GH deficiency caused by cranial irradiation during childhood: factors and markers in young adults

Policy for transitioning childhood-onset growth hormone deficiency from pediatric to adult endocrine care in Belgium

Growth hormone (GH) deficiency (GHD) in children and adolescents can vary in severity and origin, with GH replacement therapy proving effective in achieving genetic target height. Optimal outcomes are seen in those treated early and with higher doses. As patients approach adult height, priorities shift towards optimizing metabolic effects, maintaining body composition, and enhancing bone mass and muscle strength. Transitioning from pediatric to adult care presents challenges, including accurately identifying candidates for continued GH therapy, reevaluating persistent GHD, and preventing treatment discontinuation. Assessing readiness for transition and self-management skills is crucial. This Policy and Practice Review provides a comprehensive overview of current policies, regulations, and guidelines pertinent to managing GHD transition in Belgium. We integrate perspectives from national academic and nonacademic clinical stakeholders in pediatric and adult endocrine care to provide an updated policy framework. This framework underscores the importance of sustained GH therapy during transition, particularly for individuals with persistent GHD, with the goal of optimizing practices and improving outcomes during this critical period.

Insights from an advisory board: Facilitating transition of care into adulthood in brain cancer survivors with acquired pediatric growth hormone deficiency

OBJECTIVE

Children with growth hormone deficiency (GHD) face multiple challenges that can negatively impact the transition from pediatric to adult endocrinology care. For children with GHD resulting from brain cancer or its treatment, the involvement of oncology care providers and possible disease-related comorbidities add further complexity to this transition.

DESIGN

An advisory board of pediatric and adult endocrinologists was convened to help better understand the unique challenges faced by childhood cancer survivors with GHD, and discuss recommendations to optimize continuity of care as these patients proceed to adulthood. Topics included the benefits and risks of growth hormone (GH) therapy in cancer survivors, the importance of initiating GH replacement therapy early in the patient's journey and continuing into adulthood, and the obstacles that can limit an effective transition to adult care for these patients.

RESULTS/CONCLUSIONS

Some identified obstacles included the need to prioritize cancer treatment over treatment for GHD, a lack of patient and oncologist knowledge about the full range of benefits provided by long-term GH administration, concerns about tumor recurrence risk in cancer survivors receiving GH treatment, and suboptimal communication and coordination (e.g., referrals) between care providers, all of which could potentially result in treatment gaps or even complete loss of follow-up during the care transition. Advisors provided recommendations for increasing education for patients and care providers and improving coordination between treatment team members, both of which are intended to help improve continuity of care to maximize the health benefits of GH administration during the critical period when childhood cancer survivors transition into adulthood.

Metabolic/endocrine disorders in survivors of childhood-onset and cranial radiotherapy- treated ALL/NHL: a meta-analysis

BACKGROUND

Cranial radiotherapy (CRT) is recommended to high-risk pediatric patients with acute lymphoblastic leukemia or aggressive non-Hodgkin's lymphoma (ALL/NHL). However, effects of CRT treatment on the development of metabolic/endocrine disorders remain unclear. This meta-analysis aimed to identify metabolic and endocrine disturbances in survivors of childhood-onset and CRT-treated ALL/NHL.

METHODS

Different online databases were searched using restricted search fields. Follow-up data and outcome measurements, including the prevalence of growth hormone (GH) deficiency, hypothyroidism, vitamin D deficiency, overweight/obesity, and hypogonadism were recorded. The height data was indicated by height-standard deviation score (height-SDS). Statistical estimates such as odds ratio (OR) and weighted standard mean difference (SMD) were compared between additional CRT treatment group and non-CRT treatment group. Study-to-study heterogeneity was calculated by calculating I-squared statistic, and fixed/random effect was applied to synthesize and analyze extracted data.

RESULTS

Fifteen studies were included (4269 patients in total). Adult height SDS was lower in CRT-treated patients (pooled SMD = -0.581, 95% CI: -0.649--0.512), and CRT-treated patients were likely to develop short stature (pooled OR = 2.289, 95% CI:1.674-3.130). Regardless of the study year, which potentially reflects the state-of-the-art CRT technique, the prevalence of short stature and GH deficiency was time-independent. Additionally, previous CRT can increase the risk of precocious puberty (pooled OR = 2.937, 95% CI: 1.281-6.736), hypothyroidism (pooled OR = 2.057, 95% CI:1.510-2.801), and hypogonadism (pooled OR = 3.098, 95% CI:2.521-3.807). However, the risk of being overweight/obese was similar between the patients with and without CRT (pooled OR = 1.278, 95% CI: 0.675-2.421).

CONCLUSION

Childhood-onset and CRT-treated ALL/NHL survivors are likely to have shorter height, precocious puberty, hypothyroidism, and hypogonadism.

Pre- and postdiagnosis growth failure, adult short stature, and untreated growth hormone deficiency in radiotherapy-treated long-term survivors of childhood brain tumor

PURPOSE

Growth failure is common in radiotherapy-treated long-term survivors of pediatric brain tumors, but studies on longitudinal growth in this patient group are lacking. Here, the aim was to assess the changes in growth patterns before and after brain tumor diagnosis, the adult height, and the risk factors for compromised growth. The incidence and treatment practices of growth hormone deficiency were analyzed.

METHODS

A cohort of 73 survivors of childhood brain tumor (median age 27.2 years, range 16.2 to 43.8 years) was studied after a median follow-up period of 20.4 years from diagnosis (IQR 14.9 to 22.9 years). Patients were treated in five university hospitals in Finland between 1970 and 2008. Growth curves, final height, and patient- and disease-related risk factors for compromised growth during different growth periods were analyzed. Laboratory analyses for IGF-1 and IGFBP-3 were performed at the follow-up.

RESULTS

Growth failure was evident at diagnosis, with a mean height decline of -0.6 SDS (standard deviation score) from birth (95% CI -1.15 to -0.05). Mean height SDS decline after the diagnosis was -1.09 SDS (95%CI -1.51 to -0.66). At follow-up, 37% of the study subjects (27/73) had true short stature (height < -2 SDS). The mean height deficit corrected for target height was -1.9 SDS (95% CI -1.45 to -2.40). Growth failure was associated with the age at diagnosis, corticosteroid dose, radiotherapy modality and mean dose of irradiation in the thalamic area. Low IGF-1 level (below -2.0 SDS) was found in 32% (23/72), and untreated growth hormone deficiency in 40% (29/72) of the subjects.

CONCLUSION

Longitudinal growth impairment was common in radiotherapy-treated survivors of childhood brain tumor, resulting in compromised adult height. Loss of growth potential was evident already at diagnosis and further accelerated by the treatments. At young adulthood, unrecognized growth hormone deficiency was common.

Safety of growth hormone replacement in survivors of cancer and intracranial and pituitary tumours: a consensus statement

Growth hormone (GH) has been used for over 35 years, and its safety and efficacy has been studied extensively. Experimental studies showing the permissive role of GH/insulin-like growth factor 1 (IGF-I) in carcinogenesis have raised concerns regarding the safety of GH replacement in children and adults who have received treatment for cancer and those with intracranial and pituitary tumours. A consensus statement was produced to guide decision-making on GH replacement in children and adult survivors of cancer, in those treated for intracranial and pituitary tumours and in patients with increased cancer risk. With the support of the European Society of Endocrinology, the Growth Hormone Research Society convened a Workshop, where 55 international key opinion leaders representing 10 professional societies were invited to participate. This consensus statement utilized: (1) a critical review paper produced before the Workshop, (2) five plenary talks, (3) evidence-based comments from four breakout groups, and (4) discussions during report-back sessions. Current evidence reviewed from the proceedings from the Workshop does not support an association between GH replacement and primary tumour or cancer recurrence. The effect of GH replacement on secondary neoplasia risk is minor compared to host- and tumour treatment-related factors. There is no evidence for an association between GH replacement and increased mortality from cancer amongst GH-deficient childhood cancer survivors. Patients with pituitary tumour or craniopharyngioma remnants receiving GH replacement do not need to be treated or monitored differently than those not receiving GH. GH replacement might be considered in GH-deficient adult cancer survivors in remission after careful individual risk/benefit analysis. In children with cancer predisposition syndromes, GH treatment is generally contraindicated but may be considered cautiously in select patients.

TransCon human growth hormone for children with growth hormone deficiency: a technology evaluation

INTRODUCTION

Standard-of-care treatment for growth hormone deficiency consists of daily subcutaneous injections of recombinant human growth hormone, also known as somatropin. Although somatropin treatment is well established, the burden of daily injections can lead to poor adherence and quality of life. In this regard, a TransCon human growth hormone (lonapegsomatropin-tcgd) technology was developed to optimize the therapeutic effect of daily somatropin for the treatment of children with growth hormone deficiency.

AREAS COVERED

The authors reviewed the effects of lonapegsomatropin-tcgd in children with growth hormone deficiency.

EXPERT OPINION

Lonapegsomatropin-tcgd was found to be non-inferior to and superior to daily somatropin for annualized height velocity. In addition, the safety was comparable between them. As a result, the convenient dosing of lonapegsomatropin-tcgd has the potential to improve patient adherence, leading to increased efficacy and quality of life. Medication adherence, quality of life, long-term safety, and cost-effectiveness studies comparing lonapegsomatropin-tcgd and daily somatropin are required to confirm these possible benefits.

GH deficiency in cancer survivors in the transition age: diagnosis and therapy

BACKGROUND

Survival rates among childhood cancer survivors (CCSs) have significantly risen in the last 40 years due to substantial improvements in treatment protocols. However, this improvement has brought with it serious late effects that frequently involve the endocrine system. Of the endocrine disorders, GH deficiency (GHD) is the most common among CCSs as a consequence of a history of cancers, surgery, and/or radiotherapy involving the hypothalamo-pituitary region.

METHODS

A comprehensive search of English language articles regardless of age was conducted in the MEDLINE database between December 2018 and October 2019. We selected all studies on GH therapy in CCSs during the transition age regarding the most challenging topics: when to retest; which diagnostic tests and cut-offs to use; when to start GH replacement therapy (GHRT); what GH dose to use; safety; quality of life, compliance and adherence to GHRT; interactions between GH and other hormonal replacement treatments.

RESULTS

In the present review, we provide an overview of the current clinical management of challenges in GHD in cancer survivors in the transition age.

CONCLUSIONS

Endocrine dysfunction among CCSs has a high prevalence in the transition age and increase with time. Many endocrine disorders, including GHD, are often not diagnosed or under-diagnosed, probably due to the lack of specialized centers for the long-term follow-up. Therefore, it is crucial that transition specialized clinics should be increased in terms of number and specific skills in order to manage endocrine disorders in adolescence, a delicate and complex period of life. A multidisciplinary approach, also including psychological counseling, is essential in the follow-up and management of these patients in order to minimize their disabilities and maximize their quality of life.

The Predictive Value of Insulin-Like Growth Factor 1 in Irradiation-Dependent Growth Hormone Deficiency in Childhood Cancer Survivors

BACKGROUND

The literature contains conflicting reports on the value of low insulin-like growth factor 1 (IGF-1) levels in predicting radiation-induced growth hormone (GH) deficiency (GHD) in childhood cancer survivors (CCS). These reports often involve small samples of patients who have received irradiation or mixed cohorts including non-irradiated subjects.

OBJECTIVE

We undertook an analysis of the predictive value of low IGF-1 in CCS at risk for GHD after cranial radiotherapy involving the hypothalamic-pituitary (HP) area in a large single-centre cohort.

METHODS

We performed a retrospective analysis on 158 CCS diagnosed with GHD between January 1, 2003 and October 31, 2017 and identified 117 patients who received radiation for tumours not direct ly involving the HP area.

RESULTS

In this cohort, IGF-1 levels <-2 standard deviation scores (SDS) had a sensitivity of 31.9% for GHD; however, they were statistically more frequent (p = 0.0023) and had a higher sensitivity (45.6%) among patients with severe GHD. At final height reassessment, IGF-1 <-2 SDS had a sensitivity of 35.0% for GHD, but a positive predictive value of 100%. Finally, pretreatment IGF-1 values showed no correlation with the number of impaired pituitary hormonal axes in patients with multiple pituitary deficiencies.

CONCLUSIONS

IGF-1 levels <-2 SDS showed a low sensitivity at predicting radiation-induced GHD both in childhood and in adulthood, but a high positive predictive value for GH status at final height reassessment.

Pituitary disease in pediatric brain tumor survivors

INTRODUCTION

Treatment of childhood brain tumors, including surgical resection and especially external beam radiation, often results in endocrine complications manifested by hypopituitarism, which can involve growth hormone deficiency, hypothyroidism, adrenal insufficiency, disorders of puberty, diabetes insipidus, and hypothalamic obesity.

AREAS COVERED

A comprehensive literature search was conducted on Medline (publications from the 1990s to 01/2019) including systematic reviews, meta-analyses, longitudinal controlled studies, retrospective cohort studies, and case reports. Herein, we present an up-to-date review of the current literature regarding endocrine sequellae of childhood brain tumor survivors.

EXPERT OPINION

Late endocrine sequellae can arise many years after the initial treatment of tumor, so at least annual surveillance of growth, puberty, weight, development, and endocrine status is recommended for at least 10 years after tumor therapy. This follow up should encompass childhood and adulthood among survivors. If found early, outcomes of endocrinopathies are favorable when treated appropriately. Newer tumor therapy modalities, such as proton beam radiation, offer the potential for fewer endocrine complications, but such benefit has yet to be demonstrated, and more research into short- and long-term outcomes is needed.

Long-term effects on growth, development, and metabolism of ALL treatment in childhood

INTRODUCTION

One aim of the long-term care in survivors from acute lymphoblastic leukemia (ALL) during childhood is to avoid or limit complications caused by aggressive therapeutic strategies.

AREAS COVERED

ALL survivors are a heterogeneous group according to therapeutic protocols. In the last decades, cranial radiotherapy (cRT) has been largely replaced by intrathecal chemotherapy (CT) with a reduction of endocrine sequelae. Published studies are generally difficult to be interpreted because patients were treated according to different risk-adapted protocols and results are conflicting. We perform this review on endocrine long-term effects in childhood ALL survivors focusing on studies published in the last decades. Articles were selected using the following terms (Mesh terms): 'acute lymphoblastic leukemia' AND 'survivors' AND 'childhood' AND 'growth/puberty/fertility/obesity/metabolic syndrome/bone'.

EXPERT COMMENTARY

Most childhood ALL survivors treated with CT alone attain normal height and have adequate pubertal development. Despite recent protocols improvements, ALL survivors still develop long-term metabolic complications (overweight, obesity, and cardiovascular disease) especially the female gender and patients with an increased body mass index (BMI) at diagnosis. The aim of this review is to describe the state of the art on these topics. We should be able to anticipate, prevent, and treat endocrine long-term morbidities through a well-established follow-up strategy.

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.

Late endocrine effects of childhood cancer

The cure rate for paediatric malignancies is increasing, and most patients who have cancer during childhood survive and enter adulthood. Surveillance for late endocrine effects after childhood cancer is required to ensure early diagnosis and treatment and to optimize physical, cognitive and psychosocial health. The degree of risk of endocrine deficiency is related to the child's sex and their age at the time the tumour is diagnosed, as well as to tumour location and characteristics and the therapies used (surgery, chemotherapy or radiation therapy). Potential endocrine problems can include growth hormone deficiency, hypothyroidism (primary or central), adrenocorticotropin deficiency, hyperprolactinaemia, precocious puberty, hypogonadism (primary or central), altered fertility and/or sexual function, low BMD, the metabolic syndrome and hypothalamic obesity. Optimal endocrine care for survivors of childhood cancer should be delivered in a multidisciplinary setting, providing continuity from acute cancer treatment to long-term follow-up of late endocrine effects throughout the lifespan. Endocrine therapies are important to improve long-term quality of life for survivors of childhood cancer.

Radiation-Induced Growth Retardation and Microstructural and Metabolite Abnormalities in the Hippocampus

Cranial radiotherapy (CRT) increases survival in pediatric brain-tumor patients but can cause deleterious effects. This study evaluates the acute and long-term impact of CRT delivered during childhood/adolescence on the brain and body using a rodent model. Rats received CRT, either 4 Gy fractions × 5 d (fractionated) or a cumulative dose of 20 Gy (single dose) at 28 d of age. Animals were euthanized 1 d, 5 d, or 3.5 mo after CRT. The 3.5 mo group was imaged prior to euthanasia. At 3.5 mo, we observed significant growth retardation in irradiated animals, versus controls, and the effects of single dose on brain and body weights were more severe than fractionated. Acutely single dose significantly reduced body weight but increased brain weight, whereas fractionation significantly reduced brain but not body weights, versus controls. CRT suppressed cell proliferation in the hippocampal subgranular zone acutely. Fractional anisotropy (FA) in the fimbria was significantly lower in the single dose versus controls. Hippocampal metabolite levels were significantly altered in the single dose animals, reflecting a heightened state of inflammation that was absent in the fractionated. Our findings indicate that despite the differences in severity between the doses they both demonstrated an effect on cell proliferation and growth retardation, important factors in pediatric CRT.

Effect of cancer treatment on hypothalamic-pituitary function

The past 30 years have seen a great improvement in survival of children and young adults treated for cancer. Cancer treatment can put patients at risk of health problems that can develop many years later, most commonly affecting the endocrine system. Patients treated with cranial radiotherapy often develop dysfunction of the hypothalamic-pituitary axis. A characteristic pattern of hormone deficiencies develops over several years. Growth hormone is disrupted most often, followed by gonadal, adrenal, and thyroid hormones, leading to abnormal growth and puberty in children, and affecting general wellbeing and fertility in adults. The severity and rate of development of hypopituitarism is determined by the dose of radiotherapy delivered to the hypothalamic-pituitary axis. Individual growth hormone deficiencies can develop after a dose as low as 10 Gy, whereas multiple hormone deficiencies are common after 60 Gy. New techniques in radiotherapy aim to reduce the effect on the hypothalamic-pituitary axis by minimising the dose received. Patients taking cytotoxic drugs do not often develop overt hypopituitarism, although the effect of radiotherapy might be enhanced. The exception is adrenal insufficiency caused by glucocorticosteroids which, although transient, can be life-threatening. New biological drugs to treat cancer can cause autoimmune hypophysitis and hypopituitarism; therefore, oncologists and endocrinologists should be vigilant and work together to optimise patient outcomes.

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

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

Blunted response to a growth hormone stimulation test is associated with unfavorable cardiovascular risk factor profile in childhood cancer survivors

BACKGROUND

Childhood cancer survivors (CCS) are at risk for growth hormone (GH) deficiency. CCS are also at increased risk for early mortality from cardiovascular (CV) disease, but the association between GH levels and CV risk remains poorly understood. The goal of this study was to examine the cross-sectional association between stimulated GH levels and CV risk factors in CCS younger than 18 years.

PROCEDURE

A total of 276 CCS (147 males, 14.4 ± 2.6 years) ≥5 years after cancer diagnosis, and 208 sibling controls (112 males, 13.6 ± 2.4 years) participated in this cross-sectional study, which included anthropometry, body composition, and metabolic studies. Blunted response (BR) was defined as peak GH level <7 µg/L after clonidine and arginine. Insulin sensitivity (M(lbm) ) was measured by euglycemic hyperinsulinemic clamp. Statistical analyses used linear and logistic regression accounting for sibling clustering, adjusted for age, sex, Tanner stage, and adiposity.

RESULTS

Thirty-four (12%) CCS showed BR to GH stimulation. BR CCS were shorter and had a lower IGF-1 than controls; only 6 of 34 received cranial radiation therapy. CCS with normal stimulated GH response were similar to controls for CV risk factors. Conversely, BR CCS had greater adiposity, higher lipids, and lower M(lbm) than controls. Differences in lipids and M(lbm) between BR CCS and controls remained significant after adjustment for BMI or visceral fat.

CONCLUSIONS

BR to GH stimulation is prevalent in CCS youth and is associated with an unfavorable CV risk factor profile. Further studies are needed to establish the mechanisms of these associations.

United States multicenter study of factors predicting the persistence of GH deficiency during the transition period between childhood and adulthood

Background

Many patients with childhood-onset growth hormone (GH) deficiency do not fulfill diagnostic criteria for GH deficiency (GHD) after attainment of adult height and may not require long-term GH treatment. Patients with history of idiopathic GHD (IGHD) pose the greatest management dilemma, as data regarding factors predictive of persistent GHD in this group are lacking.

Objectives

The objective of this study was to assess potential predictors of persistent GHD in a US patient cohort during transition from childhood to adulthood, particularly in patients with history of IGHD.

Methods

We studied 73 US patients with history of childhood-onset GHD screened at 21 US pediatric endocrine centers for a randomized clinical trial of GH replacement after attainment of adult height. The cohort comprised 42 boys/men and 31 girls/women aged14–22 years, who had received ≥1 year of GH treatment and had completed linear growth. The main outcome measures were sensitivity, specificity, positive and negative predictive values (PPV, NPV) of clinical and hormonal factors for persistent GHD (defined a priori in this study as peak GH < 5 μg/L).

Results

For the cohort as a whole, the best predictors of persistent GHD (100% PPV) were history of organic hypothalamic-pituitary disorder or ≥2 additional pituitary hormone deficiencies (PHD). Best predictors of persistent GHD in patients with childhood history of IGHD were standard deviation scores (SDS) for serum insulin-like growth factor binding protein-3 (IGFBP-3) below -2.0, and for insulin-like growth factor-I (IGF-I) below -5.3 (measured ≥6 weeks after completion of GH treatment; PPV 100% for both), and age <4 years at original diagnosis (PPV 89%). IGF-I above -1.6 SDS had 100% NPV.

Conclusions

US patients with an organic cause of childhood-onset GHD or ≥2 additional PHDs may not require GH stimulation testing to reconfirm GHD after completion of childhood treatment. In contrast, patients with idiopathic childhood-onset GHD almost invariably require retesting, as GHD persists in only a minority (those who were very young at initial diagnosis and those who have subnormal IGFBP-3 or extremely low IGF-I after completion of childhood treatment). Subnormal posttreatment IGF-I (<-2.0 SDS) lacked predictive power for persistent GHD, whereas IGF-I > -1.6 SDS was 100% predictive of GH sufficiency.

The limited screening value of insulin-like growth factor-I as a marker for alterations in body composition in very long-term adult survivors of childhood cancer

BACKGROUND

The clinical relevance of low IGF-I levels, caused by cranial radiotherapy, in adult childhood cancer survivors has not been studied extensively. We evaluated whether IGF-I is a useful marker for altered body composition and growth hormone deficiency (GHD) in this group.

PROCEDURE

We analyzed retrospective data from 610 adult childhood cancer survivors, retrieved from the late effects clinic. Median age at diagnosis was 6 years (interquartile range 3-11) and follow-up time was 18 years (13-24). We assessed IGF-I standard deviation scores (SDS), anthropometrical measures, growth hormone stimulation tests in patients with clinical signs of GHD, and measures of body composition (assessed by dual X-ray absorptiometry, Lunar Prodigy).

RESULTS

In 58 cranially irradiated acute leukemia survivors (25 Gy (24-25)) and 56 locally irradiated brain tumor survivors (42 Gy (35-54)) we found significantly lower IGF-I SDS (P < 0.001), lower height SDS (P < 0.001), higher body mass index (P = 0.01), higher waist-hip ratio (WHR; P = 0.001), higher total fat percentage SDS (P < 0.001), and lower lean body mass SDS (P < 0.001), as compared to 452 not cranially irradiated survivors. IGF-I showed a weak inverse correlation with BMI (r = -0.12, P = 0.04), WHR (r = -0.15, P = 0.01), total fat percentage (r = - 0.14, P = 0.02), and a positive correlation with lean body mass (r = 0.15, P = 0.01). In patients with low IGF-I levels, IGF-I did not significantly differ between subjects with and without GHD as determined by GH-stimulation testing (P = 0.39).

CONCLUSION

This study shows that IGF-I has limited value as a marker for alterations in body composition in adult childhood cancer survivors.

Obesity in patients with acute lymphoblastic leukemia in childhood

Acute lymphoblastic leukemia is the most common malignancy in childhood. Continuous progress in risk-adapted treatment for childhood acute lymphoblastic leukemia has secured 5-year event-free survival rates of approximately 80% and 8-year survival rates approaching 90%. Almost 75% of survivors, however, have a chronic health condition negatively impacting on cardiovascular morbidity and mortality. Obesity can be considered one of the most important health chronic conditions in the general population, with an increasing incidence in patients treated for childhood cancers and especially in acute lymphoblastic leukemia survivors who are, at the same time, more at risk of experiencing precocious cardiovascular and metabolic co-morbidities. The hypothalamic-pituitary axis damage secondary to cancer therapies (cranial irradiation and chemotherapy) or to primary tumor together with lifestyle modifications and genetic factors could affect long-term outcomes. Nevertheless, the etiology of obesity in acute lymphoblastic leukemia is not yet fully understood. The present review has the aim of summarizing the published data and examining the most accepted mechanisms and main predisposing factors related to weight gain in this particular population.

The potential of proton beam therapy in paediatric cancer

A group of Swedish oncologists and hospital physicists have estimated the number of patients in Sweden suitable for proton beam therapy. The estimations have been based on current statistics of tumour incidence, number of patients potentially eligible for radiation treatment, scientific support from clinical trials and model dose planning studies and knowledge of the dose-response relations of different tumours and normal tissues. It is estimated that in paediatric cancers, proton beams are of potential importance in 80-100 children annually in Sweden. About 20 of the patients have medulloblastoma. The main purpose is to reduce late sequelae, but these are also increased chances to avoid myelosupression during e.g. concomitant chemo-radiation and to further intensify the chemotherapy.

Late effects in long-term survivors after treatment for childhood acute leukemia

BACKGROUND

This is a report of late effects in childhood cancer survivors seen in the follow-up clinic of a single institution.

MATERIALS AND METHODS

There were 324 acute leukemia survivors in the database of the Long Term Follow Up Clinic of Children's National Medical Center from January 1, 1997, through June 30, 2005.

RESULTS

Of the 324 acute leukemia survivors, 228 were white, 48 black, 20 Hispanic, and 12 other. Their follow-up time was 0 to 25 years (mean 5.3 years). One or more adverse events occurred in 74.1% of the 324 survivors. Defective physical growth was most commonly reported, followed by disturbed neurocognitive function, emotional difficulties, cardiac abnormalities, hypertension, osteoporosis/osteopenia, fractures, and second neoplasms. More black and Hispanic children had acute myeloid leukemia, relapses, cardiac problems, and hypertension than white and other subjects.

CONCLUSION

Childhood cancer survivors require lifelong monitoring, with prompt identification and treatment of adverse late effects.

Late endocrine sequelae after radiotherapy of pediatric brain tumors are independent of tumor location

INTRODUCTION

Irradiation of brain tumors (BT) in children can lead to the loss of pituitary function, predominantly manifesting as deficiencies in GH and ACTH.

OBJECTIVE

To assess the incidence and nature of pituitary deficiency in relation to initial tumor location in children after radiotherapy of BT.

METHODS

Twenty survivors (16 males and 4 females) of radiation-treated BT aged 1.4-10.9 (median 3.6) yr at diagnosis were studied, 10 with supratentorial and 10 with infratentorial BT. Radiation doses to the hypothalamus- pituitary (HP) area ranged from 30 to 54 (median 45) Gray. Follow-up was 9.4-16.9 (median 12.2) yr. Basal pituitary hormone levels were measured every 6 months. When growth failure became evident or pituitary deficiency was suspected, provocation tests of the HP axis were performed to assess GH, ACTH, and TSH function.

RESULTS

GH deficiency (GHD) developed in 17/20 (85%) children. In 10 patients, it occurred 4 yr after radiotherapy and in 2, 11 and 12 yr after radiotherapy. Six (30%) patients developed secondary hypothyroidism and 4 (20%) developed ACTH deficiency. Precocious puberty occurred in 2 girls. The course of development and the severity of hormone deficiencies were similar for supratentorial and infratentorial tumors.

CONCLUSION

The major hormonal effect of BT irradiation in children is GHD, which may sometimes take more than 10 yr to manifest. We confirm findings by others that ACTH insufficiency occurs less frequently in children than reported for adults. Tumor location has no prognostic significance regarding the loss of HP function.

Adiposity in childhood cancer survivors: insights into obesity physiopathology

As childhood cancer treatment has become more effective, survival rates have improved, and a number of complications have been described while many of these patients reach adulthood. Obesity is a well-recognized late effect, and its metabolic effects may lead to cardiovascular disease. Currently, studies concerning overweight have focused on acute lymphocytic leukemia and brain tumors, since they are at risk for hypothalamic-pituitary axis damage secondary to cancer therapies (cranial irradiation, chemotherapy, and brain surgery) or to primary tumor location. Obesity and cancer have metabolic syndrome features in common. Thus, it remains controversial if overweight is a cause or consequence of cancer, and to date additional mechanisms involving adipose tissue and hypothalamic derangements have been considered, comprising premature adiposity rebound, hyperinsulinemia, leptin regulation, and the role of peroxisome proliferator-activated receptor γ. Overall, further research is still necessary to better understand the relationship between adipogenesis and hypothalamic control deregulation following cancer therapy.

Pediatric medulloblastoma: toxicity of current treatment and potential role of protontherapy

Post-operative craniospinal irradiation and systemic chemotherapy are both necessary in the treatment of pediatric medulloblastoma. Late toxicity is a major problem in long term survivors and significantly affects their quality of life. We have systematically reviewed the literature to examine data on late toxicity, specifically focusing on: endocrine function, growth and bone development, neurocognitive development, second cancers, ototoxicity, gynecological toxicity and health of the offspring, cardiac toxicity and pulmonary toxicity. In this paper, we describe qualitatively the kind of detected side effects and, whenever possible, try to assess their incidence and the relative role of craniospinal irradiation (as opposed to other treatments and to the disease itself) in producing them. Subsequently we examine the possible approach to reduce unwanted effects from craniospinal irradiation to target and non-target tissues and we consider briefly the role of hyperfractionation, tomotherapy and IMRT. We describe the characteristics of protontherapy and its potential for non-target tissues toxicity reduction reviewing the existing physical and dosimetric studies and the (still very limited) clinical experiences. Finally we propose intensity modulated spot scanning protontherapy with multiportal simultaneous optimization (IMPT) as a possible tool for dose distribution optimization within different areas of CNS and potential reduction of target tissues toxicity.

Factors influencing the growth hormone peak and plasma insulin-like growth factor I in young adults with pituitary stalk interruption syndrome

BACKGROUND

The diagnostic criteria for growth hormone (GH) deficiency (GHD) in adolescents and young adults are not yet clearly established.We evaluated the factors influencing the GH peak and plasma insulin-like growth factor (IGF) I in order to determine the cut-off limits for the diagnosis of GHD during the transition period.

METHODS

21 patients treated for GHD due to pituitary stalk interruption syndrome at 5.7 +/- 4.1 years were reevaluated at 16.0 +/- 1.8 years, 0.6 +/- 0.6 years after the end of GH treatment. Group 1 had isolated GHD (n = 9) and group 2 had multiple pituitary deficiencies (n = 12), including deficiencies of thyroid stimulating (n = 12), adrenocorticotropin (n = 8) and gonadotropin (n = 9) hormones.

RESULTS

At diagnosis, group 1 had a greater pituitary height (2.8 +/- 1.2 vs 1.6 +/- 1.1 mm, P = 0.03) and GH peak (3.8 +/- 1.9 vs 1.6 +/- 1.5 ng/ml, P < 0.02) than did group 2.At last evaluation, group 1 had greater GH peak (3.9 +/- 1.9 vs 0.2 +/- 0.4 ng/ml, P = 0.0001) and plasma IGF I (211 +/- 88 vs 78 +/- 69 ng/ml, P < 0.002) than did group 2. No group 1 and 9 group 2 patients had an undetectable GH peak, while the 3 others had GH peak below 1 ng/ml.The GH peak decreased between diagnosis and last evaluation only in group 2 (P < 0.008).

CONCLUSION

The GH peak response to pharmacological stimulation and the plasma IGF I concentration in young adults with GHD of childhood onset depend on the presence of additional pituitary deficiencies, reflecting a more severe defect of the hypothalamic-pituitary axis. The sex steroids cannot increase the IGF I if the GH secretion is zero.

Detection of metabolic syndrome features among childhood cancer survivors: a target to prevent disease

Along with the growing epidemic of obesity, the risk of atherosclerosis, cardiovascular disease morbidity, and mortality are increasing markedly. Several risk factors for cardiovascular disease, such as visceral obesity, glucose intolerance, arterial hypertension, and dyslipidemia commonly cluster together as a condition currently known as metabolic syndrome. Thus far, insulin resistance, and endothelial dysfunction are the primary events of the metabolic syndrome. Several groups have recommended clinical criteria for the diagnosis of metabolic syndrome in adults. Nonetheless, in what concerns children and adolescents, there are no unified definitions, and modified adult criteria have been suggested by many authors, despite major problems. Some pediatric disease states are at risk for premature cardiovascular disease, with clinical coronary events occurring very early in adult life. Survivors of specific pediatric cancer groups, particularly acute lymphocytic leukemia, central nervous system tumors, sarcomas, lymphomas, testicular cancer, and following bone marrow transplantation, may develop metabolic syndrome traits due to: hormonal deficiencies (growth hormone deficiency, thyroid dysfunction, and gonadal failure), drug or radiotherapy damage, endothelial impairment, physical inactivity, adipose tissue dysfunction, and/or drug-induced magnesium deficiency. In conclusion, some primary and secondary prevention remarks are proposed in order to reduce premature cardiovascular disease risk in this particular group of patients.

Leptin assessment in acute lymphocytic leukemia survivors: role of cranial radiotherapy?

Leptin has been hypothesized to play a role in the development of obesity in leukemia survivors, particularly those who have received cranial radiotherapy. This cross-sectional study evaluated the relationship between leptin levels and body mass index (BMI) in a sample of 26 acute lymphocytic leukemia survivors of both sexes, treated with and without cranial irradiation, aged 7.6 to 17 years, at a mean 3.4+/-2.0 years off treatment. There were significantly more males among the irradiated group (P<0.001), even though no differences were encountered in pubertal stage (P=1.000), BMI standard deviation score (mean+/-SD) (0.68+/-1.00 vs. 1.19+/-0.78; P=0.164), or leptin concentrations (17.01+/-17.04 vs. 23.3+/-13.4; P=0.309). Nonetheless, there was a positive correlation between the natural logarithm of leptin and BMI standard deviation score [t(22)=2.348, P=0.028], however, no differences were recorded among irradiated and nonirradiated patients [F(2,22)=0.384, P=0.685]. When this relationship was compared between sexes, a significant difference was encountered [F(2,22)=4.907, P=0.017], with males having the strongest association (R(2)males=65.5%, R(2)females=34.7%). Leptin is a reliable adiposity index as it strongly correlates with BMI. Overall, the current data suggest that cranial irradiation did not play a role upon this relationship; however, sex differences influenced positively this correlation.

Sensitivity of anterior pituitary hormones to irradiation

Cranial irradiation is used in the management of a diverse group of intracranial pathologies. However, if any part of the hypothalamic-pituitary axis is included in the radiation field, there is a risk of developing neuroendocrine dysfunction. Growth hormone is the most radiosensitive of the anterior pituitary hormones, followed by the gonadotropins, adrenocorticotropic hormone and thyroid-stimulating hormone. A number of factors determine both the occurrence and severity of hypothalamic-pituitary dysfunction, including: the dose of radiation received by the hypothalamic-pituitary axis (determined by a number of factors including total dose and fractionation schedule and ultimately expressed as the biological effective dose); length of time since cranial irradiation; age of the patient at the time of cranial irradiation; type of radiotherapy administered; and the different inherent radiosensitivities of the anterior pituitary hormones. These neuroendocrine abnormalities usually develop a number of years after the initial insult and, therefore, patients who have received cranial irradiation should receive annual endocrine assessments. The establishment of endocrine late-effect clinics for the survivors of childhood cancers have gone some way to addressing this problem; however, other groups of patients, particularly those receiving cranial irradiation in adult life, may not have systematic endocrine assessment.

Optic pathway gliomas

Optic pathway gliomas represent approximately 5% of all pediatric intracranial tumors. While these tumors are most frequently low grade astrocytomas, they follow a highly variable clinical course, and accordingly, there is much debate regarding their optimal management. Their propensity to occur in very young children and infants further complicates selection of therapy. Historically, surgery and radiotherapy have played a primary role in management, however, in the last 15 years, chemotherapy has evolved into the first-line treatment of choice. Nonetheless, chemotherapy frequently fails, but serves to delay implementation of radiotherapy or surgery until the child has progressed neuropsychologically. An overall favorable prognosis for this tumor emphasizes the need for careful selection of therapy. Herein, we review the major features of optic pathway glioma, including epidemiology, pathology, therapeutic interventions, outcome, and treatment sequelae.

Growth hormone deficiency after chemotherapy for acute lymphoblastic leukemia in children who have not received cranial radiation

Chemotherapy-related growth failure is a significant problem in children with acute lymphoblastic leukemia (ALL) and other childhood cancers. Growth impairment after cranial radiation (CR) can result in diminished adult height, but growth failure following chemotherapy without CR is usually followed by catch-up growth and normal adult height.1 A retrospective review of 347 ALL survivors registered in our Long Term Follow Up (LTFU) Clinic, since 1997 revealed that 109 had received CR; 3, total body irradiation (TBI); and 235, neither CR nor TBI. For patients whose growth velocity slowed, growth hormone (GH) levels and pediatric endocrinology referrals were obtained. Among the 112 ALL survivors who had received some form of CR, 5 had significant growth failure with growth hormone deficiency (GHD). Among the 235 ALL survivors treated with chemotherapy without CR, 2 were diagnosed with growth failure and GHD. We report the two survivors of childhood ALL treated with chemotherapy without CR who required GH replacement due to absence of catch-up growth. A 15-year-old boy and a 12-year-old girl, off therapy for 9 and 6 years, respectively, were evaluated for decreased growth velocity and failure of catch-up growth. Peak GH responses to stimulation using arginine and clonidine were 3.4 and 3.0 ng/ml, respectively (normal >10 ng/ml). Other causes of growth failure were ruled out, and GH replacement therapy was instituted. Their chemotherapy had included methotrexate, 6 mercaptopurine, vincristine, adriamycin, cyclophosphamide, L-asparaginase, dexamethasone, cytarabine, 6 thioguanine, and intrathecal methotrexate. The growth of all children treated with intensive chemotherapy, regardless of whether CR was administered, should be closely monitored with measurement of standing height at 6 months intervals until growth is complete.

Seqüelas endócrinas da radioterapia no tratamento do câncer na infância e adolescência

A radioterapia resulta em endocrinopatias, osteoporose, obesidade e seqüelas neurológicas em pacientes tratados por câncer. A deficiência de GH é a complicação mais freqüente no eixo hipotálamo-hipofisário. A freqüência, prazo de surgimento e gravidade da deficiência de GH dependem da dose recebida durante a irradiação craniana, mas idade à radioterapia e fracionamento da dose também são variáveis importantes. Outras anormalidades do eixo hipotálamo-hipofisário são igualmente dose-dependentes. Baixas doses de irradiação induzem puberdade precoce ou avançada, enquanto altas doses provocam deficiência gonadotrópica. Complicações endócrinas secundárias à irradiação periférica, como distúrbios gonadais ou tireoidianos são descritos. Mesmo com secreção normal de GH, o crescimento pode ser comprometido por lesões ósseas após irradiação corporal total ou crânio-espinhal. Resultados melhores sobre a estatura final têm sido obtidos com reposição de GH em associação com o tratamento da puberdade precoce ou avançada. O objetivo desta revisão é a abordagem das seqüelas endócrinas tardias da radioterapia.

Growth patterns and final height of survivors of childhood leukemia

Growth patterns of 85 survivors of childhood leukemia were analyzed retrospectively. All patients remained in first remission with no central nervous system involvement. The mean age at diagnosis was 5.8 +/- 3.6 years. The diagnoses were acute lymphoblastic leukemia (ALL) in 68 patients (80%) and acute non-lymphoblastic leukemia (ANLL) in 17 patients (20%). All except two patients received cranial irradiation: 51 patients with 1,800 cGy and 32 patients with 2,400 cGy. Mean height SDS was -0.7 +/- 1.36 at the time of diagnosis, which decreased to -0.92 +/- 1.31 by the end of treatment, and further decreased to -1.14 +/- 1.38 at 6 years after cessation of treatment. Mean weight SDS was -0.55 +/- 1.13 at the time of diagnosis, increasing slightly to -0.39 +/- 1.02 at the end of treatment, and decreasing to -0.46 +/- 1.65 at 6 years after cessation of treatment. Of these survivors, 51 patients (26 boys and 25 girls) reached a final height that was 1.04 SDS or 5.3 cm less than their target height. There was no difference of height and weight SDS between patients with ALL and ANLL. Girls and boys had different growth patterns. Girls had a slightly increased height SDS and gained more weight after cessation of treatment, resulting in less final height deficit and overweight for height, whereas boys had further height and weight reduction resulting in more deficit of final height.

Obesity in adult survivors of childhood acute lymphoblastic leukemia: a report from the Childhood Cancer Survivor Study

PURPOSE

To determine whether adult survivors (>or= 18 years of age) of childhood acute lymphoblastic leukemia (ALL) are at increased risk for obesity and to assess patient and treatment variables that influence risk.

PATIENTS AND METHODS

A retrospective cohort of participants of the Childhood Cancer Survivor Study was used to compare 1,765 adult survivors of childhood ALL to 2,565 adult siblings of childhood cancer survivors. Body-mass index (BMI; kilograms per square meter), calculated from self-reported heights and weights, was used to determine the prevalence of being overweight (BMI, 25-29.9) or obese (BMI >or= 30.0). Polytomous logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for being overweight or obese among ALL survivors relative to the sibling control group.

RESULTS

The age- and race-adjusted OR for being obese in survivors treated with cranial radiation doses >or= 20 Gy in comparison with siblings was 2.59 for females (95% CI, 1.88 to 3.55; P <.001) and 1.86 for males (95% CI, 1.33 to 2.57; P <.001). The OR for obesity was greatest among females diagnosed at 0 to 4 years of age and treated with radiation doses >or= 20 Gy (OR, 3.81; 95% CI, 2.34 to 5.99; P <.001). Obesity was not associated with treatment consisting of chemotherapy only or with cranial radiation doses of 10 to 19 Gy.

CONCLUSION

Cranial radiotherapy >or= 20 Gy is associated with an increased prevalence of obesity, especially in females treated at a young age. It is imperative that healthcare professionals recognize this risk and develop strategies to enhance weight control and encourage longitudinal follow-up.

Long-term cognitive outcome, brain computed tomography scan, and magnetic resonance imaging in children cured for acute lymphoblastic leukemia

BACKGROUND

Prevention of meningeal recurrence achieved by intrathecal methotrexate (MTX) and systemic chemotherapy is part of standard acute lymphoblastic leukemia (ALL) treatment. Cranial irradiation has been a routine part of past protocol treatment but is currently reserved only for select subsets of patients. Central nervous system (CNS) prophylaxis may cause brain abnormalities such as intracerebral calcifications, cerebral atrophy, and white matter alterations. In addition, long-term neuropsychologic sequelae following CNS prophylaxis have been investigated marginally in children cured for ALL.

METHODS

To explore possible correlations between neuroimaging findings and neuropsychologic outcome, we used detailed cognitive tests to evaluate 21 children with ALL who received cranial irradiation (range, 18-24 Gy) plus intrathecal MTX as CNS prophylaxis. All children were followed prospectively once a year by cerebral computed tomographic scan and magnetic resonance imaging. All patients had continuous complete disease remission for at least 4 years and cognitive tests were performed after neuroradiologic examinations.

RESULTS

White matter abnormalities were associated with poor performance only in a task exploring visual motor integration in about 50% of patients. Intracerebral calcifications correlate with the number of intrathecal MTX doses and with low scores in total intellectual quotient, performance intellectual quotient, and significant impairment in attention and visual motor integration tests. Girls are more vulnerable to the effects of CNS prophylaxis, whereas age at treatment and radiotherapy dose are not relevant to neuropsychologic outcome.

CONCLUSIONS

Our results indicate the need for careful follow-up of children's cognitive abilities because global intellectual measures often fail to detect specific disorders that may cause learning difficulties. Moreover, as the clinical implications of neuroimaging findings are often limited, periodic extensive evaluation by specific neurocognitive tests of mental abilities is recommended to detect early signs of cognitive impairment.

Primitive neuroectodermal tumors/medulloblastoma

The therapy for medulloblastoma/primitive neuroectodermal tumors of the central nervous system is surgery, followed by combination chemo-radiotherapy. The radiation field is the entire craniospinal axis, which is only avoided when treating infants. The treatment is, therefore, lengthy and toxic. Less aggressive therapy is given to patients who clinically appear to have less evidence of disease. Intensive basic research has begun to identify genetic factors of the disease, but these remain far from clinical application.