatic fracture history. Male gender was associated with doubling the traumatic fracture risk (P = 0.0499).

CONCLUSIONS

Quantitative computed tomography and DXA may give discrepant results when used to assess bone health in childhood cancer survivors, especially in those of non-white race. This inconsistency in indicators of BMD deficiency may complicate clinical decision-making. Consecutive use of a single modality is recommended to provide reliable longitudinal information.

Osteoporosis in children and adolescents: etiology and management

Bone mass increases progressively during childhood, but mainly during adolescence when approximately 40% of total bone mass is accumulated. Peak bone mass is reached in late adolescence, and is a well recognised risk factor for osteoporosis later in life. Thus, increasing peak bone mass can prevent osteoporosis. The critical interpretation of bone mass measurements is a crucial factor for the diagnosis of osteopenia/osteoporosis in children and adolescents. To date, there are insufficient data to formally define osteopenia/osteoporosis in this patient group, and the guidelines used for adult patients are not applicable. In males and females aged <20 years the terminology 'low bone density for chronologic age' may be used if the Z-score is less than -2. For children and adolescents, this terminology is more appropriate than osteopenia/osteoporosis. Moreover, the T-score should not be used in children and adolescents. Many disorders, by various mechanisms, may affect the acquisition of bone mass during childhood and adolescence. Indeed, the number of disorders that have been identified as affecting bone mass in this age group is increasing as a consequence of the wide use of bone mass measurements. The increased survival of children and adolescents with chronic diseases or malignancies, as well as the use of some treatment regimens has resulted in an increase in the incidence of reduced bone mass in this age group. Experience in treating the various disorders associated with osteoporosis in childhood is limited at present. The first approach to osteoporosis management in children and adolescents should be aimed at treating the underlying disease. The use of bisphosphonates in children and adolescents with osteoporosis is increasing and their positive effect in improving bone mineral density is encouraging. Osteoporosis prevention is a key factor and it should begin in childhood. Pediatricians should have a fundamental role in the prevention of osteoporosis, suggesting strategies to achieve an optimal peak bone mass.

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

To investigate the hypothesis that survivors of pediatric solid cancer have low bone mineral density, a cross-sectional study was done of subjects who had received treatment for pediatric solid tumors before 16 years of age and were less than 40 years old at follow-up. Excluded were subjects treated for acute lymphoblastic leukemia or those who had received cranial irradiation, total body radiation, or nonautologous bone marrow transplant. The study group consisted of 38 subjects, with the most common diagnoses being lymphoma (n = 17), sarcoma (n = 8), Wilms tumor (n = 5), and neuroblastoma (n = 4). Median age was 22 years (range 12-32). Time from diagnosis of underlying cancer averaged 12.6 years (range 5.5-20.3). Using criteria of osteopenia (Z-score < or = -1.0 and > -2.0) and osteoporosis (Z-score < or = -2.0) for any one or more areas including total body, lumbar spine, total hip, or femoral neck density, 13 of the 38 subjects (34%) had osteopenia or osteoporosis. A further six subjects (16%) had isolated upper extremity osteopenia or osteoporosis. Multivariate analysis showed a direct relationship between the number of chemotherapy drugs administered and the presence of osteopenia or osteoporosis in the lower extremities (P = 0.03). Young survivors of childhood solid tumors are at increased risk of developing premature osteopenia or osteoporosis, and screening evaluations and follow-up are warranted.

Bone health across the generations: a primer for health providers concerned with osteoporosis prevention

Osteoporosis represents a major public health problem by virtue of later life association with fragility fractures which may indeed be the first sign of this "silent epidemic". While as prevalent as cardiovascular and other age-related chronic diseases, efforts at osteoporosis prevention have been less successful due to limited commitment among the public to take steps to maintain their "bone health", and fragmentation of osteoporosis management among different health specialties, indeed with many reports of deficient physician knowledge of the subject. This paper presents a survey of the factors that contribute to bone loss or accrual in women across the generations, including adolescence, the reproductive years, the menopause inception, and the decades thereafter. Health providers in a variety of disciplines aware of and inquiring about the spectrum of bone changes in their patients over the generations may intervene effectively in a more timely manner to limit future fracture occurrence.

Bone mineral density and osteonecrosis in survivors of childhood allogeneic bone marrow transplantation

Our purpose was to evaluate frequency and severity of bone mineral decrements and frequency of osteonecrosis in survivors of pediatric allogeneic bone marrow transplantation (alloBMT). We retrospectively reviewed demographic information, treatment, magnetic resonance (MR) imaging studies (hips and knees), and bone mineral density (BMD) studies of 48 patients as measured by quantitative computed tomography (QCT). In all, 24 patients were male; 37 were Caucasian. Median age at alloBMT was 10.3 years (1.6-20.4 years). Of the 48 patients, 43 underwent QCT. Median time between alloBMT and imaging was 5.1 years (1.0-10.2 years). Median BMD Z-score was -0.89 (-4.06 to 3.05). BMD Z-score tended to be associated with female sex (P=0.0559) but not with age at BMT, race, primary diagnosis, time from alloBMT, T-cell depletion of graft, total-body irradiation, or acute/chronic graft-versus-host disease (GVHD). MR showed osteonecrosis in 19 of 43 (44%). We found no associations between osteonecrosis and sex, race, diagnosis, age at BMT, history of GVHD, time from BMT, or T-cell depletion. Seven patients (15%) had MR changes of osteonecrosis and BMD Z-scores of less than -1 s.d. We conclude that pediatric alloBMT survivors have decreased BMD and are at risk of osteonecrosis. They should be monitored to assure early intervention that may ameliorate adverse outcomes.

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.

Reproductive medicine in a late effects of cancer clinic

This review discusses the most commonly observed problems in young people who have survived childhood cancer, with particular emphasis on the issues of fertility. It also describes the role of the late effects clinic in transitional care and the multidisciplinarity of the clinicians required to meet the needs of these young people. There is a need for evidence-based guidelines for management of long-term survivors.

The effect of chemotherapy on the morphology of the growth plate and metaphysis of the growing skeleton

AIM

To establish the effect of three single chemotherapeutic agents on the growing skeleton, male Wistar rats were studied.

METHODS

From the age of 4 weeks the rats were given iv doxorubicin (DOX) 15 mg/m(2) body surface area (BSA), methotrexate (MTX) 60 mg/m(2) BSA or cisplatin (CDDP) 7.5 mg/m(2) BSA. One non-treated control group was fed ad libitum (ad lib) and for every drug-treated group there was a diet-control group. After dissection at 13 weeks of age, morphology of the proximal tibial growth plate and metaphysis were studied.

RESULTS

Compared to the ad lib group, DOX significantly decreased and MTX increased growth plate height (P<0.05). CDDP decreased height of the proliferating layer (P<0.05). Trabecular volume was decreased in the DOX and CDDP treated rats compared to the ad lib group (P=0.054). Compared to the diet control group trabecular bone volume was unaffected in the DOX group and decreased in the MTX and CDDP group (P<0.05).

CONCLUSIONS

Doxorubicin causes growth plate thinning, methotrexate increases growth plate height and cisplatin does not affect growth plate height. All three chemotherapeutic agents decrease the trabecular volume of the proximal tibial metaphysis. Part of the effect of DOX, MTX and CDDP is related to the treatment induced malnutrition.

In vitro effects of combination chemotherapy on osteoblasts: implications for osteopenia in childhood malignancy

Clinical studies suggest that combination chemotherapy adversely affects bone metabolism and in vitro studies have demonstrated that a reduction in osteoblast numbers results in diminished bone formation. The aim of this study was to investigate the in vitro effects of combinations of chemotherapeutic agents on primary human osteoblast-like (hOB) cell numbers and apoptosis, and to assess the ability of hOBs and osteoprogenitor (HCC1) cells to recover from prior treatment with chemotherapy. As glucocorticoids are frequently administered during treatment with cytotoxic agents, we evaluated whether glucocorticoids influence the chemosensitivity of hOB and human osteosarcoma (MG63) cells. Culture with clinically relevant concentrations of the individual chemotherapeutic agents reduced hOB cell numbers compared with control (p < 0.01) and also increased the numbers of apoptotic cells (p < 0.05). Potentiation of cytotoxicity was observed when agents were given in combination, thus further reducing cell numbers, and this effect was greatest when vincristine was given in combination with asparaginase. Following culture with a chemotherapeutic agent, there was greater recovery of hOB compared with HCC1 cell numbers (p < 0.01). Pretreatment with glucocorticoids ameliorated the adverse effects of chemotherapeutic agents on hOB and MG63 cell numbers and apoptosis (p < 0.05). We conclude that the use of combination chemotherapy contributes to osteopenia in childhood malignancy by a reduction in osteoblast numbers. However, this effect may be attenuated by the concomitant use of glucocorticoids.

Genetics of osteoporosis

Osteoporosis is a common multifactorial disorder of reduced bone mass. The disorder in its most common form is generalized, affecting the elderly, both sexes, and all racial groups. Multiple environmental factors are involved in the pathogenesis. Genes also play a major role as reflected by heritability of many components of bone strength. Quantitative phenotypes in bone strength in the normal population do not conform to a monogenetic mode of inheritance. The common form of osteoporosis is generally considered to be a polygenic disorder arising from the interaction of common polymorphic alleles at quantitative trait loci, with multiple environmental factors. Finding the susceptibility genes underlying osteoporosis requires identifying specific alleles that coinherit with key heritable phenotypes in bone strength. Because of the close correspondence among mammalian genomes, identification of the genes underlying bone strength in mammals such as the mouse is likely to be of major assistance in human studies. Identification of susceptibility genes for osteoporosis is one of several important approaches toward the long-term goal of understanding the molecular biology of the normal variation in bone strength and how it may be modified to prevent osteoporosis. As with all genetic studies in humans, these scientific advances will need to be made in an environment of legal and ethical safeguards that are acceptable to the general public.

Osteoporosis in children and adolescents: diagnosis, risk factors, and prevention

Bone mass acquired during childhood and adolescence is a key determinant of adult bone health. Peak bone mass, which is achieved in late adolescence, is a main determinant of osteoporosis in adulthood. Therefore, any factor adversely impacting on bone acquisition during childhood or adolescence can potentially have long-standing detrimental effects on bone health predisposing to osteoporosis and fracture risk. Thus, osteoporosis can well have its origin in childhood and adolescence. Pediatricians should be playing an active role in osteoporosis diagnosis and prevention. It is increasingly recognized that osteoporosis may occur in some disorders of children and adolescents. In this paper we review the diagnostic criteria of osteopenia/osteoporosis by densitometric assessment of bone mineral density, the contributing factors, and the mechanisms whereby several disorders may affect the acquisition of bone mass in children and adolescents. Finally, some recommendations to optimize peak bone mass in order to prevent osteopenia/osteoporosis are suggested.

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.