Modeling pathways for low bone mass in children with malignancies

Clinical Considerations in Returning Pediatric and Young Adults With Cancer to Physical Activity

ABSTRACT

There is a gap in the literature on the best treatment of clinical sequelae within adolescent and young adult pediatric cancer populations. Children, adolescents, and young adults are at risk for a multitude of immediate and late effects of their disease and treatment that warrant a comprehensive, multidisciplinary team approach to optimize care. Sports medicine providers are well-equipped with their background to join the oncology rehabilitation team in diagnosing and managing cancer-related impairments to help these populations live a healthier and more active lifestyle. In this manuscript, four essential clinical components to consider when returning children, adolescents, and young adults with cancer history to physical activity are discussed: chemotherapy-induced peripheral neuropathy, cardiotoxicity, nutritional deficiencies, and deconditioning.

Low bone mineral density is associated with hypogonadism and cranial irradiation in male childhood cancer survivors

We investigated if bone mineral density was related to testosterone deficiency and/or previous cancer treatment in men who were childhood cancer survivors. Men with untreated testosterone deficiency or previous treatment with cranial irradiation were at increased risk of impaired bone health. Prevention of osteoporosis should be considered in their follow-up.

INTRODUCTION

Childhood cancer survivors (CCS) are at increased risk of hypogonadism. Reduced bone mineral density (BMD) has been reported in CCS but it is unclear whether this is due to hypogonadism or a direct effect of cancer therapy. This study investigated BMD in CCS, and association with hypogonadism, previous treatment and cancer type.

METHODS

Investigation of 125 CCS (median age 33.7 at inclusion; 9.6 at diagnosis) and 125 age-matched population controls. Serum testosterone and luteinizing hormone were assayed and BMD at total hip and lumbar spine L1-L4 measured. The mean difference in BMD (g/cm2; 95% CI) between CCS and controls was analysed. Odds ratios (OR; 95% CI) for low BMD were also calculated.

RESULTS

Overall, BMD in the CCS cohort did not significantly differ from controls. However, compared with eugonadal CCS, the CCS with untreated hypogonadism had lower BMD at the hip (mean difference - 0.139 (- 0.210; - 0.067); p < 0.001) and spine (- 0.102 (- 0.174; - 0.030); p = 0.006). They also had a higher risk of low hip BMD (OR 4.1 (1.3; 14); p = 0.018). CCS treated with cranial irradiation also had lower BMD (hip - 0.076 (- 0.133; - 0.019); p = 0.009; spine - 0.071 (- 0.124; - 0.018); p = 0.009) compared with controls. The latter associations remained statistically significant after adjustment for hypogonadism.

CONCLUSIONS

CCS with hypogonadism or previously treated with cranial irradiation are at increased risk of impaired bone health. Prevention of osteoporosis should be considered as an important part in future follow-up of these men.

No impact of disease and its treatment on bone mineral density in survivors of childhood acute lymphoblastic leukemia

BACKGROUND

Acute lymphoblastic leukemia (ALL) and its treatment are often implicated in adversely affecting bone health. Conflicting reports in the literature and a paucity of studies from the developing world prompted us to study bone mineral density (BMD) in childhood ALL survivors.

METHODS

BMD lumbar spine (LS) and whole body (WB) were evaluated, using dual energy x-ray absorptiometry in 65 pediatric ALL survivors who had been off-therapy for at least 2 years. The control group constituted of 50 age- and sex-matched healthy siblings. Kernel density plots were used to compare BMD among cases and controls. The disease-, treatment-, hormone- and lifestyle-related factors likely to modulate BMD were analyzed using the Mann-Whitney U test and Student's t-test.

RESULTS

At a median of 4.3 years (range, 2-14.8 years) since cessation of therapy, height-adjusted (HA) mean BMD Z-scores of LS (-0.67 ± 1.11, -0.607 ± 1.05, P = 0.759) and WB (-0.842 ± 0.92, -0.513 ± 0.97, P = 0.627) were comparable among the cases and controls. Disease, treatment (chemotherapy, cranial radiotherapy) and endocrine factors did not predict low BMD. However, survivors with calcium intake <800 mg/day (WB, P = 0.018) and hypovitaminosis D (≤25 nmol/L) had lower BMD values (HA-WB, P = 0.046) than the controls. A significant proportion of survivors were overweight or obese and had higher BMD Z-scores (HA-LS, P = 0.003; HA-WB, P = 0.028).

CONCLUSION

BMD Z-scores were similar among ALL survivors and controls. It was reassuring that there was no detrimental impact of the disease or its treatment on BMD. Future studies are required to determine the best possible ways to target the modifiable risk factors (diet, vitamin D) to optimize bone health.

AVALIAÇÃO DOS EFEITOS ÓSSEOS TARDIOS E COMPOSIÇÃO CORPORAL DE CRIANÇAS E ADOLESCENTES TRATADOS DE LEUCEMIA LINFOIDE AGUDA SEGUNDO PROTOCOLOS BRASILEIROS

Objective:

To evaluate the impact of therapy on bone mineral density (BMD) and body composition in survivors of acute lymphoblastic leukemia (ALL) treated in accordance with Brazilian protocols by the Brazilian Cooperative Group of Treatment of Lymphoblastic Leukemia in Childhood (GBTLI) LLA-93 and LLA-99.

Methods:

A cross-sectional study with 101 patients was performed. BMD and body composition were evaluated using bone densitometry and were interpreted according to the age group and the reference population. Values between -1.1 and -1.9 in the group of children under 20 years were considered as risk group for low BMD z-scores. BMD values were compared to clinical characteristics, treatment received and body composition. A chi-square test, Fisher’s exact test, likelihood ratio and Student’s t-test were applied, with a 5% significance level.

Results:

The patients presented a frequency of fractures of 2%, of osteonecrosis, 2%, and of low BMD, 2.9%. In the group of 79 patients under 20 years of age, three had low BMD. The 16 that presented risk for low BMD, demonstrated lower valutes in lumbar vertebrae L1-L4 (p=0.01) and whole body (p=0.005), and smaller values of lean body mass (p=0.03). In the group of 22 patients over 20 years of age, ten had osteopenia.

Conclusions:

The low impact of treatment on BMD of this study confirms the concept that the bone mass gain occurs with increasing age and that the treatment does not influence the process. The population at risk for low BMD values presented lower bone mass values and could benefit from a long-term monitoring for possible bone toxicity.

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.

Calcium and cholecalciferol supplementation provides no added benefit to nutritional counseling to improve bone mineral density in survivors of childhood acute lymphoblastic leukemia (ALL)

BACKGROUND

We sought to improve lumbar spine bone mineral density (LS-BMD) in long-term survivors of childhood acute lymphoblastic leukemia (ALL) using calcium and cholecalciferol supplementation.

PROCEDURE

This double-blind, placebo-controlled trial randomized 275 participants (median age, 17 [9-36.1] years) with age- and gender-specific LS-BMD Z-scores <0 to receive nutritional counseling with supplementation of 1,000 mg/day calcium and 800 International Unit cholecalciferol or placebo for 2 years. The primary outcome was change in LS-BMD assessed by quantitative computerized tomography (QCT) at 24 months. Linear regression models were employed to identify the baseline risk factors for low LS-BMD and to compare LS-BMD outcomes.

RESULTS

Pre-randomization LS-BMD below the mean was associated with male gender (P = 0.0024), White race (P = 0.0003), lower body mass index (P < 0.0001), and cumulative glucocorticoid doses of ≥ 5,000 mg (P = 0.0012). One hundred eighty-eight (68%) participants completed the study; 77% adhered to the intervention. Mean LS-BMD change did not differ between survivors randomized to supplements (0.33 ± 0.57) or placebo (0.28 ± 0.56). Participants aged 9-13 years and those 22-35 years had the greatest mean increases in LS-BMD (0.50 ± 0.66 and 0.37 ± 0.23, respectively). Vitamin D insufficiency (serum 25[OH]D <30 ng/ml) found in 296 (75%), was not associated with LS-BMD outcomes (P = 0.78).

CONCLUSION

Cholecalciferol and calcium supplementation provides no added benefit to nutritional counseling for improving LS-BMD among adolescent and young adult survivors of ALL (93% of whom had LS-BMD Z-scores above the mean at study entry).

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.