Bone density in survivors of childhood cancer

Quantitative Ultrasound of Proximal Phalanxes in Childhood Acute Lymphoblastic Leukemia Survivors

Reduced bone mineral density (BMD) is a well-known complication in childhood acute lymphoblastic leukemia (ALL) survivors; the optimal method to assess BMD is still debated. We studied BMD by quantitative ultrasound (QUS) in 72 ALL survivors, and evaluated any correlation with cumulative doses of steroids and cytotoxic agents. Mean age at diagnosis was 61±45 months, while mean age at QUS was 318.3±129.6 months; mean period of follow-up was 41.2±37.8 months. Mean amplitude-dependent speed of sound z-score was -1.22±1.19. Ten survivors (13.8%) presented a z-score below -2 SD. A negative correlation was found between amplitude-dependent speed of sound z-score and age at diagnosis (P=0.01). A positive correlation was observed with length of follow-up (P=0.01). No correlation was found with cytotoxic drugs. This study represents the largest cohort of childhood ALL survivors studied by QUS. Our results suggest that QUS for its characteristics of being radiation free may be an effective option to assess BMD in pediatric age. In addition, our data outline the importance to improve the awareness about the specific expression of this complication in the pediatric age, concerning the major determinants of bone impairment, which are the disease itself and the phase of bone growth when the disease occurs.

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.

Bone mineral density, thyroid function, and gonadal status in young adult survivors of childhood cancer

Introduction

During the last years, changes in the diagnosis and treatment have caused a significant increase of the number of young adults who experienced cancer in childhood. This enlarging population is affected by many health problems, including multiple hormone deficiencies and bone mineral deficits. This is the first polish study assessing bone mineral density and endocrine status in young adult cancer survivors.

Material and methods

A total of 76 long-term survivors treated for pediatric cancer were identified. The mean age at the time of study was 24.1 ±3.5 years. Bone mineral density and TSH, fT3, fT4, FSH, LH, estradiol and testosterone level were assessed for each patient.

Results

Nine subjects were diagnosed with subclinical hypothyroidism. We found higher level of TSH in the study group, in comparison with control group (p = 0.015). Eighteen patients had increased level of FSH. In the study group higher number of patients with high FSH level was found in comparison with the control group (p = 0.049). A low BMD was observed in 7 patients whereas mild BMD deficits were found in 19 participants.

Conclusions

In conclusion, our data show that young adult cancer survivors might experienced various hormonal problems including low bone mass, thyroid impairment and gonadal dysfunction. Some of the patients required treatment, but they were not diagnosed before this study. There is the lack of proper clinical assessment among adult childhood cancer survivors in Poland. Therefore, we demonstrated the need for a comprehensive plan for longitudinal follow-up for late effects in these population.

Bone metastases, skeletal-related events, and survival among children with cancer in Denmark

Bone metastases and skeletal-related events (SREs), including radiation therapy or surgery to bone, pathologic fracture, or spinal cord compression, among children have not been described in a population-based study. We examined the rate of bone metastasis, SREs, and survival in the Danish pediatric cancer population. We identified children below 18 years with a first-time diagnosis of cancer between January 1, 1994 and December 31, 2009 in the Danish Cancer Registry. From the Danish National Registry of Patients, we obtained bone metastasis and SRE diagnoses, and estimated incidence rates (IRs). We estimated 6-month, 1-year, and 5-year survival using Kaplan-Meier curves. Of 2652 children, 35 (1.3%) developed bone metastasis during a mean follow-up of 7.0 years (IR=1.9 per 1000 person-years [95% confidence interval (CI), 1.4-2.6]). IRs were substantially higher among children with solid tumors than those with hematologic malignancies (IR=3.2 [95% CI, 2.3-4.6] and IR=0.48 [95% CI, 0.18-1.3]). Survival was poorer for children with bone metastasis than those without bone metastasis. Among children with bone metastasis, 67% experienced an SRE during a mean follow-up of 1.1 years, yielding an IR of 590 per 1000 person-years (95% CI, 381-915). Bone metastases are rare among children with cancer, but SREs are a common consequence.

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.

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.

Modeling pathways for low bone mass in children with malignancies

Children with malignancies have low bone mass. Pathways for metabolic bone disease were investigated in children with cancer by concomitantly assessing lifestyle, clinical, and biochemical predictors of bone mass. Forty-one children who were receiving cancer therapy for 61 weeks and 39 controls were studied. Data on lifestyle factors, biochemical and hormonal parameters, dual-energy X-ray absorptiometry bone mass measurements, body composition, and bone age were obtained. Compared with controls, patients had higher weight percentile and fat mass, a 6-month delay in bone age, and lower estradiol levels. They also had higher parathyroid hormone levels and lower bone remodeling markers and bone mass. Age, height, lean mass, fat mass, and bone maturation correlated positively with several bone mass variables, so did serum estradiol, testosterone, and markers of bone remodeling. Conversely, corticosteroids, methotrexate (MTX), and intrathecal therapy negatively correlated with bone mass at the spine and hip (R = -0.33 to 0.40, p < 0.04). In the adjusted analyses, bone maturation, serum osteocalcin level, MTX, and intrathecal therapy were significant predictors of lumbar spine and total body Z-scores, bone maturation accounting for the largest proportion in Z-score variance. Chemotherapy-induced delay in bone maturation and suppression of bone modeling are major pathophysiologic pathways predicting bone mass in children with 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 status in children with congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is caused by a deficiency in an adrenal enzyme resulting in alterations in cortisol and aldosterone production. Bone status is affected by chronic glucocorticoid therapy and excess androgen exposure in children with CAH. This cross-sectional study enrolled participants with 21-hydroxylase deficiency from a pediatric referral center. Bone mineral density in the participants was normal when compared to age, gender and ethnicity adjusted standards, with respect to chronological age or bone age. Lean body mass was positively correlated with bone mineral content (BMC), independent of fat mass (p < 0.001). There was no significant correlation between glucocorticoid dose or serum androgen levels and skeletal endpoints. In conclusion, lean body mass appears to be an important correlate of BMC in patients with CAH. The normal bone status may be explained by the differential effects of glucocorticoids on growing bone, beneficial androgen effects, or other disease specific factors.

Bone mineral density in survivors of childhood brain tumours

BACKGROUND

Osteopenia has been reported in children surviving acute lymphoblastic leukaemia, apparently as consequence of therapy. Few studies have been published on bone mineral density (BMD) evaluation in children surviving from brain tumours. The endocrine system in these patients is frequently affected as consequence of therapeutic interventions such as cranial irradiation and anti-neoplastic agents: growth hormone deficiency is the most common adverse sequel. The pathogenesis of osteopenia in brain cancer survivors is multi-factorial but still uncertain.

OBJECTIVE

The aim of this study is to examine bone mass in 12 brain cancer survivors and its relationship with their hormonal status.

RESULTS AND DISCUSSION

We observed that most of the patients had a BMD that was lower than normal in both the lumbar column and in the femoral neck. Bone mass loss was higher in the lumbar region rather than in the femoral neck, due to spinal radiation therapy and to the effect of hormonal deficiencies. Particularly hypogonadism, but also multiple hormonal deficiencies, are associated with lower BMD values. Experience in clinical care of these patients suggests the importance of periodic evaluations of BMD, especially in those with secondary hormone deficiencies. Moreover, the periodic assessment of the hypothalamus-pituitary function is essential for an early diagnosis of hormonal insufficiency, primarily hypogonadism, to precociously detect bone mineral loss and to prevent pathological fractures, thus improving the quality of life.